Pressure switch

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Daniel75

New Member
Feb 24, 2018
4
King
Ok so I’ve had this king pellet stove for a couple of years. It’s worked great up until recently. My wife calls me at work and tells me she turned it off because the house was filling with smoke from it. Ok, so when I got home. I cleaned it vacuumed it out. Checked to make sure nothing was blocking the smoke from leaving correctly. Then I tried to start it up again, nothing. The draft fan just runs continually. Did so research found out it was my pressure switch. Ordered a new put it in, same thing. Can u guys help me out here? I’m at a loss.
 
So what happens exactly when you try to start the stove?

Do pellets drop? Does the auger turn? Do the fans come on?

We need more info.
 
Check the tubing that goes from the switch to the exhaust duct for a blockage or crack that could cause it to leak. Also check the fitting at the exhaust with a wire to see if it's blocked.
Ron
 
When I power plug the stove into the electrical outlet the draft fan only comes on and runs until I unplug it again or reset the control board back to factory default.
Auger doesn’t turn no pellets drop and the draft fan is the only one that comes on.
 
Sometimes new pressure switches are bad out of the box. I had that happen to me. I had to buy 3 new ones to get one that was reliable. They are cheap, sensitive parts.

But let's trouble shoot the stove a little more before we keep throwing parts at it. Does your stove give you any trouble codes? What does the owners manual say about it?

Also, what caused the stove to smoke up the house in the first place? Could it have been a power surge that messed up the main board? Is your stove on a surge protector?

Hopefully it is just a bad pressure switch. If you figure out the part number and maker, you can buy them cheap without going thru the dealer.
 
Sometimes new pressure switches are bad out of the box. I had that happen to me. I had to buy 3 new ones to get one that was reliable. They are cheap, sensitive parts.

But let's trouble shoot the stove a little more before we keep throwing parts at it. Does your stove give you any trouble codes? What does the owners manual say about it?

Also, what caused the stove to smoke up the house in the first place? Could it have been a power surge that messed up the main board? Is your stove on a surge protector?

Hopefully it is just a bad pressure switch. If you figure out the part number and maker, you can buy them cheap without going thru the dealer.
I have a harmon P43 and my pressure switch has male spades with 2 female spades plugging into it. I just by passed it making a short piece of wire with 2 male spades completing the circuit
 
I tried just putting a wired in place of the pressure switch. The stove feeds pellets and the fans run like they should when it is starting up, but it does not light. Just fills the burn pot up.
 
Checked the exhaust duck was not clogged. Inspected the tubing didn't see any breakages. It doesn't give any error codes. This is what the manual says to check:
PrOBLEM

CAuSE: Auto-Start Igniter fails to ignite the fuel in the burn pot.

Stove does not start a re when the “ON” button is pushed

  • Turn the stove “OFF”. Clear the unburnt fuel from the burnpot and try again.

  • Check the pellet quality. Replace if moist, wet, or dirty.

  • Loss of draft pressure. Make sure that the viewing door is closed and sealed properly. If not, adjust door catch and/or replace door gaskets. Check that all outside connections are clear of any obstructions. Check the exhaust system; clean as needed.

  • Check that the auto-start igniter is not blocked with ash or soot. (The igniter is located behind the burnpot on the back wall of the rebox.)

  • Check that the pressure switch connection to the rebox is free of ash or clear of obstructions.

  • The auto-start igniter gets “red hot” during start-up. If you can not visibly see the igniter glowing during start-up, then the igniter may need to be replaced or there is a problem with the electrical control system.

    Checked all, Even did the factory test sequence to check that all parts work properly. The only thing that kept failing was the pressure switch.
 
If your igniter is getting hot and it’s feeding pellets but your not lighting then it sounds like a bad gasket somewhere or a clog in the exhaust/venting. Take your entire exhaust pathway apart, clean the blades on your combustion blower, run a brush through your pipe and check any gaskets with a dollar bill or lighter. Smoke coming back into the house wouldn’t be a bad pressure switch. 9 times out of ten, pressure switch codes are a clog.
 
You might want to try and bypass the P.O.F / low limit switch. Unplug stove, bypass switch, plug in, restart stove. The draft fan should not run. If the draft fan does not run then you may need a new P.O.F/low limit switch.
 
I tried just putting a wired in place of the pressure switch. The stove feeds pellets and the fans run like they should when it is starting up, but it does not light. Just fills the burn pot up.
well at least you can lite the pellets with a MAP gas torch or just a propane torch. winter almost over so maybe run it like that and in the spring you will have time to go over it