SERVICE MANUAL GARDA M90F.24S M90F.28S M90F.32S M90F.24SR M90F.28SR

Transcription

1 Wall hug, fa flue, room sealed gas boiler SERVICE MANUAL GARDA Models: G.C. Appl. No. M90F.24S M90F.28S M90F.32S M90F.24SR M90F.28SR Leave this maual adjacet to the gas meter Biasi UK Ltd Newma Park, Wester Way Wedesbury, WS10 7BJ Sales Tel No: Sales Fax No: Service Tel No: Service Fax No:

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3 Table of cotets 1 Overall iformatio Overall View Hydraulic diagram Geeral access ad emptyig hydraulic circuits Nomeclature Body paels Cotrol pael Access to the sealed chamber Emptyig the primary circuit Emptyig the d.h.w. circuit Diagrams Wirig diagram M90F.24S M90F.28S, M90F.32S Wirig diagram M90F.24SR, M90F.28SR Fuctioal flow diagrams Circuit voltages Fault fidig Primary heat exchager Characteristics Removal Cleaig D.h.w. heat exchager Fuctio Removal Pump Fuctio Checks Removal Three way diverter valve Fuctio Checks Removal of the electric actuator Removal of the diverter group ad its iteral parts Electroic cotrol p.c.b Fuctio Selectio ad adjustmet devices Checkig the temperature Operatio/Service lamps Dip--- switch selectors Settig jumpers Igitio gas pressure adjustmet Max c.h. power adjustmet Checks Removal of the electroic cotrol p.c.b Thermal cotrol i the mode Thermal cotrol i the mode Full sequece igitio device Fuctio Checks Removal Igitio ad cotrol sequece Modulatig gas valve Fuctio Nomeclature of the parts Adjustmet Checks Removal of the o--- off operators coils Removal of the gas valve Primary circuit flow switch Fuctio Checks Removal Expasio vessel ad temperature-- pressure gauge Fuctio Checks Removal of the expasio vessel Removal of the temperature---pressure gauge D.h.w. flow switch, filter ad flow limiter Fuctio Nomeclature ad locatio of parts Checks Removal of the flow switch sesor Removal of the flow switch group ad d.h.w. circuit filter Flow limiter Temperature probe Fuctio Checks Removal By--pass valve Fuctio Removal Fa, veturi device ad Air pressure switch Fuctio Checks Removal of the Fa Ispectio ad removal of the veturi device Removal of the Air pressure switch Igitio ad detectio electrodes Fuctio Checks Removal Safety thermostat Fuctio Checks Removal Short spare parts list

4 1 Overall iformatio 1.1 Overall View Air pressure switch Fa Mai heat exchager Safety thermostat Expasio vessel Burer Igitio electrodes Detectio electrode Diverter valve Mai circuit flow switch Gas valve Cotrol pael Combustio chamber Automatic air release valve D.h.w. temp. probe Pump D.h.w flow switch D.h.w. heat exchager 1.2 Hydraulic diagram Cetral heatig (c.h.) operatio Domestic hot water (d.h.w.) operatio C.h. water retur C.h. water flow D.h.w. ilet D.h.w outlet 2

5 2 Geeral access ad emptyig hydraulic circuits 2.1 Nomeclature A Fig. 2 3 To remove the side paels loose the screws B ad C (Fig. 3), brig the base of the paels away from the boiler ad lift them, freeig them from the top hooks. D 5 4 Fig. 1 1 Right side pael 2 Frot pael B 3 Cotrol pael lid 4 Cotrol pael cover 5 Service pael 6 Left side pael 2.2 Body paels For the most part of the check ad maiteace operatios it is ecessary to remove oe or more paels of the case. Thesidepaelscaberemovedolyaftertheremoval of the frot pael. To remove the frot pael remove screws A (Fig. 2), lift the pael ad remove it. Fig bottom view of the boiler 2.3 Cotrol pael To gai access to the parts located iside the cotrol pael proceed as follows: 1 Remove the frot pael of the case 2 Loose the screws B ad C (Fig. 3). 3 Remove the screws D 4 Move the lower part of the side paels as idicated i Fig. 4 ad pull the cotrol pael. Whe completely pulled out, the pael ca rotate 45û dowwards to facilitate the service operatios o the iteral parts. C 3

6 Geeral access ad emptyig hydraulic circuits To gai access to the parts cotaied i the sealed chamber it is ecessary to remove the lid of the sealed chamber. For this purpose, remove the frot ad side paels of the case, remove the screws G as idicated i Fig. 6 ad remove the lid. 2.5 Emptyig the primary circuit Fig. 4 5 Remove the screws E ad remove the service pael (Fig. 5); 6 To gai access to the electroic regulatio PCB ad the full sequece igitio device remove the screws F ad remove the cotrol pael lid (Fig. 5); F 1 Close the c.h. circuit flow ad retur cocks H. (Fig. 7). J H E H Fig Access to the sealed chamber F Fig bottom view of the boiler 2 Remove the frot ad right paels of the boiler. 3 Ope the drai tap I (Fig. 8) util the boiler is completely emptied. 4 Close drai tap agai oce the emptyig has bee completed. G G I Fig Emptyig the d.h.w. circuit 5 Close the d.c.w. ilet cock J (Fig. 7); 6 Ope oe or more hot water taps util the boiler has bee completely emptied. Fig. 6 4

7 3 Diagrams 3.1 Wirig diagram M90F.24S M90F.28S M90F.32S Wirig diagram for boiler equiped with full sequece igitio device type: ceza Electrical supply termial block L N m g/v c g/v Fa M ~ c Air pressure switch COM gr Safety thermostat gr b Flame detectio electrode gr igitio electrodes g/v g/v g/v g/v 1 m g/v c c r c g/v c gr b gr c c m b r r r J11 b c v b r Modulatig gas valve gr b g/v DHW temperature probe NTC t r r r 2 b c 1 DHW flow switch c t COM c 3 CH temperature Primary probe NTC pressure switch 2 1 r c M ~ 3 Three way diverter valve g/vm M ~ c r b v Time switch Pump m --- brow c --- blue --- black b --- white r --- red gr--- grey a --- orage g --- yellow g/v --- yellow/gree v --- gree 5

