SEDBUK Band A Gas Condensing Boilers. The Greenstar range of high efficiency gas condensing boilers from Worcester

SEDBUK Band A Gas Condensing Boilers The Greenstar range of high efficiency gas condensing boilers from Worcester

heating & hot water comfort Britain s switching to new hig The reasons why, the benefits of high efficiency boilers and how to choo To the majority of people in Britain, heating and hot water are basic everyday comforts we take for granted. We turn on a tap or shower, turn up the thermostat on a chilly evening and settle down to watch the TV. But there is a cost to the environment. The waste gases discharged through the flues of domestic central heating boilers account for about 21%* of the UK s total emissions of carbon dioxide, which globally is a major contributor to climate change. Now the Government has acted to try and address the problem. Changes to Building Regulations mean that from 1st April 2005, the only kind of boiler permitted in all new and virtually all replacement domestic installations will be the high efficiency condensing type. Which, as you will discover by reading on, is very good news for everyone who enjoys the luxury of convenient heating and hot water but who is also concerned about saving money, conserving non-renewable energy resources and helping the environment. So whether you re thinking seriously of investing in a complete new central heating system, or simply replacing an old boiler, this practical guide from Worcester Bosch will give you the answers to many very important questions. * Source: Energy Saving Trust, 2005. 2

efficiency boilers e the one that s best for you and your home What do the changes to Building Regulations require? Changes to Building Regulations for England and Wales, effective from 1st April 2005, stipulate that: With very few exceptions, all new domestic gas boilers installed must be high-efficiency condensing boilers, rated A or B on the SEDBUK scale. (This is a measure of a boiler s energy efficiency in the same way that fridges, washing machines and other appliances are rated and labelled according to their energy usage. See the SEDBUK table on page 5.) All new gas boiler installations must also satisfy the new minimum requirements for heating controls (as explained on page 20). All installers fitting these boilers must be CORGI registered, and trained and qualified in energy efficiency and the new condensing boiler Building Regulations. After completion of your new boiler installation, you will receive a certificate from your local authority confirming that the boiler complies with the new Building Regulations. This document will be important should you ever decide to sell your house. Only where it is not feasible to install a condensing boiler can an installer recommend an alternative type of boiler which can be legally fitted instead. Contents Page What is a high-efficiency condensing boiler? 4 What type of condensing boiler is best for me? 6 What are the benefits of choosing Worcester Bosch? 10-11 Greenstar condensing combi boilers 12-16 Greenstar condensing system boilers 17 Greenstar condensing regular boilers 18-19 What controls options are offered by Worcester Bosch 20-22 The Technology Guide 23-26 Greenstar condensing boiler range specification & features 27 3

heating & hot water comfort What is a high-efficiency cond A high-efficiency condensing boiler is by far the most efficient and economical boiler money can buy. Choose wisely and it will prove to be an investment, not an expense. The term condensing is derived from the the creation of condensation within the boiler or flue system, which is a natural process when combustion of any kind takes place. A condensing boiler is more efficient due to its ability to extract more heat from the gas used. Perhaps the term high efficiency in is best summed up by this staggering fact: if every home in the UK installed a high-efficiency condensing boiler, the money saved would cover the cost of the annual fuel and power bills of more than two million households.* The Worcester Bosch Greenstar condensing boilers detailed in this guide are all rated in SEDBUK Band A the highest efficiency band achievable. They are more than 90% efficient which in simple terms means that over 90% of the gas consumed when the burner is firing is converted into heat for your heating and hot water system. So there s very little energy wastage, resulting in very economical running costs and lower bills. You need less gas or oil to achieve the same heat so they simply make sense. By comparison, many older boilers in use around the UK operate at as low as 50% efficiency that s 50p of every pound of your fuel bill disappearing up the chimney does that make sense? No it doesn t, and that s why the Government is acting to stop it. Many others are hovering around 70-75% efficiency, but that s still a quarter of your bill that is wasted. The good news is that replacing an old boiler with a new high-efficiency condensing boiler could give you immediate savings of around 30% on your heating bills.* How is this high efficiency achieved? Like most good ideas, it s very simple. Unlike all other types of boiler, which allow heat to escape wastefully up the flue, a condensing boiler saves and uses this heat for your benefit. It does this by means of a larger or second heat exchanger (as explained in more detail in the Technology Guide on page 23). This not only increases boiler efficiency dramatically but also reduces emissions of both CO 2 (Carbon Dioxide) and NOx (Nitrogen Oxide) to extremely low levels good news in the battle to combat global warming and address climate change. What types of fuel are high-efficiency condensing boilers suitable for? This guide is concerned specifically with gas-fired boilers, but all the benefits of condensing boiler technology apply equally to high-efficiency boilers fuelled by LPG (liquid petroleum gas) or oil. * Source: Energy Saving Trust, 2005. 4

