HELP PLEASE!Dead boiler(Simi 90)

[gnvqsos]

The boiler will not fire up either for DHW or CH.The pump does not start when CH is on so I presume this may need to be replaced.The fault finding guide suggests this.However on the other hand it may be a new PCB.
The only sign of life is the green neon and the click of the microswitch when the hot tap is opened.Does anyone have any experience of these so I can get the necessary part locally for my CORGI friend to fit.

 

[kev_1911]

does the fan run? no fan = no fire on this boiler so start there,and if you have a corgi mate to fit the bit then he should be able to tell you exactely what bit you need to buy for him to fit?

 

[gnvqsos]

NO the fan does not run.As the boiler is over 10 years old then the fan may well feel tired;thanks for the quick reply Kev

 

[gnvqsos]

I have had a second inspection and the pump is not running.Am I right to believe the pump is activated before the fan?If this is the case it suggests the pump is faulty.

 

[kev_1911]

i may be wrong on this,however i think the sequence of operation for sime 90 is fan/pump/ignition do you have the manual for your boiler? if so check in the fault finding charts.

 

[gnvqsos]

I have the script here and its reads pump-fan -ignition so it points to the pump does'nt it.What do you think?

 

[barryauid]

If it should be pump first then you need to know if its got volts to it first,if no volts then pump is probably ok.
Does boiler have a overheat reset,
have you got pressure over 1 bar on the gauge?

 

[gnvqsos]

Thanks barry!I have tried to reset heat stat but already depressed.Also there is ample pressure so it looks like a new pump needed

 

[gnvqsos]

Just rung Corgi pal and he seems to think it might be air pressure switch.Any second opinion?It does not square with fault-finder but I do respect his opinion based on previous experience.

 

[gnvqsos]

Now resolved;having got parts it turned out to be a blown fuse(100mA) and there were two inside control box.