8 Diagrams 3.2 Wirig diagram M90F.24SR, M90F.28SR Wirig diagram for boiler equiped with full sequece igitio device type: ceza Electrical supply termial block L N m g/v c g/v Fa M ~ c Air pressure switch COM gr Safety thermostat gr b Flame detectio electrode gr igitio electrodes g/v g/v g/v g/v 1 m g/v c c g/v c gr b gr c c m b J11 v b r Modulatig gas valve gr b g/v c COM t c CH temperature Primary probe NTC pressure switch g/vm M ~ c r b v Time switch Pump m --- brow c --- blue --- black b --- white r --- red gr--- grey a --- orage g --- yellow g/v --- yellow/gree v --- gree 6

9 Diagrams 3.3 Circuit voltages Eletric supply termial block 3waydiverter valve Fa 230~ 1 230~ 230~ ~ 230~ 230~ 0 Pump Modulatig Gas valve Safety thermostat durig c.h. or d.h.w. operatio Electrical voltages with burer o oly durig c.h. operatio oly durig d.h.w. operatio 7

10 4 Fault fidig Sectio of the maual! (ote ref. i brackets) Defect # Compoets to check --- (2) --- (3) --- (4) --- (5) TAG (8) --- (9) OFF OFF Appliace operatio lamp gree (1) Lock --- out sigal lamp red Power supply lie Gas supply lie Flue pipes C.h. circuit D.h.w. circuit D.h.w. heat exchager Pump Diverter valve D.h.w. flow switch Fuse (regulatio p.c.b.) Regulatio p.c.b. start igitio Fuctio selectors (reg. p.c.b) Gas valve (o---off operators) Gas valve (modulatig operator) Mai circuit flow switch D.h.w. filter Mai circuit temp. probe D.h.w. temp. probe By --- pass valve Fa ad veturi device Air pressure switch Igitio electrode Detectio electrode Safety thermostat Ijectors Expasio vessel Safety valve Pressure gauge The boiler does ot start either i c/h or d.h.w. mode. Fa still. By pressig the reset push---butto the boiler turs o ad operates correctly. By pressig the reset push---butto the boiler starts the igitio cycle. The burer does t light o, the igitio sparks cotiue ad the boiler locks agai. By pressig the reset push---butto the boiler starts the igitio cycle. The burer lights o, the igitio sparks cotiue ad the boiler locks agai. J J J J J (7) J J J J J J J ON --- fast pulses ON The burer does t light either i c.h. or d.h.w. mode. Fa tur. The burer does t light either i c.h. or d.h.w. mode. Fa does t tur. The boiler does t cotrol the d.h.w. temperature. Turig the d.h.w. temp. adjustmet kob has t effect o the modulatio of the flame. The boiler operates correctly o c.h. J J J J J J J J J J J J J J J J J fast pulses The boiler lights for a short while o c.h. Normal operatio o d.h.w. fuctio. J J J J ON --- f OFF 8

11 Compoets to check Sectio of the maual! (ote ref. i brackets) --- (2) --- (3) --- (4) --- (5) TAG (8) --- (9) Appliace operatio lamp gree (1) Gas valve (modulatig operator) Defect # Lock --- out sigal lamp red Power supply lie Gas supply lie Flue pipes C.h. circuit D.h.w. circuit D.h.w. heat exchager Pump Diverter valve D.h.w. flow switch Fuse (regulatio p.c.b.) Regulatio p.c.b. start igitio Fuctio selectors (reg. p.c.b) Gas valve (o---off operators) Mai circuit flow switch D.h.w. filter Mai circuit temp. probe D.h.w. temp. probe By --- pass valve Fa ad veturi device Air pressure switch Igitio electrode Detectio electrode Safety thermostat Ijectors Expasio vessel Safety valve Pressure gauge The boiler does ot supply d.h.w. (cold water from the tap). Regular operatio i c/h mode eve durig a drawig off d.h.w. J J J O c/h mode the temperature of the mai circuit reaches 75 C ad the c/h system does ot heat. The boiler operates correctly o d.h.w. mode. J J Icorrect modulatio J J J Noisy bolier J J --- ormal pulses s The boiler operates correctly but the gas pressure to the burer remais at miimum. J J Poor d.h.w. temperature J J J J J (10) ON - OFFF Low d.h.w. flow rate J J J Water leaks from the safety valve durig operatiooc/h J J J J Water leaks from the safety valve whe the boiler is off. J J J Note 1 For details see sectio 9.4 of this maual. Further useful iformatio ca be obtaied by switchig the electroic cotrol p.c.b. i the service operatio mode (see sectio 9.4 of this maual). 2 Check for 230V~ betwee lie (L) ad eutral (N) Verify the itegrity of supply cable, plug ad exteral fuses. Check the polarity of lie ad eutral coectio 3 Verify the soudess of the gas supply pipe, the positio of stop valves. Check the gas pressure at the ilet test poit of the gas valve (see sect. 10.3) with the boiler at rest ad durig operatio ad compare it with the values give o the istallatio booklet. 4 Check for soudess ad absece of obstructios. Verify that the flue termial is correctly istalled (see clearaces) ad esure that exhaust gas is ot sucked back by the boiler. 5 Check for soudess of the circuit ad verify its correct fillig (see also istallatio maual). 6 A jammed by --- pass could cause the over --- heatig of the mai circuit ad the itervetio of the safety thermostat. 7 Checkthemiimum gas pressure at the outlet test poit of the gas valve (see sect. 10.3) ad compare it with the value give o the istallatio booklet. 8 Verify the cleaess of ijectors. 9 Check the pressurizatio of the expasio vessel. Refer to the istallatio maual for proper values. 10 d.h.w. pressure too high or flow rate too high. If ecessary isert a flow rate limiter (13.6). 9

12 5 Primary heat exchager 5.1 Characteristics The primary heat exchager A i Fig. 9 has the fuctio of trasferrig heat produced from combustio of the gas to the water circulatig i it. C G F A B E D Fig. 9 The hydraulic circuit is composed of 8 elliptical pipes coected i parallel (Fig. 10). Fig Uscrew the coectio H (Fig. 12), lift the pipe I ad rotate it right the move it dowwards freeig it from the heat exchager coectio. 6 Remove the motor of the three way diverter valve (see sectio 8.3). 7 Completely uscrew the coectio J ad rotate the pipe K dowwards freeig it from the heat exchager coectio. 8 Remove the heat exchager by slidig it forwards. 9 Reassemble the boiler carryig out the removal operatios i reverse order. Fit the clips F with the arrow poitig upwards as illustrated i Fig. 11. I J H Fig Removal 1 Empty the primary circuit of the boiler. 2 Remove the case paels ad the sealed chamber lid (see sectio 2). 3 Remove the combustio chamber lid B by uscrewig the screws C (Fig. 11). 3b For model M90F.28S, M90F.28SR ad M90F.32S oly, remove the screw D ad the plate E. 4 Remove the clips F ad the safety thermostat G. It is ot ecessary to discoect it from the wirig. 10 K Fig Cleaig If there are deposits of soot or dirt betwee the blades of the heat exchager, clea with a brush or o---metallic bristle brush. I ay case, avoid ay actios that ca damage the protective varish with which the exchager has bee covered. Warig: After cleaig or replacemet as detailed above refer to sectio Combustio aalysis check i the chapter Maiteace of the istallatio istructios maual.

