Potterton gold :(

[plumb_know]

Hi Everyone,

Potterton gold Heat only driving me mad, would appreciate if anyone has any ideas on this one as boiler cutting out after 10-15secs. Phoned baxi 4 times but nothing seems to be working.

Called to boiler not firing, Fault code on LEDS is ignition lockout.

Take cover of burner and find all seals gone and not been serviced in 5 years. carry out a service cleaning burner, condense trap, replacing combustion door with new seals & new electrode kit. Fire up and burns lovely but still goes out after 15secs.

Checked: tightness test, boiler polarity, checked no water on trap connectors, tried firing it without white cable from electrode connected to trap, checked getting over 18mbar working pressure (it does go to 17mbar on initial lighting for 1sec but then stabilises at 18.5mbar), replace all 3 electrode leads, tried a new pcb, cleaned out small pipe from top of gas valve (on baxi advise), getting 205DV to gas valve. tried to check to see if gas valve cutting out (on baxi advise) believe this is all ok as 205v dc to gas valve while operating hear valve close and no DC current to gas valve at that time and inlet pressure goes back to standing. also checked continuity on all electrodes to cable ends.

Each time i call baxi they are saying that what i have done should have cured it.
Any one else think of any tests i could carry out?? could it just be i picked up a faulty PCB? at the moment i have left it with the customer i will get another pcb and see if that work but have no idea where to go if it does not??

appreciate any help

 

[ShaunCorbs]

any flow and return thermistors ? sounds like either not sensing flame or cant get the heat away but as youve replace the electrodes

you tried it just on hot water?

 

[plumb_know]

yes there are but baxi said the thermistors would not kick in that quick, do you know what ohms readings i should get from them when cold (12k ohms ?? )

thanks Shaun

 

[ShaunCorbs]

should be listed in the manual but rough guidance

Temperature (degrees C)	resistance (ohms)
0	35400
10	22500
20	14700
25	12000
30	9835
40	6712
50	4672
60	3311
70	2388
80	1749
90	1300
100	980
110	749

 

[Burger]

Fault on gas valve? Burner ok? Correct voltages? Loose wire? Correct spark gap? If it is overheat or related is pump defective/correct voltage?

[automerge]1568414272[/automerge]

any flow and return thermistors ? sounds like either not sensing flame or cant get the heat away but as youve replace the electrodes

you tried it just on hot water?

If it were, would it not be overheat, rather than ignition lockout?

 

[ShaunCorbs]

If it were, would it not be overheat, rather than ignition lockout?

Don’t know, as he’s ruled out the electrodes

Either ntc or heat issues in my mind but could be wrong

 

[plumb_know]

Fault on gas valve? Burner ok? Correct voltages? Loose wire? Correct spark gap? If it is overheat or related is pump defective/correct voltage?

[automerge]1568414272[/automerge]


If it were, would it not be overheat, rather than ignition lockout?

i Do not think its over heat as it the fault code on the boiler is ignition lockout also its 10/15 secs before cutting out which i dont think the boiler would over heat that quickly, no sound of air bubbles in the heat exchanger or kettling.

what checks can i do on the gas valve apart from seeing its getting 240dc & that it is passing gas??

also what correct voltages do you mean?? i have checked polarity, gas valve, continuity of electrode cables, electrodes are new also the boiler is not continuing to spark once it has lit suggesting boiler has recognised boiler has lit.

I have checked over the cables pressing them all to ensure they are in.

Thanks for the help everyone

 

[Burger]

what checks can i do on the gas valve apart from seeing its getting 240dc & that it is passing gas??

also what correct voltages do you mean?? i have checked polarity, gas valve, continuity of electrode cables, electrodes are new also the boiler is not continuing to spark once it has lit suggesting boiler has recognised boiler has lit.

I don’t think there are any other checks on tha gas valve, other than resistance of the pins? The correct voltages I mean are you getting 240vac to your live and neutral?