Hope someone can give me some advice on a couple of problems I have with my heating / hot water system. I have an un-vented system with a megaflo in my flat. It was installed new ten years ago when the flats were built.
1) Hot Water Pump Keeps Running
This winter, when I have the heating on I have noticed that sometimes the hot water pump keeps running either when the thermostat has clicked the boiler off or the heating timer has turned off.
What used to happen is that if the thermostat temp was reached I would hear it click and the boiler would go off straightaway and so would the pump.
Now, when I hear the click of the thermostat, the boiler may continue firing for 30 odd seconds and then it turns off. If this happens (rather than turning off the instant the thermo clicks) the pump will continue running.
My plumber told me this was normal; that the pump was pushing cold water back to the boiler to cool it down. But I have had the pump continuing to run for three hours after the heating has gone off. When this happens I have turn the heating back on and muck around with the thermostat to try to get everything (the boiler and the pump) to turn off together. This can take a few attempts, during which I can sometimes get the boiler to come on and stay on with the heating switched off.
It seems as if the thermostat, boiler, pump and heating switch/timer aren't communicating properly.
Other things I have noticed are that when the thermostat has clicked off and the pump keeps running, the boiler may fire up a few more times in the next half hour for about 30 seconds each time and then go off (the pump keeps running).
2) Recharging Air Bubble on Megaflo (model Heatrae Sadia - CL170)
I have to recharge the air bubble in the megaflo every 30 days (the overflow begins to drip when the hot water is on).
My understanding is that this should not need to be done more than around twice a year, and when I first moved in ten years back I used to do it every three/four months, so I clearly have a prob.
Plumber has suggested he either drains the tank fully or I get a new one.
Any advice? Does it sound like I need a new megaflo? The only other info I can give is that the hot water is quite cloudy these days (it does clear a few seconds after it comes out of the tap) but I understand this is sometimes common with un-vented systems.
Any advice would be greatly appreciated.
1) Hot Water Pump Keeps Running
This winter, when I have the heating on I have noticed that sometimes the hot water pump keeps running either when the thermostat has clicked the boiler off or the heating timer has turned off.
What used to happen is that if the thermostat temp was reached I would hear it click and the boiler would go off straightaway and so would the pump.
Now, when I hear the click of the thermostat, the boiler may continue firing for 30 odd seconds and then it turns off. If this happens (rather than turning off the instant the thermo clicks) the pump will continue running.
My plumber told me this was normal; that the pump was pushing cold water back to the boiler to cool it down. But I have had the pump continuing to run for three hours after the heating has gone off. When this happens I have turn the heating back on and muck around with the thermostat to try to get everything (the boiler and the pump) to turn off together. This can take a few attempts, during which I can sometimes get the boiler to come on and stay on with the heating switched off.
It seems as if the thermostat, boiler, pump and heating switch/timer aren't communicating properly.
Other things I have noticed are that when the thermostat has clicked off and the pump keeps running, the boiler may fire up a few more times in the next half hour for about 30 seconds each time and then go off (the pump keeps running).
2) Recharging Air Bubble on Megaflo (model Heatrae Sadia - CL170)
I have to recharge the air bubble in the megaflo every 30 days (the overflow begins to drip when the hot water is on).
My understanding is that this should not need to be done more than around twice a year, and when I first moved in ten years back I used to do it every three/four months, so I clearly have a prob.
Plumber has suggested he either drains the tank fully or I get a new one.
Any advice? Does it sound like I need a new megaflo? The only other info I can give is that the hot water is quite cloudy these days (it does clear a few seconds after it comes out of the tap) but I understand this is sometimes common with un-vented systems.
Any advice would be greatly appreciated.
