Recent content by HKB

I appreciate this is an old thread, but someone may find this helpful. Fan cycling is likely caused by a fault in the -50V low voltage power supply on the 407677 PCB (located just to the right of relay 1), which energises relay 1, and relay 1 keeps the fan running after the air pressure switch...

Not sure why, but it is overshooting by 0.5C. Today it was calling for heat at one point even though measuring 20.5C with a set point of 20C. I hope it will settle down but I don’t know how adaptive or sophisticated the software is.

So far only one room thermostat in a central downstairs location. The ground floor is semi-open-plan. I’ve started cautiously. I may buy radiator stats later for some bedrooms.

Thanks. I haven’t counted. But the oil setting is a lot less intrusive. It seems to overshoot a little more, but only by 0.5C which is a small price to pay for a quiet life (and perhaps more efficient gas usage on an old boiler). I’ll never know because it’s not a controlled experiment. I would...

My 24 year old Potterton boiler was short cycling after installing the Wiser system. It sometimes fires up and the pump runs for only a few seconds. It also boils up and I suspect short pump times may not help, but this may be unrelated. I initially suspected the overrun thermostat was...