ensing boiler? Is there an ideal time to install a new high-efficiency condensing boiler? There s never a bad time to cut your fuel bills! However, normally, new boilers are installed in a home for one of two main reasons: as part of a brand new central heating and hot water system, or to replace an old boiler which is either inefficient or prone to costly breakdowns. If you happen to be in the process of improving your kitchen or bathroom, it makes good sense to consider fitting a new high efficiency condensing boiler at the same time. This way you will reap all of the benefits and at minimal cost and disruption. What are SEDBUK ratings? Seasonal Efficiency of Domestic Boilers in the UK is the method developed under the Government s Energy Efficiency Best Practice Programme with the co-operation of boiler manufacturers and provides a basis for fair comparison of different models. SEDBUK is the average annual efficiency achieved in typical domestic conditions, making reasonable assumptions about pattern of usage, climate, control and other influences. Central heating boilers now come with an energy label, as do many white goods appliances your fridge, your washing machine etc. The new Building Regulations stipulate that only condensing boilers rated in Band A or Band B (A being the highest and most efficient) can be installed after 1st April 2005. If your home currently has a central heating boiler with a SEDBUK rating label, this table will enable you to compare it with a Band A or Band B high-efficiency condensing boiler. 5

heating & hot water comfort What type of condensing boi There are 3 different types of high-efficiency condensing boiler combi, system and regular (which is also often referred to as a traditional or conventional boiler regular, traditional and conventional, all effectively mean the same). Each type delivers all the benefits of high-efficiency technology, but which one you choose will depend on several factors, including your property, your lifestyle and the professional advice of your CORGI registered installer. For example, the heating and hot requirements of a large family home with two or more bathrooms will differ considerably from those of an apartment or bungalow. Here are a few examples and guidelines to think about and help you identify the type of boiler most likely suited to your needs. Consideration You want to use your loft space for a room conversion or other purpose You live in a flat or bungalow (i.e. have very little or no roofspace) Your home has more than 2 bathrooms Your mains water pressure is low You want to replace an old boiler to improve an existing conventional central heating system The number of people in your household means that there is regular demand for hot water on tap, but waiting for the tank to constantly refill and heat up is, or would be, inconvenient 6 Most suitable boiler COMBI COMBI REGULAR OR SYSTEM REGULAR OR SYSTEM REGULAR, SYSTEM OR COMBI COMBI

er is for me? What is a combi boiler? The high-efficiency condensing combi (or combination) boiler is an ingenious space-saving idea, and an increasingly popular choice in UK homes. In fact, combis now account for well over half of all the new domestic boilers installed in Britain every year. The major difference between a combi and any other type of boiler is that a combi eliminates the need to store hot water so no hot water cylinder in the airing cupboard. It is both a highefficiency water heater and central heating boiler, combined (hence the name) within one compact unit which usually sits in the kitchen or utility room, or sometimes in the airing cupboard. The space savings result from the fact there is no hot water storage cylinder, cold water storage cistern or other familiar components of a regular (conventional) heating system. Combis offer excellent power showering The further benefits of this are a significant saving on hot water costs, and the fact that hot water is delivered through your taps or shower at mains pressure. So you can enjoy power showering* without the need for a pump. Another combi benefit is that it can generally save you money on installation time and costs no tanks in the roof space means less pipework and a shorter installation time. * A thermostatically-controlled shower safeguards against sudden changes in water temperature. 7

heating & hot water comfort What is a system boiler? Unlike a combi, both a system boiler and a regular (conventional) boiler work on the principle of stored hot water but a system boiler differs from a regular boiler in two important respects. Firstly, many of the major individual components of the heating and hot water system are built in, which means that installation is quicker, neater, easier and less costly. Secondly, the hot water is pumped from the boiler through the system to the radiators and hot water cylinder, resulting in fast response and more economical running costs. 8

How do the different system layouts compare? The regular boiler system layout Cold Water Storage Cistern Feed and Expansion Cistern Hot Water Cylinder Programmer Worcester Bosch Regular Boiler Hot to Basins and Appliances etc. Hot to Baths, Showers and Basins etc. Motorised Valve Pump Room Thermostat The combi system layout Hot to Baths, Showers and Basins W orcester Bosch Combi Boiler Room Thermostat Hot to Basins and Appliances etc. What is a regular boiler? If you re replacing an older central heating system, the chances are that it will have a regular (conventional) boiler. A typical conventional system incorporates a boiler and controls, a feed and expansion cistern, and a hot water cylinder (usually in the airing cupboard) which is fed by a cold water storage cistern located in the loft. What else should I consider when investing in a new boiler? Quality Efficiency Reliability Controllability Back-up service Long-term as well as current needs The system boiler layout System boiler with low pressure hot water cylinder Programmer Worcester Bosch System Boiler System boiler with unvented hot water cylinder Programmer Worcester Bosch System Boiler Hot Water Cylinder Hot Water Cylinder Hot to Basins and Appliances etc. Cold W ater Storage Cistern Hot to Baths, Showers and Basins etc. Motorised Valve Motorised Valves Room Thermostat Room Thermostat 9

