quadrafire mt Vernon vacuum switch error

[agforest]

I decided to switch from wood heat to a pellet stove. I took out the Kuma wood classic in exchange for a 2017 Quadrafire Mt Vernon on Craigslist for $1500. Looks to have not much use. Anyway, I installed it and turned it on, set it to manual.
Start up
SS Low
SS medium
Then Vacuum SW error and it starts to power off.
Does this Every time
So, I bypassed the switch and it works fine.
I took the vacuum switch off and measured ohms. If I very gently suck on the tube....like hard let any suction, the switch turns on and when I very gently blow, the switch turns off. Don’t know if the vacuum switch is bad but it appears to function.

the vacuum tube is clear, the nipple that it connects to on the feed tube is clear.
The gaskets on both the ash pan and the glass door appear to seal very well. Both are very tight.
It’s driving me crazy. I feel like I got snookered by the seller but I’m determined to fix it myself and enjoy not splitting and stacking 6+ cords of wood each year.
How can I fix this vacuum switch problem?
what should I test next? I don’t want to call out a technician if I can help it because that will just defeat the purchase of saving money by purchasing a used stove.

 

[Ssyko]

Pull the combustion blower and clean and inspect the fan blades, blow out the motor frame/housing with compressed air and lube it if possible. You may need a new gasket. Go to the quad site and dl the manual and do the annual cleaning on it. See if that helps with the vacuum issue.

 

[agforest]

I thoroughly cleaned the combustion blower early this morning. With a tooth brush and I vacuumed out all the sooty material in the passageway leading to the blower. The gasket is in great condition. Same vac sw error. I do smell some of the smoke from the pellet combustion. Not much but I smell it. I don’t see any smoke. Is this normal? Anyway, I read the manual about cleaning and will clean some more but the unit is extremely clean as it stands. What should I try next? Is it possible that the vacuum switch could be bad? I might order one but I suspect that once I swap the parts I’ll have the same issue.

 

[agforest]

I think that I’m going to take the fire pot out after work today and inspect that gasket and replace if necessary. I’m also going to order new gaskets for the front door and ash pan and replace with the high temp black gasket sealer on back. Can’t hurt huh? I’m going to get the air compressor and scrape/blow out/shop vac everything I can stand tonight.
Another thought: the exhaust pipe I installed is new. It goes straight out of the back of the stove, through the wall, and up 3’ out of the clean out T. It’s the $200 kit from Lowe’s. I used red RTV on the portions of pipe (adapter/6”/12” piece that exits the stove. I slipped that stuff inside and outside very liberally. Can the draft, or lack there of when starting the stove cause vacuum issues?

 

[kappel15]

No, as the exhaust fan causes the draft, and the vacuum in the firebox, that shuts the vac switch connection, allowing power to the auger. That new of stove, shouldn't need a door gasket. You can do the dollar bill test and see how good it is. Stick a bill in door and close it. See how hard it is to pull bill. Also, if there is no fire stain past area on door that hits gasket, it is good. One major area people miss when cleaning their stoves, is the two openings at bottom of heat exchanger fins. The area between them is open. kap

 

[agforest]

The door gasket failed the dollar bill test and the ash pan door failed as well. I bought new gaskets at Andy’s Heating and Cooling in Coeur d’Alene and I just replaced both gaskets and am waiting for the stove to turn on. I also ordered a new vacuum switch just so I’d have one. I hope that I can reply that it works!

 

[agforest]

SOLVED
The vacuum switch is indeed bad. When I blow into it and break the circuit and then plug the hose in, there is a vacuum that immediately completes the circuit. BUT if the switch is in a certain position, it turns off. But if flat on either side, and plug it in, the vacuum pulls the circuit closed and it works. So, I have the vacuum switch hanging in a position where it works and so far no error codes for an hour!! The new vacuum switch in order. I’ll update when I get it in and install it.
Btw, the door seals were pretty tight but not water tight like a frogs butt so replacing the seals probably didn’t hurt.

 

[kappel15]

Glad you got it figured out and are up and running. Stay warm. kap

 

[KL0828]

I wanted to attach a comment here for anyone else seeking help with this. I encountered a mystery with my vacuum switch after moving into a house with a pellet stove that hadn't been in use for at least a couple years. Please be sure to CLEAN THE CHIMNEY/VENT OUTSIDE YOUR HOME and within the elbow that hoes to the vent after the exhaust/combustion blower. I discovered some soot and what looked like grass as if a bird built a next in the vent. Removed it and cleared the vent pipe with a brush and no more vacuum switch error.