Hi - I have a Potterton Performa 28i combi boiler with a Grasslin time switch and no thermostat (just radiator thermostats).
I have a problem during the operation of the central heating. When the central heating is on and running everything is fine and there is excellent heat from the radiators. When a user switches on the hot water it correctly diverts from the CH to the hot water. However, it sometimes has a problem diverting back to the CH. It seems to just stick on the hot water (the hot water neon stays lit) even after the hot water has been switched off and the burner goes out. I wait for maybe 10 minutes to see what happens, but the boiler just sits there with the fan spinning and with the hot water neon stuck on. If I then open a hot water tap to get the burner to fire up, and then quicky close the hot water tap, it seems to flick back to CH and everything is ok again. However, it does not always seem to be able to do this on its own, and can sometimes take a couple of manual attempts, i.e. turning hot water tap on and off to get it back to CH. This is a annoying problem, particularly at this time of the year!
I had both thermistors replaced about a year ago so it shouldn't be those. Any ideas what could be causing this?
You see when I had the thermistors replaced last year, it took a plumber 2 hours of fault finding to eventually agree with me to try those (since I consulted this site) ending with a large repair bill for very cheap components. Therefore, I would be happy to replace a component if it was a fairly simple job.
Any help welcomed. Thanks a lot.
I have a problem during the operation of the central heating. When the central heating is on and running everything is fine and there is excellent heat from the radiators. When a user switches on the hot water it correctly diverts from the CH to the hot water. However, it sometimes has a problem diverting back to the CH. It seems to just stick on the hot water (the hot water neon stays lit) even after the hot water has been switched off and the burner goes out. I wait for maybe 10 minutes to see what happens, but the boiler just sits there with the fan spinning and with the hot water neon stuck on. If I then open a hot water tap to get the burner to fire up, and then quicky close the hot water tap, it seems to flick back to CH and everything is ok again. However, it does not always seem to be able to do this on its own, and can sometimes take a couple of manual attempts, i.e. turning hot water tap on and off to get it back to CH. This is a annoying problem, particularly at this time of the year!
I had both thermistors replaced about a year ago so it shouldn't be those. Any ideas what could be causing this?
You see when I had the thermistors replaced last year, it took a plumber 2 hours of fault finding to eventually agree with me to try those (since I consulted this site) ending with a large repair bill for very cheap components. Therefore, I would be happy to replace a component if it was a fairly simple job.
Any help welcomed. Thanks a lot.
