Gravity C H System

For this system to work, the water runs into your home through the stop-tap and, then, moves up into your loft space

Now, it will go through a ball valve and begin to fill a small tank, which is known as a feed and expansion tank. N11 Plumbers can fit, service and repair the CH system. The force of gravity allows the water to leave the tank, to your boiler and then on to the radiators. This is why it is called gravity fed. When the system is full the valve closes, the process is complete, and the water within your boiler and radiators will now circulate round and round, for possibly years. It never leaves the circuit. An N11 Plumber can identify a gravity system. This means that you can turn off your cold water mains when you go away, yet still leave your central heating on. How do you find out if this is the sort of CH system you have? Well, the best way is to go up into your loft and look for your feed and expansion tank. It is a fairly small tank approximately 500mm by 300mm by 300mm and if there are two or more tanks up in your loft this one will be the smaller. Look inside you’ll see that the tank is less than half full and that the water it contains looks foul enough to put you off using it. If you can’t find this tank in your loft, try looking in the airing cupboard. You just need to bear in mind that it must be the highest point in your whole CH system, so it has to be higher than any of your radiators. If you can’t find this tank you probably have a high pressure CH system.
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