heating & hot water comfort What are the benefits of choosing Worcest The Bosch pedigree For well over a century, Bosch has been one of the most respected names the world over for consistent quality, reliability, service and value for money. Worcester Bosch is part of the Bosch Group Heating Division, BBT Thermotechnology, which accounts for 30% of the European condensing boiler market. Advanced technology The new generation of Greenstar high-efficiency condensing boilers has evolved over many years and is the most technically advanced and efficient range ever to carry the Worcester Bosch name. Higher efficiency for lower bills The less gas you burn to produce all the heating and hot water you need, the more efficient your boiler and the lower your gas bills. All Greenstar condensing boilers carry a SEDBUK Band A energy efficiency rating the highest and are more than 90% efficient. They are also in the top rating for producing minimal emissions of Nitrogen Oxide and Carbon Dioxide. Styled for the 21st century All Worcester Bosch Greenstar boilers are designed to blend beautifully with all other modern appliances and in even the most luxurious kitchens. They are our cleanest and most sophisticated boilers ever and in sync with the needs of you and the environment. Designed and manufactured for UK homes The Worcester Bosch factory and headquarters are based at Worcester and all Greenstar boilers and associated aftersales care are geared to satisfying the specific requirements of the UK market. Innovative features All new Greenstar boilers benefit from a host of advanced features which add up to lower running costs, greater reliability and better control over your system. Some of these features are described in the Technology Guide (pages 23-26). More control options Choosing the right central heating controls to match your needs can save energy and reduce your gas bills still further. Worcester Bosch offer a variety of very practical control options, as described on pages 20-22. More fluing options Although the kitchen is often favoured as the site for a modern streamlined boiler, the flexibility of Worcester Bosch flue design opens up the possibility for you to install your Greenstar condensing boiler in the airing cupboard, garage, loft or cellar. Your local CORGI registered gas installer will advise you. 10

r Bosch? More customer services, more peace of mind From pre-sales to aftersales, Worcester Bosch can help you in all sorts of ways: For information and advice Visit the website at www.worcester-bosch.co.uk Call the helpline on 08705 266241. Warranties All Greenstar boilers carry a comprehensive 1 year warranty, extended free to 2 years on condition that you register the guarantee within 30 days of installation. There are also options to extend your cover period still further. Servicing and repairs Worcester Bosch has a nationwide network of 250 service engineers, each employed and trained directly by the company and providing an efficient, prompt and quality service. Cost-effective optional annual service contracts and boiler protection plans give further peace of mind for the life of your Worcester Bosch boiler. Installing a Worcester Bosch high-efficiency boiler Further information and advice on installing a Worcester Bosch condensing boiler is available from your local CORGI registered gas installer, whose number should be listed in Yellow Pages. Alternatively, call Worcester Bosch on 08705 266241 to be put in touch with a professional installer in your area, or visit our website at www.worcester-bosch.co.uk 11

heating & hot water comfort The Worcester Bosch Greenstar i Junior Condensing Combi Boiler Series Designed for the smaller to medium sized property, the Greenstar i Junior combi series offers built-in Worcester Bosch quality and reliability. The Greenstar 24i Junior CENTRAL HEATING OUTPUT 7.2-24kW HOT WATER FLOW RATE 9.8 LITRES PER MINUTE* SUITABLE FOR A SMALL/MEDIUM SIZED, 1 BATH FLAT, APARTMENT OR HOUSE. The Greenstar 28i Junior CENTRAL HEATING OUTPUT 7.2-28kW HOT WATER FLOW RATE 11.4 LITRES PER MINUTE* SUITABLE FOR A MEDIUM SIZED, 1 BATH FLAT, APARTMENT OR HOUSE. *At 35ºC T 12 Optional Controls A choice of optional controls is available. Mechanical Timer Mechanical RF Thermostat Digistat Programmable Room Thermostat Twin Channel Digital Programmer RF Thermostat with Twin Channel Digital Programmer

