BAXI 105 HE No Reset

[Vardo]

My Baxi 105HE suddenly stopped working.
I have power to the unit and and the only light is the Green standby light.
I have drained the radiators and re-pressurised the system to 1 bar.
I have tried to RESET when I have turned the hot-water tap on and again when I have put a call for central heating.
As I say, regardless of the amount of time I keep the switch in the reset position, I can't get the boiler to fire up.
If any other information is required for the problem to be diagnosed, please let me know.
Thank you in advance for any information.

 

[Agile]

They usually need about 10-20 seconds to be reset but that's normally only needed after the PCB has been changed.

I expect that you have a fault. It could be the PCB ! But it could be many bother things which an RGI could check.

Tony

 

[petit_pablo]

Your boiler wont need resetting if there are no red lights showing.

Does the heating work?
Do you get the heating or tap lights come on when you try and fire it up?

 

[Vardo]

I have now found that if I turn the hot water tap on and then manually flick the micro-switch on the three way diverter valve, the boiler fires up and I get hot water (I have to do this each time I want hot water). When I put a call for central heating and keep the same switch pressed, the boiler will fire up but stops when I release the switch.
Again, any advice will be greatly appreciated and if any other information required, just ask.

 

[petit_pablo]

Which microswitch are you meaning? The one on top of the valve or the one at the front?

 

[Vardo]

I've just checked, it is the one at the front. I hadn't noticed the other one.

 

[Agile]

Diverter valve has failed.

Bu it would normally still work on heating.

Tony