13 6 D.h.w. heat exchager 6.1 Fuctio The d.h.w heat exchager A i Fig. 13 allows the istataeous trasfer of heat from the primary hydraulic circuit to the water destied for d.h.w use. A 6.2 Removal 1 Remove the frot ad right had side paels of the case. 2 Empty the primary circuit ad the d.h.w circuit of the boiler. 3 Remove the motor of the three way diverter valve (see sectio 8.3). 4 Completely uscrew the two Alle key screws B (Fig. 15) which hold the exchager to the brass groups. B Fig. 13 The schematic structure is show i Fig. 14. Fig Move the exchager towards the rear of the boiler ad extract it. Reassemble the d.h.w. heat exchager carryig out the removal operatios i the reverse order. Attetio. Whe reassemblig the exchager be sure to put the off ceter locatio/securig pi idicated i Fig. 16 towards the left side of the boiler. Primary hydraulic circuit Domestic hot water circuit Fig. 14 Fig

14 7 Pump 7.1 Fuctio The pump A i Fig. 17 has the fuctio of makig the water i the mai circuit circulate through the mai heat exchager ad therefore through the c.h. system (durig the c.h. fuctio) or through the secodary heat exchager (durig the d.h.w. fuctio). A Check that the impeller is itegral with the rotor. With the boiler off remove the frot ad right had side case paels, lower the cotrol pael ad empty the primary circuit. Remove the pump head by udoig the screws which hold it to the pump body ad check that the impeller is firmly joied to the rotor. 7.3 Removal 1 Remove the frot ad right had side case paels 2 Empty the primary circuit of the boiler. 3 Extract ad lower the cotrol pael. 4 Discoect the coector B (Fig. 18). 5 Uscrew the coectio C ad move the pipe upwards freeig it from the outlet port of the pump. 6 Remove the fork D ad the capillary pipe. 7 Remove the lockig plate E right (Fig. 18). C B D Fig Checks 12 Check that the pump is ot seized ad that the movemet of the rotor is ot subject to mechaical impedimets. With the boiler off, remove the frot pael. Remove the air release plug of the pump ad tur the rotor with a screwdriver. Check the electrical cotiuity. With the boiler off, remove the frot pael ad discoect the coector B (Fig. 18). Measure the electrical resistace betwee the pump supply coectios. Electrical resistace of the widigs (at ambiet temperature) must be about 230 Ω Check the absece of startig defects. With the boiler off remove the frot case pael. Remove the air release plug from the pump. Start the boiler ad with a screwdriver, tur the rotor i the directio of the arrow. If there is a defect i startig, the rotor will begi to tur ormally oly startig it maually. Fig Loose the coectio F, remove thefork G ad the pipe H. 9 Uscrew the two screws I that hold the pump o theframe(fig. 19)adremovethepumptowards the frot of the boiler. Fig. 19 F Reassemble the pump carryig out the removal operatios i the reverse order. Whe reassemblig the pump, check the correct locatio of the O---rig gasket i the ilet port of the pump that seals the coectio betwee the pump ad the brass group. H I E G

15 8 Three way diverter valve 8.1 Fuctio The diverter valve A (Fig. 20) has the fuctio of modifyig the hydraulic circuit of the boiler by meas of a electric commad give by the electroic cotrol p.c.b. i order to sed the water that exits the primary heat exchager towards the c.h. system or towards the d.h.w. heat exchager. B 3 2 Spidle B ot visible 9,4 Kohm b = brow bu = blue bk = black bk bu b Ope circuit 230 V 0V 1 Fig D.h.w. mode B Spidle B visible Ope circuit A b = brow bu = blue bk = black bk bu b 9,4 Kohm Fig. 20 0V 230 V 8.2 Checks Check the electrical cotiuity Fig. 21 idicates the relatioship betwee the electric commad comig from the electroic cotrol p.c.b. ad the positio of the actuator B (brass spidle) whe the boiler operates i d.h.w. mode. Fig. 22 idicates the relatioship betwee the electric commad comig from the electroic cotrol p.c.b. ad the positio of the actuator B (brass spidle) whe the boiler operates i c.h. mode. I both figures the relatioship betwee the positio of the actuator ad the resistace of the motor widigs (the motor must be discoected from the wirig) is also give. Fig C.h. mode 8.3 Removal of the electric actuator 1 Remove the frot case pael. 2 Discoect the coectors C (Fig. 23). 3 Remove the fixig sprig D ad remove the actuator E. Reassemble the actuator carryig out the removal operatios i the reverse order. Whe reassemblig the actuator, refer to Fig. 21 or to the wirig diagram i sectio 3.1 for the correct wirig coectio. 13

16 Three way diverter valve C E 9 Uscrew the screw L ad remove the diverter group. D J Fig Removal of the diverter group ad its iteral parts 1 Remove the frot ad both side case paels. 2 Empty the primary circuit ad the d.h.w circuit of the boiler. 3 Remove the electric actuator (see sectio 8.3). 4 Remove the fixig sprig F (Fig. 24) ad remove the primary circuit flow switch G. 5 Discoect the c.h. temperature probe H. 6 Uscrew the coector I, the c.h. flow coector ad the d.h.w. outlet coector. Fig. 25 Rear view of the boiler 10 Refer to the exploded view i Fig. 26 to remove the iteral parts of the three way diverter valve. K L I H G F Fig Remove the d.h.w. heat exchager (see sectio 6.2). 8 Remove the fork J ad move away the pipe K (Fig. 25). Fig Reassemble the diverter group carryig out the removal operatios i the reverse order. 14

