Gravity fed central heating

In a gravity fed system water rushes into your home through the stop tap and, with barely a pause, races up into your loft. Once there, it passes through ball valve and starts filling a small tank, called the feed and expansion tank. Harringay Plumbers can identify CH systems.Good old gravity now kicks in and under its own influence water flows out of this tank, down to your boiler and into all your radiators, hence the term gravity fed. Once the system is full the ball valve closes and that’s pretty much it, the water within your boiler and radiators now circulates around and around, possibly for years at a time. It never leaves the circuit. This is the reason why you can turn off your cold water mains when you go on holiday, yet still leave your central heating on to keep your home warm. So how do you find out if this is the sort of CH system you have? Well, the easiest way is to go up into your loft and look for this feed and expansion tank. A Harringay Plumber will know your tank. It will be a fairly small tank approximately 500mm long by 300mm wide by 300mm high and if there are two or more tanks up in your loft this one will be the smallest. If you take a 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 drinking it. If you can’t find this tank in your loft, try looking in the airing cupboard. In terms of location 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, quite a bit higher. If you can’t find this tank you probably have a high pressure CH system.
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