The Worcester Bosch Greenstar Si Condensing Combi Boiler Series Greenstar Si series combi boilers offer compact dimensions and a wide choice of optional controls for maximum heating and hot water comfort. Optional Controls A choice of optional controls is available. The Greenstar 25Si CENTRAL HEATING OUTPUT 7.2-25kW HOT WATER FLOW RATE 10.2 LITRES PER MINUTE* SUITABLE FOR A SMALL/MEDIUM SIZED, 1 BATH FLAT, APARTMENT OR HOUSE. The Greenstar 30Si CENTRAL HEATING OUTPUT 7.2-30kW HOT WATER FLOW RATE 12.3 LITRES PER MINUTE* SUITABLE FOR A MEDIUM SIZED, 1 BATH FLAT, APARTMENT OR HOUSE. Mechanical Timer Twin Channel Digital Programmer Mechanical RF Thermostat RF Thermostat with Twin Channel Digital Programmer Digistat Programmable Room Thermostat Optimising Digistat Controller 7 Day Programmable Room Thermostat *At 35ºC T 13

heating & hot water comfort The Worcester Bosch Greenstar CDi Condensing Combi Boiler Series With four heating and hot water outputs from which to choose, the Greenstar CDi series can satisfy the heating and hot water requirements of a wide range of homes. The Greenstar CDi is also one of the few condensing boilers to fully condense in both heating and hot water modes. The Greenstar 25CDi CENTRAL HEATING OUTPUT 7.7-25kW HOT WATER FLOW RATE 10.5 LITRES PER MINUTE* SUITABLE FOR A SMALL/MEDIUM SIZED, 1 BATH FLAT, APARTMENT OR HOUSE. The Greenstar 30CDi CENTRAL HEATING OUTPUT 7.7-30kW HOT WATER FLOW RATE 12.6 LITRES PER MINUTE* SUITABLE FOR A MEDIUM SIZED, 1 BATH FLAT, APARTMENT OR HOUSE. The Greenstar 35CDi CENTRAL HEATING OUTPUT 7.7-30kW HOT WATER FLOW RATE 14.3 LITRES PER MINUTE* SUITABLE FOR A MEDIUM/LARGE SIZED, 1BATH FLAT, APARTMENT OR HOUSE WITH EN-SUITE SHOWER. The Greenstar 40CDi CENTRAL HEATING OUTPUT 8.6-30kW HOT WATER FLOW RATE 16 LITRES PER MINUTE* SUITABLE FOR A MEDIUM/LARGE SIZED, 1 BATH FLAT, APARTMENT OR HOUSE WITH EN-SUITE SHOWER. 14 Optional Controls A choice of optional controls is available. *At 35ºC T Mechanical Timer Mechanical RF Thermostat Digistat Programmable Room Thermostat Twin Channel Digital Programmer RF Thermostat with Twin Channel Digital Programmer Optimising Digistat Controller 7 Day Programmable Room Thermostat

The Worcester Bosch Greenstar HE Plus Condensing Combi Boiler Series The forerunner to the Greenstar CDi, the Greenstar HE Plus also condenses in both heating and hot water mode, the Greenstar HE Plus boilers can help to save up to a further 10% on fuel bills over normal condensing combi boilers. The Greenstar 30HE Plus CENTRAL HEATING OUTPUT 7.4-30kW HOT WATER FLOW RATE 12 LITRES PER MINUTE* SUITABLE FOR A MEDIUM SIZED, 1 BATH FLAT, APARTMENT OR HOUSE. The Greenstar 35HE Plus CENTRAL HEATING OUTPUT 11.4-35kW HOT WATER FLOW RATE 14.3 LITRES PER MINUTE* SUITABLE FOR A MEDIUM/LARGER SIZED APARTMENT OR HOUSE WITH 1 BATH AND A REGULAR REQUIREMENT FOR ONE OR MORE SIMULTANEOUS DRAW-OFFS OF HOT WATER. The Greenstar 40HE Plus CENTRAL HEATING OUTPUT 11.4-40kW HOT WATER FLOW RATE 16 LITRES PER MINUTE* SUITABLE FOR A MEDIUM/LARGER SIZED APARTMENT OR HOUSE WITH 1 BATH AND A REGULAR REQUIREMENT FOR ONE OR MORE SIMULTANEOUS DRAW-OFFS OF HOT WATER. Optional Controls An optional control is available. Optimising Room Temperature Controller with Flow Temperature Modulation Text display as standard *At 35ºC T 15

heating & hot water comfort The Worcester Bosch Greenstar Highflow 440 Condensing Combi Boiler With its ability to provide higher volumes of hot water on tap, the Greenstar Highflow is the perfect option for the larger family property. The Greenstar Highflow 440 CENTRAL HEATING OUTPUT 7.5-29.2kW HOT WATER FLOW RATE 20 LITRES PER MINUTE* SUITABLE FOR A LARGE, 2 BATH HOUSE. *At 35ºC T 16 Optional Controls A choice of optional controls is available. Twin Channel Programmer Optimising Room Temperature Controller with Flow Temperature Modulation

