WH1523 ConsumerCond Bro [Iss.A]

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
h efficiency boilers
se 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
Contents
Page
What is a high-efficiency
condensing boiler?
4
What type of condensing boiler
is best for me?
6
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).
What are the benefits of
choosing Worcester Bosch?
10-11
Greenstar condensing combi boilers
12-16
Greenstar condensing system boilers
17
• 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
Greenstar condensing regular boilers 18-19
What controls options are
offered by Worcester Bosch
20-22
The Technology Guide
23-26
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.
3
Greenstar condensing boiler range
specification & features
27
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 CO2 (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
Most suitable boiler
You want to use your loft space for a
room conversion or other purpose
COMBI
You live in a flat or bungalow
(i.e. have very little or no roofspace)
COMBI
Your home has more than 2 bathrooms
REGULAR OR SYSTEM
Your mains water pressure is low
REGULAR OR SYSTEM
You want to replace an old boiler to
improve an existing conventional
central heating system
REGULAR, SYSTEM OR COMBI
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
COMBI
6
ler 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 to Baths, Showers
and Basins etc.
Hot
Water
Cylinder
Motorised
Valve
Pump
Programmer
Room
Thermostat
Worcester
Bosch
Regular
Boiler
Hot to
Basins and
Appliances
etc.
The combi
system layout
Hot to
Baths,
Showers
and Basins
W orcester
Bosch Combi
Boiler
Room
Thermostat
Hot to Basins
and Appliances etc.
The system
boiler layout
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
System boiler with
low pressure hot
water cylinder
water storage cistern located in the loft.
Cold W ater
Storage
Cistern
Hot to Baths, Showers
and Basins etc.
What else should I consider when
investing in a new boiler?
• Quality
• Efficiency
• Reliability
• Controllability
• Back-up service
• Long-term as
Hot
Water
Cylinder
Motorised
Valve
Programmer
Room
Thermostat
Worcester
Bosch
System
Boiler
System boiler
with unvented hot
water cylinder
Hot
Water
Cylinder
Motorised
Valves
Programmer
well as current needs
9
Worcester
Bosch
System
Boiler
Room
Thermostat
Hot to
Basins and
Appliances
etc.
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
er 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.
Optional Controls
A choice of optional controls is available.
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.
Mechanical Timer
The Greenstar 28i Junior
Twin Channel
Digital Programmer
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.
Mechanical RF Thermostat
RF Thermostat with
Twin Channel Digital Programmer
Digistat Programmable
Room Thermostat
*At 35ºC ∆ T
12
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.
Mechanical Timer
The Greenstar 30Si
Twin Channel
Digital Programmer
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 RF Thermostat
Digistat Programmable
Room Thermostat
*At 35ºC ∆ T
13
RF Thermostat with
Twin Channel Digital Programmer
Optimising Digistat Controller
7 Day Programmable
Room Thermostat
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.
Optional Controls
A choice of optional controls is available.
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.
Mechanical Timer
Twin Channel
Digital Programmer
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
Mechanical RF Thermostat
CENTRAL HEATING OUTPUT – 7.7-30kW
HOT WATER FLOW RATE – 14.3 LITRES PER MINUTE*
SUITABLE FOR A MEDIUM/LARGE SIZED,
1 BATH FLAT, APARTMENT OR HOUSE WITH
EN-SUITE SHOWER.
The Greenstar 40CDi
Digistat Programmable
Room Thermostat
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.
*At 35ºC ∆ T
14
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.
Optional Controls
An optional control is available.
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.
Optimising Room
Temperature Controller with
Flow Temperature Modulation
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.
*At 35ºC ∆ T
15
Text display
as standard
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.
Optional Controls
A choice of optional controls is available.
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.
Twin Channel
Programmer
*At 35ºC ∆ T
16
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.
Optional Controls
A choice of optional controls is available.
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
Twin Channel
Digital Programmer*
CENTRAL HEATING OUTPUT – 7.2-24kW
HOT WATER FLOW RATE – N/A
SUITABLE FOR A MEDIUM SIZED,
FLAT, APARTMENT OR HOUSE.
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 –
WB3 Heatcell
hence the very high efficiency in
converting the heat generated by the
gas burner, which sits in a cavity within
the heat cell.
