Hi, we have a gravity fed system with a large floor standing gloworm boiler, approx 9 years old. Firstly the 3 port valve started clicking like crazy and the heating/ hot water would only work when the switch was put on manual, but it kept popping itself off manual and so the heating etc kept going off. The plumber replaced the 3 port valve and nothing changed but then the thermostat seemed to stop clicking. So we got the plumber back, hes now replaced the thermostat and nothing has changed still! The hot water and heating will work but will not switch off when the temp is reached. It is a weird system anyway that was in this house when we moved in, we can only have hot water when the heating is on, so to get past it we have the heating on 1 degree in summer so the heating doesnt come on but the water heats up, so because that isnt working now, we have no hot water, which with 7 kids is a nightmare. I am not a gas/ heating/ plumbing savvy person but I dont think my plumber is either. It has cost us a small fortune already, so am just looking for advice as my plumber says if this doesnt work he doesnt know whats wrong! 
and we really dont want to be having to pay out for a new system, which seems to be all he talks about!
Also the water only heats up when the 3 port valve switch is on manual not auto, if that means anything.
and we really dont want to be having to pay out for a new system, which seems to be all he talks about!Also the water only heats up when the 3 port valve switch is on manual not auto, if that means anything.