The Worcester Bosch Greenstar i Condensing System Boiler Series The perfect choice for households with a preference for stored hot water or with 2 bathrooms or more. The Greenstar 12i CENTRAL HEATING OUTPUT 4-12kW HOT WATER FLOW RATE N/A SUITABLE FOR A SMALL/MEDIUM SIZED, FLAT, APARTMENT OR HOUSE. The Greenstar 24i CENTRAL HEATING OUTPUT 7.2-24kW HOT WATER FLOW RATE N/A SUITABLE FOR A MEDIUM SIZED, FLAT, APARTMENT OR HOUSE. Optional Controls A choice of optional controls is available. Twin Channel Digital Programmer* RF Thermostat with Twin Channel Digital Programmer* Digistat Programmable Room Thermostat* *Only when an optional diverter valve is used 17

heating & hot water comfort The Worcester Bosch Greenstar Ri Condensing Regular Boiler Series Amongst the smallest appliances available, Greenstar Ri regular boilers are ideal replacements for an existing traditional boiler. The Greenstar 12Ri CENTRAL HEATING OUTPUT 4-12kW HOT WATER FLOW RATE N/A SUITABLE FOR A SMALL/MEDIUM SIZED, FLAT, APARTMENT OR HOUSE. The Greenstar 24Ri CENTRAL HEATING OUTPUT 8-24kW HOT WATER FLOW RATE N/A SUITABLE FOR A MEDIUM SIZED, FLAT, APARTMENT OR HOUSE. 18

The Worcester Bosch Greenstar CDi Condensing Regular Boiler Series If you are upgrading an existing system in a larger property the Greenstar CDi condensing conventional or regular series is the perfect choice. The Greenstar 30CDi CENTRAL HEATING OUTPUT 8-30kW HOT WATER FLOW RATE N/A SUITABLE FOR A MEDIUM/LARGER SIZED, FLAT, APARTMENT OR HOUSE. The Greenstar 40CDi CENTRAL HEATING OUTPUT 9.5-40kW HOT WATER FLOW RATE N/A SUITABLE FOR A MEDIUM/LARGER SIZED HOUSE OR NON-DOMESTIC DWELLING. 19

heating & hot water comfort What control options are offe Installing effective controls with your new high-efficiency condensing boiler will have a major impact on reducing the energy consumption of your central heating and hot water system. The benefits? Further improvements in energy efficiency, comfort, reduced running costs and lower Carbon Dioxide emissions. Worcester Bosch offers a wide variety of control options, ranging from easy-tooperate mechanical devices to much more sophisticated digital and wire-less radio frequency programmers. The key word is flexibility: whatever your lifestyle, there s a choice of controls to match your needs. Why are effective controls so important? Apart from the very desirable benefits outlined above, controls enable you to minimise energy consumption by reducing temperature levels but without any sacrifice in comfort. For example, if your room thermostat is set to 21ºC (a typical temperature setting) and you reduce it to 20ºC, your heating energy consumption can be cut by 6-10%.* The more sophisticated the controls you choose, the more precisely you can set temperature and time settings. And by timing your heating and hot water periods in tune with your lifestyle, you can reduce wasteful overheating. Do the new regulations also apply to controls? Yes. In order to comply, the minimum requirement for controls with your new high-efficiency condensing boiler are : Combi boilers A room thermostat. Thermostatic radiator valves (TRVs) on all radiators (except in the room with the room thermostat) on new systems. When replacing a boiler, TRVs are required on at least the bedroom radiators and preferably on all (with the exception of the room with the thermostat). Timer/programmer. System and regular boilers Requirements are the same as for combi boilers with the following exceptions: Instead of a timer, a full programmer must be installed enabling the heating and hot water operations to be timed independently. The system must be fully pumped. It is worth remembering that these are the minimum requirements and you can further improve your comfort levels and the economy of your heating system by exceeding these requirements. With the exception of Greenstar Ri regular and Greenstar CDi regular condensing boilers * Source: Energy Efficiency: Best Practice In Housing 20

