What is a Condensing
Boiler?
A condensing boiler
is a high efficiency
modern boiler that
incorporates an
extra heat exchanger
so that the hot
exhaust gases lose
much of their energy
to pre-heat the
water in the boiler
system. When working
at peak efficiency,
the water vapour
produced in the
combustion process
condenses back into
liquid form
releasing the
latent heat of
vaporisation. A
side effect is that
this water, known as
condensate, which is
usually acidic, has
to be piped away to
a drain or soakaway.
Combination
condensing
boilers.
It is mounted on a
wall and the exhaust
gases will rise
through the plastic
flue in the top left
corner. Hot water is
provided by a small
storage tank on the
right: the tank
(which is covered by
insulating foam) has
been cut open to
show the tightly
wound quick refresh
coil inside it. At
the bottom are a number
of pipes going into
the boiler. One
carries the gas for
the burner and there
are two (in and out)
for the central
heating system. The
plastic pipe on the
right carries the
condensed water
vapour produced by
burning the gas.
This water contains
dissolved oxides of
sulphur and
nitrogen, making it
slightly acidic. |
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What size of Boiler do I need?
Most existing boilers are measured
by their output in British Thermal
Units per hour (Btu/h), but all
current boilers are sold in the
metric equivalent of kilowatts (kW) but you
should bear in mind that in the past
central heating engineers often
installed boilers that had a higher
output than strictly necessary.
Although this meant that there was
no possibility of the boiler failing
to meet the demand for heat, even in
the most arctic of conditions, it
also meant that they were mainly
operating at a part load, and so
running below their maximum
efficiency. If you have installed
additional loft or cavity wall
insulation since the last boiler was
fitted, it is highly likely that you
will need a smaller boiler than
before.
We recommend seeking professional
advice from a CORGI or OFTEC
registered installer before choosing
an appropriate replacement boiler.
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Where can I find an installer for a
condensing boiler?
Most CORGI registered gas engineers
in the UK should be able to fit a
condensing boiler. Until recently
builders were reluctant to install
condensing boilers because there
were only a limited number of models
available and they were rather
expensive. Prices have fallen
sharply over the past few years, so
there are no longer nationally
available grants or cashbacks for
boilers at present, but EEACs may
know of local offers. Some local
councils have also grouped together
to bulk purchase boilers on behalf
of their residents; again local
advice centres will know if there is
such a scheme operating in your
council district.
You may also find a local installer
who belongs to the Energy Efficiency
Installers scheme. These have been
through additional training in
energy efficiency, so you can be
extra confident of receiving good
advice about the best boiler for
your home. |
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What controls do I need with a high
efficiency boiler?
Good heating controls require a
minimum of four things:
-
an
electronic timer or programmer
that allows separate switching
of heating and hot water
-
a
room thermostat
-
thermostatic radiator control
valves (TRVs), and
-
separate thermostatic control on
the hot water system
Additional controls that may be
worth considering to get the very
best from a central heating system
include intelligent heating
controls, a weather compensator, a
boiler energy manager and full zone
control. |
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Radiators (central
heating radiators, radiator covers, towel radiators,
designer radiators)
Radiator 'heat
emitters' can come in all shapes, sizes and forms.
The most common
central heating radiator is the steel panel type
radiator and they are available in a very wide range
of sizes and styles intended to match as closely as
possible individual room needs.
Aluminium radiators
are becoming increasingly popular, whilst the use of
cast iron radiators is also on the increase where
the intention is to blend with existing traditional
decoration. Towel radiators are most often used in
bathrooms and WC's where the towel radiator can be
used to store towels as well as heat the room
as a bathroom radiator. Designer radiators are more
money but designer radiators can make a design
statement and be a feature in a room. You may decide
to cover up a radiator with a radiator cover, this
may be because the radiator is old or unsightly.
Radiator covers come in many designs to suit your
room decor and most radiator covers are made from
mdf. Some radiator covers can be painted in your own
colour scheme.
Radiators need to
be matched to the room size and also how the room
will be used to ensure the correct temperature can
be maintained. How the house is insulated, including
double glazing, can alter how efficient the
radiators are at warming a house.
Worcester Bosch boilers Potterton
Boilers Central heating boilers and radiators
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