17 9 Electroic startig cotrol p.c.b. 9.1 Fuctio Ilet Iformatio O the Electroic startig cotrol p.c.b... Fuctio cotrol* C.h. temperature adjustmet* D.h.w. temperature adjustmet* Fuctio dip---switches Max. c.h. gas pressure adjustmet Igitio gas pressure adjustmet Boiler reset butto* *cotrol pael fascia From other boiler devices... C.h. temperature probe NTC D.h.w. temperature probe NTC D.h.w. flow switch Primary circuit flow switch Room thermostat (if fitted) Time switch Flamepresecesigal* *from the full sequece igitio device The fudametal fuctio of the Electroic startig cotrol p.c.b. is that of cotrollig the boiler i relatio to the exteral eeds (i.e. heatig the dwellig or heatig the water for d.h.w. use) ad operatig i order to keep the temperature of the hydraulic circuits costat. This is obviously possible withi the useful power ad maximum workig temperature limits foresee. Geerally, the Electroic startig cotrol p.c.b. receives ilet iformatio comig from the boiler (the sesors) or from the outside (kobs, room thermostat, etc.), processes it ad cosequetly acts with outlet commads o other compoets of the boiler (Fig. 27). 9.2 Selectio ad adjustmet devices O the Electroic startig cotrol p.c.b. several selectio, adjustmet ad protectio devices are located. (Fig. 28). Some of these devices are directly accessible by the user (fuctio cotrol, temperature adjustmet potetiometers etc.) others are accessible by removig the service pael or the cotrol pael lid Fig. 27 Outlet commad Pump Three way diverter valve Full sequece igitio device Modulatio operator Appliace operatio light* Operatio/service lamps Lock --- out sigal lamp* *cotrol pael fascia Fig Coector J1 electric supply termial block 2 Fuse F1 (3,15A V) 3 Coector J3 (Pomp, three way diverter valve) 4 Coector J16 (Modulatig gas valve) 5 Coector J19 (Flame detectio electrode) 6 Coector J15 (Fa, Air pressure switch, Safety thermostat) 7 Coector J20 e J21 (Igitio electrodes) 8 Lock--- out sigal lamp 9 Boiler reset butto 10 Fuctio cotrol / C.h. temperature adjustmet 11 Coector J7 15

18 Electroic startig cotrol p.c.b. 12 D.h.w. temperature adjustmet 13 Dip---switch selectors 14 Operatio lamps 15 Igitio gas pressure adjustmet (ACC.) 16 Maximum c.h. gas pressure adjustmet (RISC.) Whe the boiler fuctios i d.h.w. (Fig. 30), the sigal comig from the d.h.w. temperature probe is compared with the sigal give by the cotrol pael through the adjustmet made by the user (kob ). 9.3 Checkig the temperature The Electroic startig cotrol p.c.b. makes it possible to separately adjust the c.h. water flow temperature ad d.h.w. outlet temperature. The temperature of the water is coverted ito a electric sigal by meas of temperature probes. The user, settig the desired temperature with the cotrol pael kobs operates the variable elemets (10 ad 12 i Fig. 28) of the electroic cotrol p.c.b. If the power requested is lower tha 40% of the maximum power output the cotrol is achieved by switchig ON the burer at miimum power, the switchig OFF (ON/OFF fuctio). If the power requested is higher, the the burer is switched ON at maximum power ad will cotrol by modulatig to 40% of the maximum power output. Durig the c.h. operatio (Fig. 29), the sigal comig from the c.h. temperature probe is compared to the sigal give by the cotrol pael through the adjustmet made by the user (kob ). The result of such a compariso operates the modulatio of the gas valve, cosequetly chagig the useful output of the boiler. 75 ûc Fig. 30 Normally, the result of the compariso betwee these two sigals directly operates the adjustmet elemets of the gas valve modulatio device, adjustig the useful output geerated i order to stabilize the temperature of the exitig water. If durig the d.h.w. mode operatio, the temperature of the primary circuit goes over 75 C, the useful output is automatically reduced so that the primary circuit caot reach excessive temperatures. Fig The cotrol sequeces i fuctio ad i fuctio are illustrated i detail i sectios 9.11 ad Operatio lights The Electroic startig cotrol p.c.b. is provided with three lamps (L.E.D. idicators) 14 i Fig. 28 that give optical iformatio durig the ormal operatio of the boiler or for service purpose. f Normal operatio Oly the gree lamp o the left is directly visible o the cotrol pael fascia ad it gives iformatio durig the ormal operatio of the boiler. The other two lamps are ormally switched off. The followig table gives the relatioship betwee the visible lamp idicatio ad its meaig.

19 Electroic startig cotrol p.c.b. A short pulse every 4 secods Boiler i stad--- by coditio. (fuctio cotrol i positio). Ati--- freeze system active. Normally operatig boiler (see the previous table for details) C.h. operatio f 1secodON1secodOFF Very fast pulses (4 per secod) Service operatio Boiler ON coditio (fuctio cotrol i positio) or Faulty boiler or irregular operatio as: --- Empty primary circuit --- No primary circuit flow --- Lack of burer igitio --- Excessive temperature i the primary circuit. --- Dip --- switch 3 left i the OFF positio --- Faulty temperature probe With the boiler switched ON ( or ), by movig ad re---settig to its origial positio ay of the fuctio selectors 13 (Fig. 28), the Electroic startig cotrol p.c.b. goes ito service operatio mode ad all the lamps (14 i Fig. 28) are the activated. To reset the Electroic startig cotrol p.c.b. to the ormal operatio it is ecessary to tur the kob to the positio or switch off the boiler for a short while at the fused spur isolatio switch. The followig table gives the relatioship betwee each of the possible lamp combiatios ad their meaig. Lamp OFF Lamp ON D.h.w. operatio Frost protect operatio D.h.w. operatio Excessive temperature o primary circuit Faulty c.h. temperature probe NTC Faulty d.h.w temperature probe NTC Faulty primary circuit (o water or absece of flow) Lack of burer igitio (o igitio sigal from the full seqece igitio device) Igitio gas pressure adjustmet Miimum gas pressure adjustmet Lack of power supply or fauly electroic cotrol p.c.b. * Fauly electroic cotrol p.c.b. * Flashig lamp, aloe or simultaeously with a other lamp. Flashig lamp, alterate with aother lamp. * These coditios are ormal oly for a short time whe the power supply is applied to the boiler. If permaet they idicate a faulty p.c.b. 9.5 Dip---switch selectors The fuctio selectors 13 (Fig. 28 ad Fig. 31) are microswitches with which it is possible to select the various boiler cotrol fuctio modes. I Fig. 31 the selectors are illustrated i the cofiguratio i which the boiler is set i the factory (atural gas boiler). Miimum gas pressure adjustmet Gas coversio Igitio gas pressure adjustmet Reigitio frequecy ON (1) 13 OFF (0) Fig. 31 f Selector 1 This forces the boiler to operate at the miimum gas pressure i order to allow the adjustmet of the miimum gas pressure at the burer (o the modulatio operator of the gas valve). 17

