An indirect or gravity fed water supply system is probably the most common system that is found in modern homes. It is supplied by mains water that comes in from a rising main and feeds at least one cold tap at the kitchen sink straight away with ‘potable’ water (drinking, cooking etc) and maybe a washing machine, a shower and an outside tap. Then it will move through a ball valve and begins to fill a small tank. This is called the feed and expansion tank. Camden Plumbers are trained on all systems. The force of gravity now takes over the water and under its own influence it flows from this tank and on to your domestic heating boiler and then, into all your radiators, which is why it is called gravity fed. Once the system is completely full, this ball valve shuts off and that’s about all there is to it. The water that is now in your boiler and radiators now, circulating all around for what could be years. This water now stays put and will never really leave the circuit and is the main reason that you can turn off your cold water mains when you go on holiday, but still leave your central heating on to keep your home warm ready for your return. What is the best way to find out if your system is a gravity fed one or not? Well, the easiest way is to go up into your loft and look for a feed and expansion tank, which is a fairly small tank of around 500x300mm. Camden Town Plumbers use skilled tradespeople. Now if there are two or more tanks up in your loft the smallest one will be the feed and expansion tank. Look into the tank and you will notice that the tank is less than half full and the water in it looks foul enough to put you off drinking. 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. Of course if there is no tank, then you will be fitted with a high pressure sealed system.