PCB blown

[littlesaur]

I have an Ideal Minimiser SE which is approx 3 years old. Three weeks ago the PCB (PCB 41) blew and was replaced. The fuse in the switch that powers the boiler also fused. This fuse has now gone again and we are without heating and hot water again. It is a 3 amp fuse - could we put a 5 amp in?? Secondly, if it is the PCB that has gone again, what could be causing this? The house is only 3 years old and we have had nothing but trouble with the heating/hotwater/boiler. Should I cut my losses and get a new boiler? Please help!!

 

[PEDANTICVINDICTIVEMAN]

Get a new house.

 

[kevplumb]

1 read the post at the top
2 what happened before it went bang ?
pedantic love you bye bye

 

[littlesaur]

Noticed that the heating hadn't come on so went to see if boiler had locked out. No fan noise. Turned the boiler off and then on again by turning the switch inside the boiler to 0 and then back to 5. Nothing happened. Then noticed the programming unit had gone off as the fuse had blown. Changed the fuse, turned the heating on and the fuse immediately blew again. Will look 2morrow to see if PCB has gone again but am worried there is some underlying cause. Help! This is becoming expensive.

 

[kevplumb]

not a definitive opinion but have the gas valve checked

 

[littlesaur]

should we get an engineer to check the gas valve or is it something we could do? What would we need to look for?

 

[kevplumb]

if you can use a meter check the solenoid for continuity or short

 

[BDL]

Check this-

You will probably have condense leaking from the ignition probe gasket. You will see white staining. The condense will run down the wiring loom and through the plastic connector into the pcb!

Look at the pcb and you will see staining, lift the pcb out and you will see white condense marks on the metal pcb housing.

Before doing anything else get the gasket replaced.

 

[kevplumb]

go for it i bow to the opinion of one who knows

 

[littlesaur]

Bizarrely, we have now taken out the PCB 41 and replaced it with the old PCB37 which we replaced because we were having problems with lockout and it only gave one ignition attempt. The PCB 41 gives 5 and a longer pre purge. Anyway, the PCB 41 was dampish. We have put the PCB 37 back and the boiler is now sparking (although sadly not igniting but its not that cold today). Hopefully, I can get an engineer out tomorrow. Any further help gratefully received..