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armourer

Plumbers Arms member
Plumber
Gas Engineer
Jun 23, 2011
571
115
43
Midlands
Member Type
Heating Engineer (Has GSR)
Not often I have to post on here but I was recently moved onto another contract so not familier with this boiler.

I went to a job on Friday first off pump runs but nothing else.
I then freed the APS and it now lights the pilot but no main burner.

I get pilot light, boiler still continues to spark then shut down (no power to gas valve solenoid).

Im thinking its not seeing the pilot light so is not lighting main burner.

Any pointers on this model apart from the fact its a bag of nails?
 
Not got the details to hand, but I think this is the one with the condensate señor which shorts to earth and stops the burner firing. Disconnect the earth and see if it fires. Sometimes they remain damp giving the impression the condensate trap is blocked.
 
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What you want to do it check the NTC sensor on the primary flow. This may be giving the problem where just the pump runs.

The sparking will most likely be the connection to the condense trap for the ignition/rectifcation lead. Cut them off the trap and connect them together by stripping the white outer covering off and a connector block. The boiler should light first time and stay lit now. If you order the new lead, it will come as one, not with the condense trap connections. So you could see it as not much point. This is all assuming you're working on the mk 1 with the red Honeywell ignition PCB on the gas valve.

The mk 2 does away with the trap connections anyway, has no red Honeywell PCB on the gas valve and a separate rectification probe. Most likely cause with these is water in the bottom of the combustion chamber, which is also a common problem with the mk 1 an usually stems from the heat exchanger connection on the right hand side. The rubber seals are rubbish.
 
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What you want to do it check the NTC sensor on the primary flow. This may be giving the problem where just the pump runs.

The sparking will most likely be the connection to the condense trap for the ignition/rectifcation lead. Cut them off the trap and connect them together by stripping the white outer covering off and a connector block. The boiler should light first time and stay lit now. If you order the new lead, it will come as one, not with the condense trap connections. So you could see it as not much point. This is all assuming you're working on the mk 1 with the red Honeywell ignition PCB on the gas valve.

The mk 2 does away with the trap connections anyway, has no red Honeywell PCB on the gas valve and a separate rectification probe. Most likely cause with these is water in the bottom of the combustion chamber, which is also a common problem with the mk 1 an usually stems from the heat exchanger connection on the right hand side. The rubber seals are rubbish.

I've had this same problem with the thermistor come to think of it
 
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pulling one out tommorrow 🙂 according to custard it exploded today, water everywhere. I was due to replace it next week!
 
Thanks for the pointers all.
I did play about with the condensate interupter but I didn't know I could just link it out.

I am back on that contract again tomorrow in Stoke so I will go armed with a thermister in my pocket too just in case.

I could not call technical as it was gone 6 on Friday night. Hopefully I will attend at a more reasonable time.
 
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pulling one out tommorrow 🙂 according to custard it exploded today, water everywhere. I was due to replace it next week!

Probably the AAV. At the end of the day, they're a throw away boiler, put them in and expect them to last 6 years, then throw them away. I have worked on them quite a lot over the past few years, most of them are being replaced now fortunately. I used to attend several a day, but have only seen one in the past few weeks, so my job is getting slightly easier.
 
Not often I have to post on here but I was recently moved onto another contract so not familier with this boiler.

I went to a job on Friday first off pump runs but nothing else.
I then freed the APS and it now lights the pilot but no main burner.

I get pilot light, boiler still continues to spark then shut down (no power to gas valve solenoid).

Im thinking its not seeing the pilot light so is not lighting main burner.

Any pointers on this model apart from the fact its a bag of nails?
if its sparking,not seeing detection and locking out you have reversed polarity,detection probe or lead issues(very likely connections are tat)or a duff pcb
 

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