red by Worcester Bosch? The Worcester Bosch controls range There are three different types of control available to you; basic mechanical timer, digital and RF (radio frequency) controls. MT10 Mechanical timer (for condensing combi boilers only) The simplest Worcester Bosch control device an easy-to-use analogue clock for setting heating time periods. It simply plugs into the fascia via a pre-prepared plug and socket. DT20 Twin-channel digital programmer Plugs into the boiler fascia panel and sets automatically to current time, date and day, and automatically adjusts as appropriate in line with British summer time. There are 3 time periods for both heating and hot water (separately). Use either the pre-set programme built in, or choose your own settings. MT10RF Mechanical RF (radio frequency) thermostat Analogue display for setting night and day time periods and temperature. The receiver plugs into the boiler and is activated remotely by the RF (radio frequency) controller, which requires no wiring. So installation is clean and simple no disturbance to floorboards or carpets. Nor is there any need for a separate room thermostat. DT20RF RF (radio frequency) thermostat with digital twin-channel timer As with the DT20, this features convenient automatic set-up and is very simple to operate. The timer plugs into the boiler and offers up to 3 different time periods a day, with the room thermostat (no separate thermostat required) providing the temperature control. This device also has all the no wiring benefits of the MT10RF. Twin-channel function: when used with the Greenstar i condensing system boiler, the second channel gives you 3 time periods for hot water. If used with a Greenstar condensing combi boiler, it times the KEEP HOT function (see page 25 in the Technology Guide). 21

heating & hot water comfort D10RF Digistat 24-hour programmable room thermostat (for use with Greenstar Si and CDi condensing combis only) A 24-hour programmable room thermostat (which means your time settings remain the same for every day) with 3 temperature and 6 time periods. No separate room thermostat is required and all the major benefits of no wiring requiring also apply. This also helps you to comply with Building Regulations Best Practice, as programmable room thermostats can make even further savings over more traditional room thermostats and timers. DT10RF 7-day optimising Digistat programmable room thermostat (for use with Greenstar Si and CDi condensing combis only) A sophisticated energy-saving device which automatically maintains a range of temperatures to avoid the wasteful hot-cold-hot-cold cycle. Also features an energy-saving optimum start, calculating when it needs to fire the boiler to precisely achieve the required temperature at the required time each day. You can set up to 3 temperatures and 6 time periods for each day of the week individually. As an RF (radio frequency) device it also has the additional benefits of no wiring required. Nor is a separate thermostat necessary. 7-day twin-channel programmer For use with the Greenstar Highflow 440 condensing combi boiler only, and similar to the DT20 twin-channel digital programmer but without the automatic set-up feature, this device plugs into the boiler fascia and enables you to set 2 time periods for each day of the week independently. A separate room thermostat is required, and the TR2 room temperature controller described below is the ideal recommendation. TR2 Optimising room temperature controller Perfectly suited to the Greenstar Highflow 440 and HE Plus condensing combi boilers, this monitors room temperature in order to run the boiler at the lowest temperature possible to satisfy the demand. In doing so it saves energy by increasing the effectiveness of the boiler s condensing mode. Worcester Bosch strongly recommends that the TR2 is used on HE Plus installations in conjunction with the standard text display. 22

Technology Guide Heat Exchanger This is heart of the boiler, and every Worcester Bosch Greenstar highefficiency condensing boiler has one of two proven heat exchangers a WB3 or WB5, depending on the model. The heat exchanger is a cast aluminium/silicon heat cell of robust single-piece construction to withstand the naturally occuring corrosive elements of condensate. The specially designed ridged surface provides a large surface area with excellent heat transference values hence the very high efficiency in converting the heat generated by the gas burner, which sits in a cavity within the heat cell. WB3 Heatcell WB5 Heatcell 23 2

Boiler Control Board Here are the brains behind the operation of every Greenstar the Bosch Heatronic management system, comprising a microprocessor-based printed circuit board which controls all boiler functions. For example: When there is demand for heat it ignites the burner electronically, eliminating the need for an energy wasting continuously burning pilot light. It controls the output of the boiler, modulating it between minimum and maximum in line with the sensors which constantly monitor both output and temperature. In doing so it accurately matches the output to the heating and hot water demand, resulting in optimum comfort and economy. Pump anti-seizure protection prevents the problem which is all too common in old boilers and systems failure of the pump to operate because of seizure when the boiler has been switched off for long periods. This Greenstar feature eliminates the problem by spinning the pump for 1 minute every 24 hours, even when the house is unoccupied and no heating or hot water demand has been made.. Fault diagnostics are another function of the boiler control board, enabling engineers to quickly pinpoint the area of any fault. The frost thermostat protects the boiler and pipework by monitoring the water temperature in the heating system. Should this fall below 8ºC, the thermostat automatically engages a 3-stage cycle to supply just the right amount of heat (minimal energy) to prevent freezing. This feature is particularly important in instances where the boiler is installed in a cold environment, such as in a garage. The anti-cycle control is a delay timer which prevents rapid cycling (on-off operation) incurred by older boilers with a low water content. Cycling is costly in terms of both energy consumption and excessive wear on components 24

