Harman PC45 won’t stay lit

[Jason.ant]

Hello,

have been searching through the forums looking to see if anyone else is having similar problems as I am, but figured I would post and see if anyone can lend a hand.

I’m up in Alaska so when I say we run the stove a good bit, it is not an understatement. The house also has a pellet boiler as our primary heat source with an attached 4 ton hopper for our pellet supply. We have had this particular stove and have had zero issues over the last two winters.

About 3 weeks ago, I started noticing the stove would not run overnight. The inside of the stove was also covered in black soot. After reading the manuals and other forums, the stove got a very in depth cleaning to include the removal of the rear panels and the plate for the feeder fines. The exhaust probe was also cleaned and the flue was removed and cleaned as well. After cleaning, the stove would run through it’s ignition and once the flame was visible, the blower would pulse 6-8 times until the flame was self sufficient. Roughly ten minutes later the flame would start to resemble a lazy campfire and eventually go out within an hour. Sometimes I would get 6 blinking dots, sometimes I wouldn’t.

At that point I choose to order a new combustion motor and fan blade and with the help of some parts from the lower 48, see if that was the problem. Install went just fine, gave it one more once over with the shop vac and reinstalled. Fired it up, normal start sequence with one 5 second blast of air to get the flame going and everything looked normal. Threw a five gallon bucket of pellets in and set to having a few beers thinking I had figured it out.

Next morning the stove was running wonderfully, had been for the last 16 hours, and then it went out and back was the black soot everywhere, most noticeably the glass.

So just finished cleaning it again and writing this post to see what you fellow pellet burners have for me.
Thanks

 

[Nitro-Fish]

Two years without issue; have you always burned pellets in it? I'm sure you are aware there is a pellet plate & a corn plate for this stove. You mention cleaning the stove but no mention of cleaning the flue, that would be a good place to start.

 

[Jason.ant]

The only Harman dealer Around has record of selling the stove in 2010. We moved in March of 18 and it’s always ran like a champ. It does still have the grain burn pot but has always ran fine with it in. The flue was cleaned out two weeks ago when everything was torn apart.
I’m debating on picking up a bag of pellets to see if I had a bad batch but my boiler in the garage has been running well.

 

[Don2222]

Did you check the auto damper which is that flapper on the air inlet pipe to make sure it is moving freely?
Also check the vacuum switch and check the vacuum hose to for any blockage?
Yo can bypass the vacuum switch by removing the 2 wires and connecting them together. Unplug the stove first and tape the wires to make sure they do not short out by touching the stove body.
If that checks ok then the circuit board may be suspect. Is the stove plugged into a good Tripp Lite surge protector or even better a line conditioner that actually regulates the voltage to keep it at 120 VAC?

 

[gutlo]

Have you cleaned put the dust under the burn pot? Have you poked out the burn pot holes?

 

[Jason.ant]

@Don2222, with the stove in test mode, the flapper moves freely and I would say it is half open. If I open it all the way by hand, the combustion motor shuts off. I am guessing this is a safety that deals with the vacuum??? I will check the vacuum switch but all the tubing has looked very much clear of blockages. I suppose I can attempt to splice the wires to bypass and see where that gets me. I am swinging by the one dealer in town in hopes they will rent out a draft meter to see if that’s the problem. At that point I think I will have to load up the stove and take it to them at $100 an hour.

@gutlo, I have cleaned out the “wind tunnel” as well as the burnpot so that all of the holes are free.

 

[Don2222]

If you open the damper all the way, the exhaust blower should not shut down. That maybe a clue to the problem.

 

[Jason.ant]

@Don2222

I was incorrect in my last statement. The auger stops feeding pellets which I would assume means the vacuum switch is sensing too much air. I’m still trying to get my hands on a draft meter to see where we are at with the draft.

 

[johneh]

Try bypassing the vac switch

 

[Nitro-Fish]

If you have a clear flue (what/how is the flue set-up for your particular application?), the stove should be able to handle all of the intake air without issue. When you say the auger stops, do you mean immediately? The auger will cycle under normal conditions. I'm guessing you are experiencing a "lazy flame" when the stove is burning? Have you tried the test mode to make sure the exhaust blower is ramping up and down properly? You didn't mention if the exhaust blower plate is the small one (#1-10-02677W for corn) or the large one (#1-10-08516S for pellets). You also say the burn pot is still the one for corn, the pellet burn pot can be had reasonable (especially aftermarket this time of year if you so choose). What kind of shape is the door gasket in, have you tried the dollar bill test? How about the door glass gasket? your issues soot, shut down etc. lead me to believe it's an air problem.

Also, when you replaced the exhaust blower did you use Harman OEM or aftermarket? Some of the aftermarket ones do not rotate in the correct direction, easy enough to change, but just another thing to check.