Combustion blower won't turn off

[serenelake-in-tahoe]

Hello I have a napoleon NPS40 and the combustion blower won't turn off. When it has been off for hours and totally cold, it is running. I unplugged it and replugged it in and it runs. I tried to check the low limit switch thinking that it was thinking the stove was overheating and thus turning on the blower. It seems to have a complete circuit when checked with a meter. I disconnected the wire to it breaking the circuit but the blower stayed on. Any ideas how to trouble shoot this?

 

[ARC]

Any ideas how to trouble shoot this?

Have never seen or worked on this stove, wiring is not the same as other stoves, so take anything I suggest with a grain of salt.

Check to see if your igniter is staying on just hold your hand close do not touch it.

 

[serenelake-in-tahoe]

No the igniter is turning off. I did check that. Thanks. I'm starting to wonder if this could be the "power control relay"? If this is not caused by some switch or sensor being bad then the catch all is that little bit of circuitry.

 

[ARC]

For anyone else wanting to look at wiring diagram

 

[serenelake-in-tahoe]

I stand corrected. I checked the igniter again and it was on. Always on! So it must be the power relay. Its funny I checked the igniter at first but I think it was bad so I "thought" it was off. I've ordered a new power relay and hopefully this will fix it.

 

[ARC]

Could be a shorted igniter switch too, W660-0054 IGNITION SWITCH 120°F (60°C) but like I said your wiring is different then most brand stoves. igniter switch could be stuck closed. It is the 120° snap switch on the exhaust channel. Hopefully it is the power relay and that solves your problem.

 

[serenelake-in-tahoe]

Could be a shorted igniter switch too, W660-0054 IGNITION SWITCH 120°F (60°C) but like I said your wiring is different then most brand stoves. igniter switch could be stuck closed. It is the 120° snap switch on the exhaust channel. Hopefully it is the power relay and that solves your problem.

Humm. How does that work? If it reaches 120 it closes? But that would tell the unit that it is too hot and so the combustion fan turns on? Also isn't that supposed to turn the igniter off too? I should be able to test it but unattaching the wires?

 

[ARC]

Switch is normally closed/on when stove is started power goes to igniter when switch gets to 120 it opens/off and turns igniter off. Did some searching on here. Not sure if the timer they talk about is the power relay? I think it is the same switch.

Bad switch melted and timer/power relay?

https://www.hearth.com/talk/threads/napoleon-nps40-ignition-switch-fix.69378/

Below link says power relay is problem

https://www.hearth.com/talk/threads/napoleon-nps40-please-help.71985/#post-907613

 

[serenelake-in-tahoe]

Hey thanks great older threads. They were really interesting. My ignition switch is okay. I think I've always kept my unit clean or maybe the design is better but that switch looks great and doesn't see like it is get melted.

I am pretty sure at this point it is the power relay. Just waiting for the replacement to come in so I can see if it fixes all of my issues. Thanks again!