Hydraulic Block This controls all the hydraulicallyoperated components in the boiler, namely the circulating pump, automatic bypass, diverter valve and flow turbine. The built-in circulating pump on system boiler models distributes the hot water around the system to radiators and to the coil within the hot water cylinder. Cooled water is returned to the boiler to be reheated and re-circulated. Regular boilers have an external pump which fulfils the same function. Combi boilers also have an integral circulating pump which distributes primary water around both the hot water heat exchanger or the heating system. The appliances incorporate a diverter valve (see opposite) which controls both functions, although the priority will always be given to the supply of hot water The automatic bypass is a new Building Regulations requirement. It protects the pump by providing it with an alternative route to circulate water should all the radiator valves be shut off. The diverter valve features on Greenstar condensing combis and is an optional extra on Greenstar condensing system boilers. The primary heating water circulated by the pump goes first to the diverter valve, which based on system demand decides where it will go next to the radiators, hot water cylinder, or the heat exchanger if a combi. The flow turbine is a feature on Greenstar condensing combis only. During hot water demand it measures the volume of water flowing through the hot water taps and delivers precisely the amount of heat required accordingly thereby saving gas and improving energy efficiency. Hydraulic Block Diverter Valve Keep Hot Function This is a function of all Greenstar condensing combis and ensures that whenever a hot tap or shower is turned on, hot water is supplied more quickly than combis without this feature. It achieves this by periodically re-heating the small volume of water that is held within the boiler so that when hot water is required, it takes less time to heat the water and deliver to the appropriate outlet. 25

Heating Controls The majority of heating systems have at least two controls: a time clock or programmer and room thermostat. In fact, this is the minimum level of electrical controls specified by the Building Regulations. Timer or Programmer This operates the heating system to turn on for set periods of time. As a dial or digital, it can be either wall mounted near to the boiler or attached to the fascia panel of the boiler itself. It will take at least 30 minutes for your home to reach the desired temperature when the boiler fires up, depending on insulation levels and outside temperature. So, set the timer to come on 30 minutes before you wake up in the morning. And, don't forget to readjust the timer when the clocks go forward and back. Room Thermostat This controls the air temperature and is usually positioned in the hall or landing or in an unheated room. The thermostat can be analogue or digital. Remember to site it away from direct sunlight and clear of curtains and furniture. As a guideline, your thermostat should be set between 18ºC and 21ºC. Programmable Room Thermostat This allows you to programme the temperature levels to alter according to different times of the day and night. When programmed correctly this type of control prevents the system having to heat the house from a cold start. The control always maintains a temperature within the property (as defined by the user). This ensures that the boiler is only ever topping up the temperature in the house. Frost Thermostat This is fitted either outside or in an unheated space, such as a garage. When weather conditions are extremely cold, the frost thermostat will operate the boiler and heating system even if the programmer is in an off position. This prevents the heating system and pipework being subjected to frost. A frost protection control is included in all Greenstar appliances, generally this is sufficient to protect the appliance. Some installations may require an additional frost thermostat wired in conjunction with a pipe thermostat. This is perhaps where there is exposed pipework or radiators in conservatories, garages etc. Radiators There are three major components connected to a radiator a manual air release vent, a lockshield radiator valve and a manual or thermostatic radiator valve. Manual Air Release Vent This is where any air within the radiator can escape. Radiators must be free of air and full of water to operate effectively, and by opening the vent with a special air vent key, excess air can be released. Lockshield Radiator Valve When you have a new heating and hot water system installed, your installer should regulate the lockshield radiator valve so that the radiator heats up evenly throughout. Generally there is an approximate 20ºC difference between the incoming flow of hot water and the outgoing water with a condensing boiler. Thermostatic Radiator Valves (TRVs) The majority of radiators are fitted with these. They allow you to control the temperature of each room individually. The higher the number shown on the TRV, the hotter the room temperature, with the maximum being around 22ºC. Ideally, the TRV should be well exposed and not obstructed by furniture or curtains so that it can accurately detect the room temperature. Occasionally, it will shut down the radiator because the room has reached its maximum temperature. 26