20 Electroic startig cotrol p.c.b. After ay adjustmet operatio the selector has to be brought back to the ormal positio (ON). f Selector 2 This selects the boiler fuctios o the basis of the type of gas used. It allows the selectio of the maximum supply curret give to the modulator device. To set selector 2 correctly follow the table i Fig. 32. Gas supply Positio of selector Approx. Max curret through the modulator device Natural gas O 120 ma L.P.G. Off 165 ma Fig. 32 f Selector 3 This forces the fuctioig of the boiler i order to allow the optimal gas pressure at the burer to be adjusted durig the igitio phase. The adjustmet (see sectio 9.7) is doe by meas of the potetiometer 15 marked ACC (Fig. 28 o page 15). After the adjustmet operatios brig the selector back to the ormal positio (ON). OFF (0) gas pressure calibratio Fig ON (1) Normal f Selector 4 This allows you to select the miimum time that must pass betwee two igitios of the burer i c.h. fuctio. Fig. 34 ON (1) OFF (0) 30 sec. 3 mi. 9.6 Settig jumpers Two settig jumpers are fitted o the Electroic startig cotrol p.c.b. Refer to Fig. 35 for the positio of the jumpers whe the Electroic startig cotrol p.c.b. is fitted o a M90F.24S M90F.28S or M90F.32S boiler. Refer to Fig. 36 whe the Electroic startig cotrol p.c.b. is fitted o a M90F.24SR or M90F.28SR boiler. The umbers refer to the markig prited o the circuit board. Fig Fig Igitio gas pressure adjustmet By usig the device 15 (Fig. 28) marked ACC. o the Electroic startig cotrol p.c.b., it is possible to adjust the gas pressure at the ijectors i the igitio phase. This pressure is maitaied at the ijectors util igitio occurs (ioizatio sigal from the full sequece igitio device). To carry out the adjustmet move the fuctio selector 3 to the OFF positio (Fig. 33) ad use the adjustmet device 15 (ACC). Adjust the gas pressure at the ijectors to the value idicated i the tables of the User/Istallatio maual (Techical iformatio sectio, Gas pressures at the burer table). By rotatig the device clockwise the pressure icreases. Check the regular igitio of the burer by turig the boiler o ad off repeatedly. After the adjustmet operatios brig the selector 3 back to the ormal positio (ON). 9.8 Max c.h. power adjustmet By usig device 16 (Fig. 28) marked RISC. o the Electroic startig cotrol p.c.b., you ca limit the maximum useful output delivered durig the c.h. operatig mode. This adjustmet does ot ifluece the maximum useful output delivered durig the d.h.w. operatig mode. By rotatig the device clockwise the pressure icreases. 9.9 Checks Check that the fuse is complete If the Electroic startig cotrol p.c.b. does ot supply ay device (pump, fa, etc.) check that the fuse 2 (Fig. 28) is complete. If the fuse has blow replace it with oe that has the same characteristics after havig idetified the reaso for failure. Check the settig jumpers positio Two settig jumpers must be fitted o the Electroic startig cotrol p.c.b. as show i Fig Removal of the electroic cotrol p.c.b 1 Gai access to the parts located iside the cotrol pael as explaied i the sectio 2.3 of this maual. 2 Remove all the wirig coected to the Electroic startig cotrol p.c.b..

21 Electroic startig cotrol p.c.b. To discoect the coectors J1, J3, J7, J15, J16 ad (5, 1, 8, 14 ad 6 i Fig. 28) delicately flex the hook preset o oe side of each socket. 3 Remove the spidles of the c.h. ad d.h.w. temperature adjustmet kobs by delicately pullig them with pliers i the directio show by the arrow i Fig While tighteig the screws that fix the Electroic startig cotrol p.c.b. o the cotrol pael, keep the p.c.b. towards the cotrol pael fascia makig sure of the cotact betwee the boiler reset butto B ad the tab C (Fig. 38). A Fig Uscrew the four screws that hold the Electroic startig cotrol p.c.b. o to the cotrol pael. 5 Remove it by liftig its rear edge ad freeig it from ay of the wirig. 6 Re---assemble the Electroic startig cotrol p.c.b. followig the removal procedures i the reverse order. Importat Whe re---assemblig the Electroic startig cotrol p.c.b.: 7 Fit the p.c.b. ito the cotrol pael by first isertig the frot lower edge uder the cotrol kob shafts. Lower the rear edge ad esure that o wirig is trapped beeath. 8 Isert the spidles i the cotrol pael kobs utill the otch A (Fig. 38) reaches the potetiometer edge. It is ot ecessary to force them i the kob. Fig. 38 Attetio A B After istallig the Electroic startig cotrol p.c.b. : 10 Make sure the c.h. ( ) ad d.h.w. ( )temperature adjustmet kobs ca move freely for thecompleterage. If ot, remove the spidle agai as described at step 3, tur the kob half a tur ad re---isert the spidle. 11 Operate the boiler ad close the gas ilet cock so that the boiler goes ito the safety lock---out state. Verify the correct operatio of the boiler reset butto by pressig ad releasig it. Warig: After cleaig or replacemet as detailed above refer to sectio Combustio aalysis check i the chapter Maiteace of the istallatio istructios maual. C 19

22 Electroic startig cotrol p.c.b Thermal cotrol i the mode See fuctioig with the fuctio cotrol i the mode (sec. 9.12) Takig water from the domestic hot water circuit? Is primary circuit temperature higher tha that selected? Circulator off Operates motorised valve Igitio device off Request for heat from room thermostat? Starts the circulator Operates motorised valve Supplies the igitio device lock memorised? cacels lock Air pressure switch at rest? starts fa Air pressure switch at work? begiig of wait period presece of flame? Air pressure switch at work? starts igitio discharges opes gas valve begiig of igitio period flame presece? ed of igitio period? closes gas valve stops fa iterrupts igitio discharges memorizes lock turs o lock--- out light iterrupts igitio discharges gas valve ope reset push --- butto pressed? closes gas valve flame presece? Safety thermostat opes the circuit? Air pressure switch at work? Fig

23 Electroic startig cotrol p.c.b Thermal cotrol i the mode Switch i the fuctio mode Circulator o Takig water from the domestic hot water circuit? Circulator off Igitio device off Is domestic hot water outlet temperature lower tha that required? Igitio device off lock memorised? cacels lock Air pressure switch at rest? starts fa Air pressure switch at work? begiig of wait period presece of flame? Air pressure switch at work? starts igitio discharges opes gas valve begiig of igitio period flame presece? ed of igitio period? closes gas valve stops fa iterrupts igitio discharges memorizes lock turs o lock--- out light iterrupts igitio discharges gas valve ope reset push --- butto pressed? closes gas valve flame presece? Safety thermostat opes the circuit? Air pressure switch at work? Fig

