When the boiler fires up it throws the main electrics trip?
It does it just as the boiler appears to light.
Please can somebody tell me if it is a boiler problem or perhaps the electric timer?
It's a boiler problem - not the timer. I would guess that the solenoid operated gas valve is defective and shorting to earth - plan for an expensive fix - I would think in excess of £300.
Sorry...
January 2016
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