Baxi boiler instantly blowing 3amp fuse!

[Highlagon]

i have a Baxi WM 531 RS with an fault that causes the 3amp fuse to blow instantly when connected.

All the parts external to the boiler are fine and operating.

I need a systematic procedure to check want item from the boiler is causing the fuse to blow.

This issue started some time ago and intermittently blow the fuse after the boiler operated both hot water and central heating.

But now the boiler is not operating at all now and the the fuse is blown within .5 second.

Also once the repair procedure is identified a service engineer in the Brighton area is required, if anyone can make a suggestion.

Thanks.
David

 

[PrenticeBoyofDerry]

There are number of reason that the external supply fuse can blow.
Is there any damage to the supply cable, has there been any water ingress to the appliance.
Other than that you are looking at internal components, probably best getting an engineer out to it.

 

[Highlagon]

Cable is fine and no one water issues.

Just wondering what are the likely systematic causes to check them in order.

Thanks.

 

[PrenticeBoyofDerry]

It could be the PCB, then next would be likely pump or fan.

 

[mattylad]

As above, I would double check the fan, check no water has been able to get onto the windings from an either badly fitted flue or horizontal rain being blown into it.
(My experience had a fan blow 3 times due to this - but it wasn't a baxi)

 

[Agile]

I don't understand why you say you want to identify the problem yourself and only then call an RGI.

The normal procedure would be to call the RGI to identify the problem for you.

Makes me think that you really want to do the repair yourself.

Seems to be little point checking the fan on your boiler model. I don't think that it has one. Apart from the fact that it would be part of the gas combustion system and so not suitable for DIY repairs.

Tony

 

[gas112]

Pmsl fan and PCB on a baxi rs really !

 

[gas112]

First port of call would be to check the motorised valves have not been leaked into, then disconnect the pump wires to disregard that