I have a confusing problem with my central heating system, and any assistance would be gratefully received.
System is a fully pumped system fired by a Potterton Netheat back-boiler. When the system is activated, all seems to be correct: 3-way valve turns, pump starts and boiler fires. (Very) Hot water starts to flow into the 3-way valve and flows into the correct exits from the valve, depending upon CH/HW selection. The radiators normally get hot and the hot-tap water starts to heat.
However, after a period of time things normally start to go awry. Although all components seem to be running OK still (pump running, boiler firing), the water into the 3-way valve is not as hot as it should be. The radiators are warm, but not hot, and the hot water is the same. As the rads/water is not getting as hot as it should, the thermostats never turn the system off and the boiler/pump run all day to no effect (boiler turns itself off when thermal cut-out activates, then starts up again when cooler). System can be forced to start working again by de-selecting both HW/CH at the controller, leaving for a few minutes and re-starting everything.
I’ve tried bleeding radiators, but nothing comes out so I’m assuming that there’s no airlocks, but I’m not sure what else to try.
The last thing that I did to the system was flush with Fernox in March (but didn’t put in a treatment upon re-filling system), and system seems to have been running OK just on HW over the summer. Problem just seems to have started now we’re using the CH in earnest.
Other posts talk of noises coming from their system – this problem is causing a noisy whining sound to come from the missus, so any help would be gratefully received.
System is a fully pumped system fired by a Potterton Netheat back-boiler. When the system is activated, all seems to be correct: 3-way valve turns, pump starts and boiler fires. (Very) Hot water starts to flow into the 3-way valve and flows into the correct exits from the valve, depending upon CH/HW selection. The radiators normally get hot and the hot-tap water starts to heat.
However, after a period of time things normally start to go awry. Although all components seem to be running OK still (pump running, boiler firing), the water into the 3-way valve is not as hot as it should be. The radiators are warm, but not hot, and the hot water is the same. As the rads/water is not getting as hot as it should, the thermostats never turn the system off and the boiler/pump run all day to no effect (boiler turns itself off when thermal cut-out activates, then starts up again when cooler). System can be forced to start working again by de-selecting both HW/CH at the controller, leaving for a few minutes and re-starting everything.
I’ve tried bleeding radiators, but nothing comes out so I’m assuming that there’s no airlocks, but I’m not sure what else to try.
The last thing that I did to the system was flush with Fernox in March (but didn’t put in a treatment upon re-filling system), and system seems to have been running OK just on HW over the summer. Problem just seems to have started now we’re using the CH in earnest.
Other posts talk of noises coming from their system – this problem is causing a noisy whining sound to come from the missus, so any help would be gratefully received.
It sounds like the boiler is at fault, possibly locking out if its electronic ignition.