boiler problem

minty247

Hi.
I'm having an issue with my boiler. The other day the heating came on when the timer was off. I could see a slight flicker on the power light on the timer. I suspected the timer was faulty so i replaced with the same model. I just copied the wiring from the old one. 2 red and 2 blue from the timer. I know it has a permanent live to the boiler as it is a combi oil burner. However the timer has worked fine for the last 7 years with no issue, so i don't think its anything to do with the wiring. What could cause this to happen. I noticed the power light is illuminated fully now after i swapped the timer but the timer is in the off position.I had an issue last year similar to this. The heating was on but the timer was off. However i had no light on the timer. It turned out to be a faulty non return valve on the DHW (domestic hot water). It was allowing the DHW back into the CH system. The boiler is a grant combi condenser only 2 yrs old.

aujopimur

You have the live and switched connections mixed up, switch the 2 red wires at the timer.

minty247

aujopimur wrote: »

You have the live and switched connections mixed up, switch the 2 red wires at the timer.

I switched them on the day and still had the issue. Could it be a frost stat issue and this would override the system

DoneDL

Yes a faulty frost stat will overide the contols as will a faulty zone valve.

briano101

Hi everyone .just have a problem with my BAXi gas boiler.
The system will fire up but after 1-2 mins the burner will shut down and leave just the pilot light on. Any ideas?

I don't think it is the PCB as this was replaced last year during the heavy snow. Any simple checks I could do before i call in the plumber??

thanks

Billy Bunting

check the pump is running