whatsoccurring
Member
I have a Glow worm 100 FF about 12 yrs old, 2 Honeywell V4043H zone valves (installed a couple of years ago), a pump always set to its fastest speed.
The boiler wouldn't start 6 days ago. In the few days before this I had heard, rather more often than usual, the sound of a zone valve doing its spring return operation.
I suspected a faulty zone valve or its motor. I found I could manually latch the CH zone valve open, thereby bypassing the roomstat.
This didn't >immediately< turn on the pump as I had expected, but the boiler and pump are working OK now, just when they decide to! I have looked at the boiler booklet, and realise that it is the boiler's circuit board that turns the pump on and off.
I can't understand what is controlling the boiler and pump now. The boiler is coming on for reasonable burn periods with reasonable rests in between, ie it is not operating at its max performance, and it is also varying day by day. Doing well today and house rather cold yesterday.
Can anyone help narrow down where the fault may lie? Thanks.
I am a school technician and can safely do basic electrical testing with a multimeter.
The boiler wouldn't start 6 days ago. In the few days before this I had heard, rather more often than usual, the sound of a zone valve doing its spring return operation.
I suspected a faulty zone valve or its motor. I found I could manually latch the CH zone valve open, thereby bypassing the roomstat.
This didn't >immediately< turn on the pump as I had expected, but the boiler and pump are working OK now, just when they decide to! I have looked at the boiler booklet, and realise that it is the boiler's circuit board that turns the pump on and off.
I can't understand what is controlling the boiler and pump now. The boiler is coming on for reasonable burn periods with reasonable rests in between, ie it is not operating at its max performance, and it is also varying day by day. Doing well today and house rather cold yesterday.
Can anyone help narrow down where the fault may lie? Thanks.
I am a school technician and can safely do basic electrical testing with a multimeter.