WB5 Heatcell
23
2
Boiler Control Board
Here are the brains behind the
• Pump anti-seizure protection
operation of every Greenstar – the
prevents the problem which is all
Bosch Heatronic management system,
too common in old boilers and
comprising a microprocessor-based
systems – failure of the pump
printed circuit board which controls all
to operate because of seizure
boiler functions. For example:
when the boiler has been
• When there is demand for heat it
switched off for long periods.
ignites the burner electronically,
This Greenstar feature eliminates
eliminating the need for an energy
the problem by spinning the pump
wasting continuously burning
for 1 minute every 24 hours, even
pilot light.
when the house is unoccupied and
• It controls the output of the boiler,
modulating it between minimum
and maximum in line with the
no heating or hot water demand
has been made..
• Fault diagnostics are another
sensors which constantly monitor
function of the boiler control board,
both output and temperature. In
enabling engineers to quickly
doing so it accurately matches the
pinpoint the area of any fault.
output to the heating and hot water
demand, resulting in optimum
comfort and economy.
• 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 hydraulically-
• The automatic bypass is a new
operated components in the boiler,
Building Regulations requirement.
namely the circulating pump, automatic
It protects the pump by providing it
bypass, diverter valve and flow turbine.
with an alternative route to
• The built-in circulating pump on
system boiler models distributes
the hot water around the system to
circulate water should all the
radiator valves be shut off.
• The diverter valve features on
radiators and to the coil within the
Greenstar condensing combis and
hot water cylinder. Cooled water is
is an optional extra on Greenstar
returned to the boiler to be
condensing system boilers. The
reheated and re-circulated. Regular
primary heating water circulated by
boilers have an external pump
the pump goes first to the diverter
which fulfils the same function.
valve, which based on system
Combi boilers also have an integral
demand decides where it will go
circulating pump which distributes
next – to the radiators, hot water
primary water around both the hot
cylinder, or the heat exchanger if
water heat exchanger or the
a combi.
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
Hydraulic Block
• 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.
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
Diverter Valve
Heating Controls
The majority of heating systems have at least two controls: a time
Programmable Room Thermostat
clock or programmer and room thermostat. In fact, this is the
This allows you to programme the temperature levels to alter
minimum level of electrical controls specified by the Building
according to different times of the day and night. When
Regulations.
programmed correctly this type of control prevents the system
Timer or Programmer
having to heat the house from a “cold start”. The control always
This operates the heating system to turn on for set periods of
maintains a temperature within the property (as defined by the
time. As a dial or digital, it can be either wall mounted near to the
user). This ensures that the boiler is only ever “topping up” the
boiler or attached to the fascia panel of the boiler itself.
temperature in the house.
It will take at least 30 minutes for your home to reach the desired
Frost Thermostat
temperature when the boiler fires up, depending on insulation
This is fitted either outside or in an unheated space, such as a
levels and outside temperature.
garage. When weather conditions are extremely cold, the frost
thermostat will operate the boiler and heating system even if the
So, set the timer to come on 30 minutes before you wake up in
programmer is in an off position. This prevents the heating
the morning. And, don't forget to readjust the timer when the
system and pipework being subjected to frost. A frost protection
clocks go forward and back.
control is included in all Greenstar appliances, generally this is
Room Thermostat
sufficient to protect the appliance. Some installations may require
This controls the air temperature and is usually positioned in the
an additional frost thermostat wired in conjunction with a pipe
hall or landing or in an unheated room. The thermostat can be
thermostat. This is perhaps where there is exposed pipework or
analogue or digital. Remember to site it away from direct sunlight
radiators in conservatories, garages etc.
and clear of curtains and furniture. As a guideline, your
thermostat should be set between 18ºC and 21ºC.
Radiators
There are three major components connected to a radiator –
Thermostatic Radiator Valves (TRVs)
a manual air release vent, a lockshield radiator valve and a
The majority of radiators are fitted with these. They allow you to
manual or thermostatic radiator valve.
control the temperature of each room individually. The higher the
Manual Air Release Vent
number shown on the TRV, the hotter the room temperature, with
This is where any air within the radiator can escape. Radiators
the maximum being around 22ºC.
must be free of air and full of water to operate effectively, and
Ideally, the TRV should be well exposed and not obstructed by
by opening the vent with a special air vent key, excess air can
furniture or curtains so that it can accurately detect the room
be released.
temperature. Occasionally, it will shut down the radiator because
Lockshield Radiator Valve
the room has reached its maximum temperature.
