Valves that are known as zone valves are fitted to a heating system to help control the heat from a thermostat for an area of a home, like a bedroom or living room. A control box is connected to thermostats in a home and this provides the control for the zone valves. As a zone valve receives an electrical signal from a thermostat, it will open or close, which allows heated water from a boiler to pass or not through an open zone valve to heat the selected area. These valves can control temperature, pressure and levels. A Willesden Plumber is qualified to work on all appliances.Two types of valve which feature in central heating systems are operated by electrical current. First of all there is the valve which is called a two-port valve that carries out an on and off operation within the system. A second valve that features is called a Three Port Valve or is better known as (diverter valve) with the primary task of diverting the flow of water as it moves through the hot eater cylinder as needed. The jobs these two valves carry out is important so the flow direction is clearly marked on them. Willeseden Plumbers only sully fully ualified plumbing professionals. They are quite resilient but, sometimes they can start to show their age, when things like seals fail and that could cause a leak. Electrical failure as well like wiring to automatic valves can perish also. Not too expensive to buy, however if you need to replace one, then, it is a good idea before purchasing a new valve to check and test the old one first just to make sure that the problem is not in the wiring or timer etc. This can be done by a novice as long as they are confident to do it, if not it is a good idea to pass it to a professional. The wiring can be disconnected on the valves in case of emergency, which allows the system to carry on working.