Hi all:
my central heating boiler kept overheating (cut our switch tripped) and I eventually realised the pump overrun switch wasn't working. I replaced it and all "seemed" fine. Then the mid postition valve didnt appear to be working (had failed 2 years previously but i only replaced the motorised head) so I drained the system and have replaced the valve body. when refilling I emptied the header tank (sorry if terminology wrong) and there was at least an inch of sludge in it. The mid position valve replacement made no difference to the water in the radiators feeling cold the further you get from the pump. If I stop the pump running I can hear air trying to flow back up the pipe past the pump, if I switch the pump from speed 1 to 2 to 3 I can hear a change in the speed of the pump. The system has over years always had air in one particular (first I think) radiator. I refilled with a corrosion inhibitor, and had noted when i drained the system for the above valve repair the water looked clear. There is currently no air in any radiator, and the hot water seems fine (extremely hot) The boiler is switching off and on ok, but if I turn the water temperature up, the boiler overheats.Its almost like the central heating pipe is blocked, or maybe the impellor on the pump is blocked or worn and unable to push the water around?
Does anyone have any ideas before I go spending more money on a new pump?
my central heating boiler kept overheating (cut our switch tripped) and I eventually realised the pump overrun switch wasn't working. I replaced it and all "seemed" fine. Then the mid postition valve didnt appear to be working (had failed 2 years previously but i only replaced the motorised head) so I drained the system and have replaced the valve body. when refilling I emptied the header tank (sorry if terminology wrong) and there was at least an inch of sludge in it. The mid position valve replacement made no difference to the water in the radiators feeling cold the further you get from the pump. If I stop the pump running I can hear air trying to flow back up the pipe past the pump, if I switch the pump from speed 1 to 2 to 3 I can hear a change in the speed of the pump. The system has over years always had air in one particular (first I think) radiator. I refilled with a corrosion inhibitor, and had noted when i drained the system for the above valve repair the water looked clear. There is currently no air in any radiator, and the hot water seems fine (extremely hot) The boiler is switching off and on ok, but if I turn the water temperature up, the boiler overheats.Its almost like the central heating pipe is blocked, or maybe the impellor on the pump is blocked or worn and unable to push the water around?
Does anyone have any ideas before I go spending more money on a new pump?
