potterton promax 28 he fault

[david4924]

having problems with a potterton promax 28 he, no fault codes showing call for heat and nothing happens only tempreture displayed. put hot tap on and hot water light comes on but its only the pump that kicks in then nothing else happens. when you reset it the fan kicks in for pre purge so fan is ok. was thinking the p.c.b but an expensive part so want to be sure, anyone ever came across this?

 

[andyg0507]

have you tested the fan for resistance, and also check aps.

 

[david4924]

no because if fan is not running then how can the aps be at fault ? there is no power going to fan.

 

[andyg0507]

having problems with a potterton promax 28 he, no fault codes showing call for heat and nothing happens only tempreture displayed. put hot tap on and hot water light comes on but its only the pump that kicks in then nothing else happens. when you reset it the fan kicks in for pre purge so fan is ok. was thinking the p.c.b but an expensive part so want to be sure, anyone ever came across this?

you stated fan was ok

 

[david4924]

i just meant that fan hadnt ceased and was able to run as when i reset the boiler the fan automatically comes on fur 2-3 seconds to pre purge. but when call for heat or hot water fan does need even attempt to run.

 

[andyg0507]

first thing first then, have you checked pump?

 

[david4924]

yes pump is runs then nothing else happens and no fault codes.

 

[andyg0507]

fan is next port of call then, just listening to boiler may not be enough, although no fault codes.

 

[david4924]

i would have thought that if the fan is not getting signal from p.c.b ie power supply, you would then think this is a faulty p.c.b?

 

[andyg0507]

pump,fan,aps,igntion, if no fault codes then possibly pcb also, but unless you check these using your multi meter how do you know how far its getting in its sequence?