Symptoms: A month ago, shut down for the overnight. Following morning stove shut down but the fans were still running. Unplugged and plugged back in and all was OK. Yesterday, shut down for the first time in a week for full cleaning. Came home from work and all was off but the burn pot was full to overflowing of unburned pellets. Checked hopper half expecting to find it emptied, but no, it was half full. Not many unburned in ash pan. Unplugged and did complete cleaning. Removed and cleaned ESP. Cleaned all venting. Checked fines box-not much in there. Plugged in and with the dial set to "off", it did its quick and normal fan start and stop but then the status light light as well as the Combustion, Feed and Dist lights lit- all blowers went on high and auger started feeding pellets. Dial is at OFF position. Unplugged and plugged in-same thing. Opened door and auger stopped-Closed door and auger started--Vac switch seems OK Bad/dirty pot maybe? Unplugged and tried turning Blower/off dial back and forth 15-20 times. Same issue. Turned all dial 15-20 times. Same Issue Turned blower/off dial again about 50 more times and all worked as it should I believe it is time to have a control board on hand. Probably time for an ESP on hand as well. Been watching it closely to make sure that everything is functioning as it should.
I don't know jack about your stove but it certainly sounds like something flakey is going on with the board. Did you double check all of the connections to the board and switches and stuff and make sure nothing is corroded or loose?
Not gonna be much help for ya G, But wish ya luck and hope all gets sorted quick for ya. All I can offer is start with the simple less expensive stuff and keep the fingers crossed it fixes it. I'd start with the ESP and maybe try changing the pots nexts. If ya need some soldering tips ask away!
I'm with Jay on this one. Keep it cheap. The ESP is what senses temp, so it may be the screwy link? The Pots will be cheap as well. The board ?? Not so much? Maybe shoot Eric a PM?
In my experience, I changed the ESP probe and it did not fix the problem, still waiting until my friend has the money for a new circuit board. I believe a new board will fix the problem.
Had the same idea on PM'ing Eric and did that this morning. Yesterday was straight out, barely had time to start this post.
Today, I will be checking connections, but I am really leaning toward the board. If the issue involved only the fans staying on after shutdown, I might think ESP, but to find the fans off and a burnpot overflowing with pellets makes me think logic error somewhere. I would think that this means the auger had to have stopped completely after shutdown and then restarted for some reason. If the auger never shut down and also didnt stop stopped bumping (part of the shutdown process on a Harman) then the fire would never have gone out. The stove is 4 plus years old and although it has been on a surge protector from day 1, my rural area gets so many power blips that I would not be surprised with a bad board. As far as replacing the pot, I wouldn't want to try that when the stove is currently functioning properly. Murphy could very well get involved there and leave me with a non functioning stove. Waiting on pricing for an ESP and Board. Made a few quick calls to local dealers yesterday but could not get hold of anyone. Hopefully Eric will touch base. This may very well have been a dirty pot and be OK. Right now, everything is working ans all functions are responding to several test changes I have made to see appropriate changes in stove function. I wont be replacing anything unless I see any more issues, but I want to be prepared.
Has been working properly since my MacGiver version of cleaning the pot. That is why I want to leave well enough alone for now. The part that is stumping me is the auger feeding pellets after shutdown, but I guess a flaky pot could do that as well.
No status blinking lights. Status light is functioning normally. Off when the blowers and auger are off and during malfunction period, status light would come on steady with the motors running in OFF position. I did watch the status light during malfunction. Dial OFF**plug in stove**Status light comes on for a quick second as do the blowers and then goes out along with the blowers turning off (very normal after plug in)**then status light comes on as do all the motors but dial was at OFF.
UPDATE Well after 4 days, all is still running normal. Took advantage of the warmer temps today and did a shutdown. All went normal right down to combustion fan shutting down as it should. Did a quick upper firebox clean (might as well, its off) and restarted. All normal. Maybe it was the dirty potentiometer. For now, leaving well enough alone
That's good. Since you have some leway now maybe you should get a spare circuit board? It does take time to get the board. If you have a spare and it breaks down on a snowy cold weekend, then you will be all set! I have a spare Harman and a spare circuit board. This way I can fire up the spare machine so I will be warm when I change the board in main machine. LOL
Already checking into getting one and how long it would normally take, kind of tough time to spend money on something I dont need right now though.
