my vokera boiler keeps blowing the hot water and heating fuse, weve had the engineer out several times and they kept replacing the fuse, last one said it was a uild of up calcium around it even though i stay in soft water area, mentioned it could be my supply pipe, had to get council out to test water and if its no that then i could be looking at having to get a new boiler

the woman, October 2008

Phone the free Vokera technical helpline or email them for a clue to give to your repair man. Or get him to phone them in your presence (he may feel it beneath his dignity to ask for help),

FWIW At a wild guess I would say a shorted diode in the bridge rectifier on the secondary of the transformer that power the PCB. But it is just a guess, see if the fuse blows with the pump disconnected, the fan disconnected etc to get an idea of whats doing it (the mains should be going through an earth leakage breaker if you are working near live bits) ;you have to be careful as you could electrocute yourself or break something expensive with a careless move. If you are good enough at electrical work you could try putting an ammeter in the feed to the pcb power, the pump power and the fan power to find the culprit. Beware though, lethal voltages, it may be an idea to try a different repair man. I doubt if your boiler is so furred up it is stalling the pump and blowing the fuse.

c, October 2008