Hi,
I currently have a fully pumped Y-plan open vented system with a Potterton Suprima 80 boiler which has started playing up recently. What's happening is that on some occasions the boiler refuses to turn off. We first notice this when it starts to get too warm in the house - the boiler refuses to turn off even though the room stat temperature has been reached. Also, the water in the hot water cylinder becomes much too hot implying that both the room and cylinder stats are being ignored. Bizarrely, even if the heating programmer (Drayton LPP241) is turned to the off setting the boiler still continues to fire up and run. The only way to get it to turn off is by power cycling the heating programmer at its mains switch off the fused spur.
I was going to replace the programmer but after doing a search for similar problems it seems that the mid-position valve might instead be the cause of problem. Does this seem plausible? Our mid-position valve was actually replaced some time last year but nothing else has been done to the system. So is it better to try replacing the mid-position valve first to see if this fixes the problem? The problem is intermittent right now but is there something I should be looking out for next time it happens to help pin point the exact cause?
I currently have a fully pumped Y-plan open vented system with a Potterton Suprima 80 boiler which has started playing up recently. What's happening is that on some occasions the boiler refuses to turn off. We first notice this when it starts to get too warm in the house - the boiler refuses to turn off even though the room stat temperature has been reached. Also, the water in the hot water cylinder becomes much too hot implying that both the room and cylinder stats are being ignored. Bizarrely, even if the heating programmer (Drayton LPP241) is turned to the off setting the boiler still continues to fire up and run. The only way to get it to turn off is by power cycling the heating programmer at its mains switch off the fused spur.
I was going to replace the programmer but after doing a search for similar problems it seems that the mid-position valve might instead be the cause of problem. Does this seem plausible? Our mid-position valve was actually replaced some time last year but nothing else has been done to the system. So is it better to try replacing the mid-position valve first to see if this fixes the problem? The problem is intermittent right now but is there something I should be looking out for next time it happens to help pin point the exact cause?