24 10 Modulatig gas valve 10.1 Fuctio The Modulatig gas valve A i Fig. 41 cotrols the gas iflow to the boiler burer Fig Adjustmet 22 A Fig. 41 By meas of a electric commad give to the o---off operators the passage of the gas through the Modulatig gas valve ca be opeed or closed. By meas of a electric commad give to the modulatio operator the pressure ca be varied ad therefore the gas flow rate to the burer (modulatio). The modulatio operator has mechaical compoets which allow the adjustmet of the miimum ad maximum pressure exitig the valve Nomeclature of the parts (Fig. 42) 1 Modulatio operator s electric coectors 2 Miimum gas pressure adjustmet 3 O---off operators 4 Maximum gas pressure adjustmet 5 O---off operators electric coector 6 Gas valve ilet pressure test poit 7 Modulatio operator 8 Gas valve outlet pressure test poit 1 Remove the frot pael of the case. 2 Ope the gas valve ilet pressure test poit (6 i Fig. 42) at the valve iput, coect a suitable pressure gauge ad check the gas pressure of the supply etwork. 3 Remove the gauge ad close the pressure test poit 6. 4 Ope the gas valve outlet pressure test poit (8 i Fig. 42) ad coect the gauge; 5 Remove the protectio cap from the mechaical pressure adjustmet compoets; 6 Start the boiler at its maximum power. Operate the boiler i d.h.w. mode or esure that theboilerisotrageratedifthetestiscarriedout i c.h. mode. 7 Rotate the maximum gas pressure adjustmet (4 i Fig. 42) util you obtai the required pressure (by rotatig clockwise the pressure icreases). 8 Discoect oe of the two coectors (1 i Fig. 42) or, alteratively, remove the service pael as explaied i the sectio 2.3 of this maual ad set the dip---switch selector 1 (see sectio 9.5) to the OFF positio. 9 Rotate the miimum gas pressure adjustmet (2 i Fig. 42) util you obtai the required pressure (by rotatig clockwise the pressure icreases). 10 Tur the boiler off ad re---coect the wire to the modulatig operator (or set the dip--- switch selector 1 back to the ON positio). 11 Start the boiler ad check agai the maximum gas pressure settig. 12 Tur the boiler off ad discoect the gauge. Importat: after the gas pressure checks ad ay adjustmet operatios, all of the test poits must be sealed.

25 Modulatig gas valve 10.4 Checks Check the modulatio operator coil 1 Remove the frot pael of the case. 2 Discoect the coectors B (Fig. 45) from the modulatig operator ad measure the electrical resistace of the coil. Its electrical resistace valuemustbeapprox.80ω*. Check the o--- off operators coils 1 Remove the frot pael of the case. 2 Discoect the electrical coector C (Fig. 45). 3 Measure the electrical resistace betwee the coector pis of the o--- off operators as illustrated i Fig. 43. Upper o---off operator approx Ω* Lower o --- off operator approx. 920 Ω* 10.6 Removal of the gas valve 1 Remove the frot pael of the case as explaied i the sectio 2.3 of this maual. 2 Discoect the coectors B ad C (Fig. 45). 3 Tur off the gas supply ad discoect the gas isolatio cock coector from the ilet port of the gas valve. 4 Uscrew the coectors F ad remove the pipe G 5 Uscrew the screws H ad remove the valve. 6 Reassemble the valve carryig out the removal operatios i reverse order. After ay service operatio o the compoets of the gas circuit check all the coectios for gas leaks. * at ambiet temperature. Fig Removal of the o--- off operators coils 1 Remove the frot pael of the case as explaied i the sectio 2.3 of this maual. 2 Discoect the coector D (Fig. 44). 3 Uscrew the screw E ad remove o---off operator coils. 4 Reassemble the coils carryig out the removal operatios i reverse order. Warig: After cleaig or replacemet as detailed above refer to sectio Combustio aalysis check i the chapter Maiteace of the istallatio istructios maual. F G B C H D E Fig. 45 Fig

26 11 Primary circuit flow switch 11.1 Fuctio The Primary circuit flow switch (A i Fig. 46) fuctio is to detect water flowrate through the primary hydraulic circuit of the boiler Checks Mechaical fuctio 1 Remove the frot pael of the case. 2 Start ad stop the boiler either i d.h.w. or c.h. mode. 3 Lookig through the switch box verify the positio of the shaft B referrig to Fig. 48. Boiler OFF Fig. 48 B Boiler ON I A Electrical check It is possible to verify the geeral operatio of the switch by measurig the electric resistace betwee the cotacts C. ad N.O. of the switch. 1 Remove the switch as explaied i sectio Measure the electrical resistace betwee the tabs marked C. ad N.O. (Fig. 49). The cotact must be ormally ope. 3 Operate the switch by had ad verify that the cotact is ow closed. C Fig. 46 This hydraulic/membrae operated electrical micro--- switch device will cotrol the fuctioig of the igitio cotrol circuit, providig there is a adequate quatity ad flow of water i the primary circuit. Ay failure of the pump or obstructios i the primary circuit, whilst i either c.h. or d.h.w. modes, will ot allow the device to operate. This device is coected to the electroic cotrol p.c.b. ad if, after the pump operates, it does ot activate withi 20 secods the cotrol board will idicate that a fault coditio (see sectio 9.4 of this maual) has occurred. Fig. 47 D C Fig. 49 N.O Removal do ot use Removal of the switch 1 Remove the frot ad right had side paels of the case. 2 Remove the fork C (Fig. 47). 3 Ope the box ad discoect the switch. 4 Re---assemble the parts i reverse order of removal. Refer to Fig. 49 for the correct wirig coectors o the switch Removal of the membrae 1 Remove the frot ad right had side paels of the case, tur off the flow ad retur isolatio valves ad empty the primary circuit. 2 Remove the fork C that holds the micro---switch housig D (Fig. 47). 3 Uscrew the four screws E (see Fig. 50) ope the hydraulic operator ad remove the membrae F. 24

