Dunkirk quantum 90 not staying Lit

wilson95

I have a dunkirk quantum 90 it runs through the cycle fine then when it get to light only lights for one second then shuts off and starts the cycle over I installed a new Igniter and air flow switch I and get it to stay lit only if I put a jumper wire on the air flow switch 

clammy

if your able to get it running by jumping the air switch I would guess you have either a blockage of your exhaust or air inlet piping or a partially clogged heat exchanger . Just as a wag but I would gather that unit has a few years on it ?I do hope if your operating it w a jumper that you have a co dect in the boiler room and main living area . When was the last time the unit received a proper servicing and combustion testing ? Peace and good luck clammy

wilson95

My exhaust and intake pipes are clear 

Ironman

You’re condensate drain is clogged.

wilson95

I cleaned it out still tuning the same cycle 

EBEBRATT-Ed

@wilson95

take the tubing off the air flow switch and make sure it's clean. You should have it checked and serviced.

You either have a bad switch or something is plugged or you combustion is way off

Ironman

Did you clean the condensate trap and the sediment trap at the bottom of the exhaust pipe?

wilson95

Yep and I cleaned every pipe out 

twistedmetal

Did you ever figure this out?