The Greenstar condensing boiler range specification and features CONDENSING REGULAR BOILERS CONDENSING SYSTEM BOILERS CONDENSING COMBINATION BOILERS Feature 12 Ri 24 Ri 30 CDi 40 CDi 12 i 24 i 24 i Junior 28 i Junior 25 Si 30 Si 25 CDi 30 CDi 35 CDi 40 CDi 30 HE Plus 35 HE Plus 40 HE Plus Highflow 440 Wall Hung (W) Floor W W W W W W W W W W W W W W W W W F Standing (F) Height (mm) 600 600 760 760 710 710 710 710 710 710 760 760 760 760 850 850 850 850 Width (mm) 390 390 440 440 400 400 400 400 400 400 440 440 440 440 440 440 440 600 Depth (mm) 270 270 360 360 330 330 330 330 330 330 360 360 360 360 360 1 360 1 360 1 600 DHW Flow Rate @ N/A N/A N/A N/A N/A N/A 9.8 11.4 10.2 12.3 10.2 12.3 14.3 16 12 14.3 16 20 35 C T CH Output (kw) 4-12 8-24 8-30 9.1-40 4-12 8-24 7.5-24 8-28 7.5-25 7.5-30 7.7-25 7.7-30 7.5-30 7.5-30 7.4-30 11.4-35 11.4-40 7.5-29.2 Multi-directional Fluing LH, RH, Rear and Vertical Maximum 100mm 100mm 100mm 100mm 100mm 100mm 100mm 100mm 100mm 100mm 100mm 100mm 100mm 100mm 100mm 100mm 100mm 100mm Horizontal Flue 4,000 4,000 7,900 2,600 4,600 4,600 4,600 4,600 4,600 4,600 10,000 7,900 6,500 2,600 4,000 4,000 3,500 4,000 Length (mm) 125mm 125mm 125mm 125mm 125mm 125mm 125mm 125mm 125mm 125mm 125mm 125mm 125mm 125mm 125mm 125mm 125mm 125mm (inc. terminal) 13,000 13,000 18,500 12,500 13,000 13,000 13,000 13,000 13,000 13,000 23,000 18,500 16,000 12,500 13,000 10,000 10,000 13,000 Maximum 100mm 100mm 100mm 100mm 100mm 100mm 100mm 100mm 100mm 100mm 100mm 100mm 100mm 100mm 100mm 100mm 100mm 100mm Vertical Flue 6,400 6,400 9,400 4,900 6,400 6,400 6,400 6,400 6,400 6,400 11,500 9,400 8,000 4,900 6,400 6,400 5,400 6,400 Length (mm) 125mm 125mm 125mm 125mm 125mm 125mm 125mm 125mm 125mm 125mm 125mm 125mm 125mm 125mm 125mm 125mm 125mm 125mm (inc. terminal) 15,000 15,000 18,500 16,000 15,000 15,000 15,000 15,000 15,000 15,000 23,000 18,500 16,000 16,000 15,000 12,000 12,000 15,000 Modulation CH CH CH CH CH CH of CH and DHW only only only only only only Electronic Ignition Built-in Bypass * * * * * * * * Built-in Filling Link Optional Optional Optional Optional Optional Optional Built-in Frost Thermostat Optional Plug In Text Text Text Timeclocks Display Display Display Mechanical (M) D 2 D 2 M/D M/D M/D M/D M/D M/D M/D M/D as as as Digital (D) Standard Standard Standard Optional Wireless Room Thermostats 2 2 Pipes Behind Boiler Ventilation Free Compartment Installation Sedbuk Number (%) 90.1% 90.2% 90.3% 90.2% 90.1% 90.2% 90.1% 90.1% 90.1% 90.1% 90.3% 90.3% 90.3% 90.2% 90.6% 90.3% 90% 91% and Band LPG Version Fault Finding Diagnostics Pre-plumbing Jig NOTE: This matrix is for a guide only, full technical details are available within the Technical Specification brochures for these products. 1 395mm with wall spacing frame 2 Only when an optional built-in diverter valve is used * No Bypass required With Conversion Kit 27 D

The famous Bosch quality As part of the worldwide Bosch Group, Worcester Bosch is renowned for superlative quality, reliability and customer service. Working for a cleaner environment Alongside the need for warm, comfortable homes is the bigger need to conserve the earth s non-renewable energy resources. This is why Worcester Bosch is totally committed to finding new ways in which to use gas as efficiently as possible, and to meeting and exceeding all current and future environmental regulations. All the reassurance of a complete aftersales service Worcester Bosch quality applies not only to the design and manufacture of each and every boiler, but also to standards of aftersales service. So if your boiler needs attention for any reason, expert help is only a telephone call away. Excellent parts availability, along with your guarantee and the extended warranty options are further proof that a boiler made by Worcester Bosch is made to be the best. www.worcester-bosch.co.uk The Council for Registered Gas Installers Energy Efficiency is an Energy Saving Trust initiative backed by the Government. Worcester, Bosch Group, Cotswold Way, Warndon, Worcester, WR4 9SW Tel: 01905 754624 Fax: 01905 754619 This leaflet is accurate at the date of printing, but may be superseded and should be disregarded if specification and/or appearances are changed in the interest of continued improvement. The statutory rights of the consumer are not not affected. Part No. 8 716 109 642 Issue A WH1523