Emergency Boiler Repair/ 24HR Boiler Breakdown Repair Engineers
The combination boiler description applies to an indirect combination boiler where the domestic hot water is heated in a secondary calorifier. See below for more about a direct combination boiler. Our projects section also contains lots of information about central heating of all kinds including oil fired.
Combination boilers combine the functions of a central heating boiler and an instantaneous multi point water heater. They give priority, in the main, to the supply of domestic hot water (dhw). The combination boiler has all its operating components contained within the casing and is typically designed for use within a sealed central heating system.
Installation is made easier by incorporating an expansion vessel, thus eliminating the need for a feed and expansion cistern in the roof space. Like an ordinary boiler it will have a gas fired burner and a heat exchanger. The waterways of both form part of the central heating system. In most of the early designs of combination boiler, hot water from the heat exchanger passes to a diverter valve, which directs the flow to a domestic hot water calorifier or central heating circuit. The calorifier is tightly packed with small copper tubes, through which secondary water flows the moment the hot water draw off is opened. As the water flows it picks up heat from the surrounding primary water in the calorifier. The central heating system is pressurised and needs a relief valve to protect against any build up of pressure in the system.
A pressure gauge on the appliance indicates the operating pressure. A by-pass, connected across the primary flow and return, ensures that an adequate flow of water is maintained. This by-pass may, or may not be a built in feature of the appliance.
The flue arrangements for combination boilers may be open, room sealed, fan assisted & room sealed, fan assisted open, miniature flue/condensing or se-duct. The primary heating circuit of combination boilers should be pre-commissioned, cleansed and treated with a corrosion protector in the same way as any other heating system. In hard water areas, the secondary domestic hot water should be treated with an in-line scale reducer or water softer (See projects section for info on both of these) This will prevent the build up of limescale on the instantaneous water heater and the accompanying reduction in flow rate and water outlet temperature.
With a direct combination boiler the secondary water is heated in one of two ways. The water may pass through pipes which run down the inside, or next to the primary pipes in the heat exchanger, or by passing through a separate heat exchanger which is bolted on top of the main heat exchanger. A direct combination boiler does not need a diverter valve or a secondary calorifier.
In a domestic hot water system where the (condensing) boiler is a replacement for an existing storage cylinder system or a conventional boiler, it is essential that all redundant pipework is removed to eliminate "dead legs" which can hold air and cause air locks. These can also cause cold spots and slow burner shut off.
Our Gas safe registered - (previously corgi) gas engineers have been recommended and trained properly so they can deal with all gas combi boilers, oil condensing boilers, gas condensing boilers, vaillant condensing boilers ,Gledhill system. We normally send our Corgi registered engineers to do gas engineer training every so often. This is what makes us different to other engineers from other companies as we know once they all have been through the training they will become more confident and they can deal with difficult situations of complicated jobs.
When we do the service on gas boilers we service them and do proper checks. We always comply with gas regulations all the time so that you will be assured that everything , every job will be done up to really high standard that is set by the government.
When doing some central heating installations – if they are quite involved jobs or if a few engineers are ever required on sites to complete the jobs. We will be able to accommodate by sending a team of experienced central heating installers who are top class and they know how to deal with unforeseen complications. All jobs are different and they depend on the type of the property, some will need bosch combi boiler, some are suitable for combi boiler installation and some will be more suitable for condensing combination boilers but ever process and possibility will be explained to you so that you know what to expect and not to expect.
