Worcester oil 18/25 no central heating

[Oh752]

Hello all

Appreciate your help please. I have hot water, no central heating on an oil boiler combi

1. Diverter valve is fine
2. Heating comes on sometimes on demand, but generally doesn't
3. Room stat seems fine... it clicks on, but the boiler won't fire for heating
4. Pressure is ok
5. Heating stat seems ok. Resistance is minimal across the terminals
6. Reflowed the solder on the pcb just on case of a dry joint

Anything I can check before I change the pcb please?

Cheers

 

[oilhead]

I take it that before running loose with the soldering iron on the PCB, you used a multimeter to check the various tests in the fault finding guide.
If not, I suggest you do so. There is a logical sequence to follow and will identify the source of your problems. I would be very surprised if you had a faulty PCB, but I hope your soldering has not compounded a problem.

 

[Oh752]

Hi

Thanks for the response. Yes I did...

Anything else come to mind please?

 

[martyndc88]

What timer is fitted? Are you getting 240v back to LR on the PCB? What diverter is fitted?

 

[oilhead]

If you are confident that the fault finding checks point to a PCB, then replace it, but I would be more inclined to suspect a faulty diverter valve switch on an intermittent problem such as yours, especially if it is the Drayton unit.