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.
26
The Greenstar condensing boiler range
specification and features
Hig
hfl
ow
44 0
HE
Plu
s
HE
HE
CD
i
CD
i
CD
i
CD
i
Si
Si
iJ
uni
or
Jun
ior
W
W
W
W
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
1
1
1
40
40
W
35
W
30
W
40
W
35
W
30
W
25
W
30
W
25
W
28
W
24
i
W
24
i
W
12
i
W
Wall Hung (W)
Floor
Standing (F)
30
24
Ri
CD
i
Plu
s
CONDENSING COMBINATION BOILERS
Plu
s
CONDENSING
SYSTEM BOILERS
12
Ri
Feature
CD
i
CONDENSING REGULAR BOILERS
Depth (mm)
270
270
360
360
330
330
330
330
330
330
360
360
360
360
360
360
360
600
DHW Flow
Rate @
35°C ∆T
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
CH Output (kW)
4-12
8-24
8-30 9.1-40 4-12
8-24
Multi-directional
Fluing LH, RH,
Rear and Vertical
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
100mm
100mm
100mm
100mm
100mm
100mm
100mm
100mm
100mm
100mm
100mm
100mm
100mm
100mm
100mm
100mm
100mm
100mm
Maximum
Horizontal Flue
Length (mm)
(inc. terminal)
Maximum
Vertical Flue
Length (mm)
(inc. terminal)
Modulation
of CH and DHW
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
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
125mm
125mm
125mm
125mm
125mm
125mm
125mm
125mm
125mm
125mm
125mm
125mm
125mm
125mm
125mm
125mm
125mm
125mm
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
100mm
100mm
100mm
100mm
100mm
100mm
100mm
100mm
100mm
100mm
100mm
100mm
100mm
100mm
100mm
100mm
100mm
100mm
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
125mm
125mm
125mm
125mm
125mm
125mm
125mm
125mm
125mm
125mm
125mm
125mm
125mm
125mm
125mm
125mm
125mm
125mm
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
CH
only
CH
only
CH
only
CH
only
CH
only
CH
only
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
Electronic
Ignition
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
Built-in
Bypass
✗
✗
✗
✗
✔
✔
✔
✔
✔
✔
✔*
✔*
✔*
✔*
✔*
✔*
✔*
✔*
Built-in
Filling Link
✗
✗
✗
✗
✔
✔
✔
✔
✔
✔
✔
✔
Built-in Frost
Thermostat
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
Optional Plug In
Timeclocks
Mechanical (M)
Digital (D)
✗
✗
✗
✗
D2
D2
M/D
M/D
M/D
M/D
M/D
M/D
M/D
M/D
Optional Wireless
Room Thermostats
✗
✗
✗
✗
✔2
✔2
✔
✔
✔
✔
✔
✔
✔
✔
Pipes Behind
Boiler
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
Ventilation Free
Compartment
Installation
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
Sedbuk
Number (%)
and Band
Optional Optional Optional Optional Optional Optional
Text
Text
Text
Display Display Display
as
as
as
Standard Standard Standard
D
✔
✗
✗
✗
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
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%
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
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
All the reassurance of a
complete aftersales service
Alongside the need for warm, comfortable
Worcester Bosch quality applies not only
homes is the bigger need to conserve the
to the design and manufacture of each
earth’s non-renewable energy resources.
and every boiler, but also to standards of
This is why Worcester Bosch is totally
aftersales service. So if your boiler needs
committed to finding new ways in which
attention for any reason, expert help is
to use gas as efficiently as possible, and
only a telephone call away. Excellent parts
to meeting and exceeding all current and
availability, along with your guarantee and
future environmental regulations.
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
Energy Efficiency is an Energy Saving Trust
initiative backed by the Government.
The Council for
Registered Gas
Installers
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
Worcester, Bosch Group,
Cotswold Way, Warndon, Worcester, WR4 9SW
Tel: 01905 754624 Fax: 01905 754619