is a combi boiler?
Combination boiler or combi boilers are the most
commonly type of boilers which are used in UK for a reason. Unlike the system
and conventional boilers which requires a hot storage cylinder, the combination
cylinder is an all in one unit which produces hot water for taps and central
heating. Also it saves a great space in your homes and its installation is easy
and faster comparative to any other boiler.
It usually takes the water from the main supply and
results in stronger water pressure. It provides you plenty of hot water. Thus,
no longer waits for the tank to refill again and again.
Modern high efficiency unit boilers are the
stainless steel condensing boilers with its built-in heat exchanger to provide
hot water to a home or a building. During the cold season, combi boiler runs
when needed to heat the structure and provide hot water to various hot
appliances. Whereas in hot summer days, combi boiler works whenever there is a
need for domestic hot water.
There are two main reasons behind the combi boilers
great and powerful efficiency i.e. these units have high operating efficiency
and low internal water volume. This means when in summer days you don’t need
space heating you are only paying to heat hot water which is domestically
Sometimes it happens that we need to drain and then
refill the system. You might be thinking of how to drain and refill central
heating system with a combi boiler?
you start the process keep in mind to turn off the boiler and disconnect it
from the power supply. So that cut off couldn’t be there.
let the system water to cool down and reduce the overall pressure.
the draining system it I important to maintain the minimal temperature of the
the drainage of the boiler
locate the drainage point in the system, usually it is located at the lowest
point of the lowest radiator in the property.
found the drainage point, connect a hose securely using a jubilee clip.
the clip over the hose to prevent the leakage
move the other end to the hose of the drainage point.
that every valve on each of the radiator is open to know that system is drained
the drainage head with the help of spanner or wrench.
should see water flowing out of the hose.
– you can speed up the replacement of water with air by opening the vents at
the top of the radiators.
During refilling of the
close all the air bleed valves of your radiator and then close the drainage
valve and remove the hose.
the braided filling loop beneath your boiler. This connects the cold feed and
the return feed.
open the filling loop and allow the boiler to refill to the recommended level
by the manufacturer.
the bleed valve of each radiator and allow the air to escape.
you have released the air from the radiator, return back to the filling lop and
top up the system’s pressure.
keep a check there should not be any leaks in your boiler systems.
soon as the boiler heats up, you need to bleed the air-bleed-valves. This
process has to be repeated several times so as to ensure all the air is removed
from the system.
top up the pressure as required.
water temperature increases connections causing water to escape.
These steps may seem very easy to
perform but in practice it can be difficult. So, begin with the process once
you are sure about what you are doing else contact an engineer for the same.