ariston micro genus 23mffi lockout probs

[moogwai]

my mate has the above boiler which is locking out when reaching temperature......i went and had a look yesterday but for the 30mins i was there it worked as it should....2 hours later he gave me a call to say it had locked out again!!
I'm thinking pcb has gone but don't want to get one until i've put it out there for your thoughts.

Ive discounted fan,aps, sensors as when you hit the reset button it fires up again without any troubles!!!

 

[wnjswozo]

check where flue meets top of boiler,i,m sure there,s a restrictor that can be removed, also check venturi

 

[moogwai]

check where flue meets top of boiler,i,m sure there,s a restrictor that can be removed, also check venturi

ok thanks mate...would the venturi be a problem though as it fires and keeps going in ch and hw mode until it locks out?

 

[southcoastboile]

Had exact same fault on this boiler, i changed pcb and when i took it out i found a scorch mark on it. Not saying its definitly this causing it but it was on the one i did.

 

[Billy Bob Bob]

take the combustion cover off is it continually sparking?

 

[moogwai]

Very intermittent this one.....not heard nothing since i last went!! But no gasman it didnt carry on sparking with case off. what would cause that fault?

Sent from my GT-I9100 using Tapatalk

 

[warrington]

overheated?? I would check simple things first, i had similar problem on different boiler, and it turned out, between wireless roomstat and receiever there was no connection and boiler was working on override mode.
or you may have faulty detection electrodes.

 

[southcoastboile]

As gas man said about the sparking while main burner on, its a very common fault on this boiler, had it loads of times, its always been the pcb that causes it although i tend to change pcb and probes to be on the safe side, of corse other things can cause it, i.e falty burner, blocked injectors, incorrect min bp but from experience if it keeps sparking while lit it is the pcb