27 H Fig Reassemble the parts i reverse order of removal. Whe assemblig the membrae, esure that its cocave side faces towards the actuator plate G ad the referece idicated aligs with the seat H (see Fig. 50). F G E 1 Remove the frot ad left had side paels of the case, tur off the flow ad retur isolatio valves ad empty the primary circuit. 2 Completely uscrew the coectio K, thelockut L (Fig. 52) ad remove the expasio vessel from the top of the boiler. L K 12 Expasio vessel ad temperature---pressure gauge 12.1 Fuctio The Expasio vessel (I i Fig. 46) fuctio is to allow for the volume expasio of the c.h. circuit water due to the temperature rise Checks 1 Tur off the flow ad retur isolatio valves ad empty the primary circuit of the boiler. 2 Remove the protective cap J (Fig. 51) from the valve o the top of the expasio vessel ad coect a suitable air pressure gauge. J Fig Re---assemble the parts i reverse order of removal Removal of the temperature---pressure gauge 1 Remove the frot ad right had side paels of the case, tur off the flow ad retur isolatio valves ad empty the primary circuit. 2 Remove the fork M ad the probe holder sprig N (Fig. 53). 3 Squeeze the tabs O to release the temperature--- pressure gauge P ad remove it. 4 Re---assemble the parts i reverse order of removal. Fig Check the pre---load pressure ad refer to the sectio Expasio vessel i the User maual ad istallatio istructios for the correct value. P O 12.3 Removal of the expasio vessel If there is at least 400 mm clearace above the boiler ad the rear exit flue ca be easily removed, the expasio vessel ca be chaged without removig the boiler. Fig. 53 M N 25

28 13 D.h.w. flow switch, filter ad flow limiter 13.1 Fuctio The d.h.w. flow switch A i Fig. 54 is a device that geerates a electrical sigal whe hot water is draw Nomeclature ad locatio of parts (Fig. 56) 1 Flow switch sesor 2 Body 3 O --- rig 4 Sprig 5 Magetic rig 6 Float 7 Threaded rig 8 Flow limiter (optioal accessory) 9 Filter 10 Sprig seat 1 A Fig. 54 Whetheflowratethroughthed.h.w.circuitreaches about 2,5 litres/mi, the float 6 (Fig. 56) is draw towards the right. The resultig magetic field of rig 5 icreases ad reaches the flow switch sesor 1. The sesor geerates a electrical sigal that switches the boiler d.h.w operatio ON. The state of the sesor is also idicated by meas of the lamp B placed o the sesor body. Fig Checks B C Flow switch sesor operatio 1 Remove the frot pael of the case. 2 Switch o the boiler ad ope a d.h.w. tap. The lamp B (Fig. 55) placed o the sesor body is switched o whe the flow rate reaches about 2,5 litres/mi Removal of the flow switch sesor Fig Remove the frot pael of the case. 2 Discoect the coector C (Fig. 55) ad remove the sesor by delicately liverig dowwards with a screwdriver.

29 D.h.w. flow switch, filter ad flow limiter 13.5 Removal of the flow switch group ad d.h.w. circuit filter 1 Remove the frot pael of the case ad empty the d.h.w. circuit. 2 Remove the flow switch sesor (see sectio 13.4). 3 Uscrew the body 2(Fig. 56) ad extract the flow switch group. 4 To remove the filter from the flow switch group separate the filter 9 from the threaded rig (Fig. 56) by leverig it. 5 Reassemble the parts followig the removig sequece i reverse order Flow limiter The M90F.24S model is factory fitted with a 10 litre/mi. flow limiter. If o the M90F.28S model the flow rate of the d.h.w. circuit is too high, it is possible to limit it by istallig a flow limiter. The followig sizes are available: Nomial flow rate (litres/mi) Colour 10 Yellow 12 Brow To istall the threaded rig with the flow limiter: 1 Remove the flow switch group as explaied i the sectio Remove the filter from the flow switch group. 3 Uscrew the threaded rig 7 (Fig. 56) ad remove it from the body 2. 4 Reassemble the group followig the above sequece i reverse order. 27

30 14 Temperature probe 14.1 Fuctio The Temperature probe has the fuctio of covertig the temperature of the water i the hydraulic circuit where it is istalled ito a electrical sigal (resistace). The relatio betwee temperature ad electrical resistace is stated i Fig. 57. Ω Fig O the boiler there are two Temperature probes. Oe o the output of the primary heat exchager (c.h. Temperature probe) A i Fig. 58 ad Fig. 59; oe o its iput, before the pump (d.h.w. Temperature probe) B i Fig. 58 ad Fig. 60. ûc 14.2 Checks Temperature---resistace relatioship Discoect the cable from the Temperature probe. Measure the temperature of the brass group where the Temperature probe is located ad check the electrical resistace accordig to the graph i Fig Removal Refer to Fig. 59 for the c.h. Temperature probe ad to Fig. 60 for the d.h.w. Temperature probe. 1 To remove the Temperature probes remove the frotadrighthadsidepaelsofthecase. 2 Empty the primary circuit of the boiler. 3 Remove the electric coector of the Temperature probe ad uscrew it. 4 Reassemble the Temperature probe carryig out the removal operatios i reverse order. A Fig. 59 A B B Fig c.h. retur c.h. flow d.h.w. ilet d.h.w. outlet Fig. 60

31 15 By --- pass valve 15.1 Fuctio The By --- pass valve A i Fig. 61 is located betwee the c.h. water flow ad retur ad its fuctio is that of guarateeig a miimum flow across the primary heat exchager if the circulatio across the c.h. system is completely closed. TheBy---passvalveisfittedotherearsideofthediverter group Removal 1 Removeallthecasepaels. 2 Empty the primary circuit of the boiler. 3 Remove the diverter group as described i the sectio 8.4 of this maual. 4 Uscrew the coector B ad remove the by --- pass valve C (Fig. 62). B C Fig. 61 A Fig Reassemble the by--- pass valve as illustrated i Fig. 62 reversig the order of removal. 29

