Water circulation.It can be that the water in the radiator pipes (in different homes) is pumped around the hot water cylinder by gravity (called convection), whist in others, it is done with the use of a pump and electric valves forcing the water through the cylinder. Kensington Plumbers are experienced professionals.Maintenance.These heating systems contain quite a lot of water, which, of course can cause the pipework (especially Radiators) to rust. A dark muddy mess is produced and sits in the bottom of the radiators, thus, reducing their efficiency. You can buy chemical additives for cleaning the system which will also protect it. A Kensington Plumber can carry out maintenance and servicing schedules. The Boiler.Your boiler will have a model number that allows you to know what system you have. It will also have the makers detail, should you need to find out any more information for spares etc. make a list of the model, year, and any code numbers. Central Heating Systems (sealed).Sealed central heating systems let the water expand when heated via an expansion cylinder. If you have this type of system, there will be a small pressure gauge somewhere on your central heating boiler giving a visual indication of the pressure.Pipework.Central heating systems have 15mm pipework to the radiators. It could be that if your pipes are much bigger than this, you may have an old style ‘one pipe’ system, where the water is pumped around the loop and diverted to each radiator by convection.Advantage of a Combination Boiler.This boiler system needs no tanks or pipes to be fitted in the loft. It is economical because you only heat the water that’s used. The negative feature is that, while the water coming from the hot tub is very hot, the flow is quite slow. It is, however, is a good setup for a small apartment or flat.. “