32 16 Igitio ad detectio electrodes 16.1 Fuctio Three electrodes are fitted ear the frot part of the burer. The igitio sparks take place betwee the metallic edges of the igitio electrodes over the cetral ramp of the burer durig the igitio sequece. The third electrode is the detectio electrode ad it detects the presece of the flame. Fig. 63 shows the electrodes cofiguratio o the models M90F.24S, M90F.24SR, M90F.28S, M90F.28SR. Fig. 64 shows the electrodes cofiguratio o the model M90F.32S Detectio 16.2 Checks Check the positio of the electrode edges 1 Remove all the case paels, the sealed chamber lid ad the combustio chamber lid. 2 Check for the correct distace betwee the metallic edges of the igitio electrodes (see Fig. 65). Igitio 4mm Igitio Male Female Fig Check the itegrity of the detectio electrode ad esure that its metallic edge is correctly placed over the ramp of the burer. Check the coectio wires. Fig. 63 Detectio Male Female Fig Igitio 1 Remove all the case paels, the sealed chamber lid ad the combustio chamber lid. 2 Check for the itegrity of the isulatio of wires which coect the electrodes to the igitio device Removal 1 Remove all the case paels, the sealed chamber lid ad the combustio chamber lid. 2 Discoect the electrode wires from the full sequece igitio device. 3 Remove the burer by uscrewig the four screws placed at the right ad left sides of the burer. 3b For models M90F.28S, M90F.28SR ad M90F.32S remove also the plate C (see Fig. 68 o page 32). 4 Uscrew the screws A (Fig. 66) which hold the electrodes to the burer. Two screws are used o the models M90F.24S, M90F.24SR, M90F.28S, M90F.28SR. Three screws, oe for each electrode, are used o the model M90F.32S.

33 Igitio ad detectio electrodes 5 Extract the electrodes from the burer. 6 Assemble the electrodes carryig out the removal operatio i reverse order. Refer to Fig. 63 i order to recogise the electrodes ad to correctly coect the wirig. Note: the metallic edge of the detectio electrode is loger tha the oe of the igitio electrodes. Warig: After cleaig or replacemet as detailed above refer to sectio Combustio aalysis check i the chapter Maiteace of the istallatio istructios maual. A Fig

34 17 Safety thermostat 17.1 Fuctio The safety thermostat A i Fig. 67 is a device that seses the temperature of the primary circuit water which flows i the outlet pipe of the primary heat exchager. If the temperature cotrol system of the boiler fails ad the temperature of the primary circuit reaches a dagerous temperature, the safety thermostat opes the electric circuit that supplies the o---off operators of the gas valve. Cosequetly, the full sequece igitio device attempts to light the burer ad, at the ed, locks the boiler ad lights the lock---out sigal lamp. cotact must be closed (electrical resistace zero Ω) Removal 1 Removeallthecasepaelsadthelidofthe sealed chamber. 1b For models M90F.28S ad M90F.28SR, remove the screw B ad the plate C (Fig. 68). A C B Fig Discoect the wirig D (Fig. 69). 3 Remove the sprig E which holds the overheat thermostat o the pipe of the primary heat exchager ad remove it. D Fig. 67 E 17.2 Checks Overheat temperature value 1 Set the temperature cotrol kobs to their max. positio ad ru the boiler i d.h.w. ad c.h. 2 Allow the boiler to reach its maximum operatig temperature (moitor the temperature gauge o the istrumet pael). The boiler should maitai a temperature below that of the safety thermostat ad o overheat itervetio should occur. Electrical fuctio 1 Removeallthecasepaelsadthelidofthe sealed chamber. 2 Discoect the safety thermostat ad check its electrical fuctio. Normally (o itervetio) the 32 Fig Reassemble the overheat thermostat carryig out the operatios i reverse order. 5 Apply a adequate quatity of heat coductig compoud betwee the pipe ad the thermostat. Warig: After cleaig or replacemet as detailed above refer to sectio Combustio aalysis check i the chapter Maiteace of the istallatio istructios maual.

35 18 Short spare parts list Key G.C. part o. Descriptio Q.ty Maufacturer Maufacturer s referece part o Burer (mod. M90F.24S, M90F.24SR) 1 KI Polidoro Burer (mod. M90F.28S, M90F.28SR) 1 KI Burer (mod. M90F.32S) 1 BI Ijectors for atural gas 12 KI Polidoro (mod. M90F.24S, M90F.24SR) Ijectors for atural gas 14 (mod. M90F.28S, M90F.28SR) Ijectors for atural gas (M90F.32S) 16 BI Ijectors for LPG (mod. M90F.24S, M90F.24SR) 12 KI Ijectors for LPG (mod. M90F.28S, M90F.28SR) 14 3 E Expasio vessel 1 BI CIMM 6 litres 4 Mai heat exchager (mod. M90F.24S, 1 BI M90F.24SR) Mai heat exchager (mod. M90F.28S, 1 BI M90F.28SR) Mai heat exchager (mod. M90F.32S) 1 BI Fa (mod. M90F.24S, M90F.24SR) 1 BI FIME GR W Fa (mod. M90F.28S, M90F.28SR) 1 BI FIME GR W Fa (mod. M90F.32S) 1 BI FIME GR W 6 E Gas valve 1 BI SIT 845 Sigma Air pressure switch 0,88---0,74 mbar 1 KI Yamatake---Hoeywell C6065 (mod. M90F.24S, M90F.24SR) Air pressure switch 1,04---0,92 mbar 1 BI SIT 380 (alterative) (mod. M90F.28S, M90F.28SR Air pressure switch 1,38---1,25 mbar 1 BI (mod. M90F.32S) 8 E Safety valve 1 BI Watts Orkly (alterative) 9 E Combustio chamber side paels 2 BI E Combustiochamberrearpael 1 BI (mod. M90F.24S, M90F.24SR) E Combustiochamberrearpael 1 BI (mod. M90F.28S, M90F.28SR, M90F.32S) 11 E Combustio chamber frot pael 1 BI (mod. M90F.24S, M90F.24SR) E Combustio chamber frot pael 1 BI (mod. M90F.28S, M90F.28SR, M90F.32S) 12 Electroic regulatio p.c.b. 1 BI E Full sequece igitio device 1 BI Bertelli & Parters FM30 Hoeywell FPLD (alterative) 14 E D.h.w. heat exchager (mod. M90F.24S,) 1 BI E D.h.w. heat exchager 1 BI (mod. M90F.28S, M90F.32S) 15 Pump 1 BI WSC --- NFSL 12/5 16 E Primary circuit flow switch 1 BI E D.h.w. flow switch 1 BI E Mai. flow switch membrae 1 BI E Three way diverter valve (electric actuator) 1 BI Elbi 20 E Overheat thermostat 1 BI ELTH --- type Fuse 1,6 A T 1 BI Temperature probe (mai or d.h.w. circuit) 1 BI E Igitio electrode --- left (mod. M90F.24S, 1 BI M90F.24SR, M90F.28S, M90F.28SR) Igitio electrode --- left (mod. M90F.32S) 1 BI E Igitio electrode --- right (mod. M90F.24S, 1 BI M90F.24SR, M90F.28S, M90F.28SR) Igitio electrode --- right (mod. M90F.32S) 1 BI