Harman PC45 issue

[msmith56]

Hello, I have had my Harman PC45 for several years now and have had a very good experience with it up until now. This past season it started to behave abnormally. I have the stove set on full auto and I have the external temperature wire. When the stove starts up it will run the auger, blowers, and igniter and then appear to stop momentarily and then turn everything back on again and then stop and start erratically. This erratic behavior continues after the stove ignites the pellets. The blower fan will speed up and slow down and the stove may somewhat operate for a while and then it seems to shutdown as normal.

So after googling and searching websites I completed the following steps.

I have cleaned the stove thoroughly cleaning everything that I can clean. I cleaned the interior, the exhaust fan, the stove pipe, and removed and cleaned the ESP. After cleaning the stove thoroughly I fired the stove back up and things appeared to be fine but after a few cycles the problem reappeared.

After the problem reappeared I replaced the ESP with a new one. I also removed the control board from the side of the stove and made sure that all connections and plugs on the control board were what to appeared to me to have been seated properly. I once again fired up the stove and the problem appeared to have been resolved but after 1 or 2 cycles the erratic behavior continued.

From my understanding the control board is one of the more expensive parts to replace but I want to rule it out before spending close to $300 for the replacement board. I'm hoping that someone on here can help me to troubleshoot the issue properly to rule out other inexpensive components that may be causing the issue and replace or troubleshoot those first before replacing the control board.

Any help will be greatly appreciated.

 

[Lake Girl]

Run in manual or auto? Have you tried switching from the mode you are currently running in? Have you tried changing knobs from normal settings? Apparently the potentiometers on the board do fail after a period. Try a search of the forum for potentiometers or pots to get a better idea of how the stoves react when they fail... External temp probes have been known to fail too. Changed out fuse for a new one?

There are repair services for the board: (broken link removed to http://www.kijiji.ca/v-other-services/guelph/pellet-stove-circuit-board-repair-harmon-invincible-t/1108635927) This one has been around for quite a while and seems to be reliable. If you do buy a new board, you may still want to send the old one off for repair so you have a back-up.

Keep us posted and welcome to the forum!

 

[msmith56]

Lake Girl, Thank you for the suggestion. This issue appears to be very similar to old volume controls on stereos. If you try to change the volume you might get the crackling or no volume at all. This could very well be my issue! I have cycled all 3 control knobs several times each and I just fired up the stove in auto mode room temp mode and so far it appears to be behaving normally. I'll know more as the day progresses but I'm hoping you hit the nail on the head with this one. My next course of action is the 100k potentiometer set on eBay in the event I continue to have problems. Thanks Again for the advice and I will update this post if the problem happens again.

 

[bogieb]

Your stove's behavior sounds close to how the stove should gracefully shut itself down if it is on a compatible UPS and the power fails (the blower will ramp up and down anyway).

If you have it on a UPS or power conditioner, is it getting past its prime, or did you just install it this winter (if either case, try running it straight from an outlet an see how it reacts)? On a the other hand, did you take it off of a UPS or power conditioner?

What about electrical outlet, is it on the same one you have been using? and, if so could it possibly gotten damaged? If it is a different one, have you checked polarity (don't' ask me how, I'm parroting stuff I have learned on this forum ).

Oh, and welcome to the forum!

 

[Lake Girl]

update this post if the problem happens again.

Let us know if the pots are the cure too!

 

[bogieb]

Lake Girl, Thank you for the suggestion. This issue appears to be very similar to old volume controls on stereos. If you try to change the volume you might get the crackling or no volume at all. This could very well be my issue! I have cycled all 3 control knobs several times each and I just fired up the stove in auto mode room temp mode and so far it appears to be behaving normally. I'll know more as the day progresses but I'm hoping you hit the nail on the head with this one. My next course of action is the 100k potentiometer set on eBay in the event I continue to have problems. Thanks Again for the advice and I will update this post if the problem happens again.

Glad she was able to help - if that is the permanent cure then that is a mighty cheap and easy fix compared to your initial thought!

 

[msmith56]

At this point I'm convinced that is where the problem is. The stove has run all night without any issues. From my understanding this is a common problem with these stoves but I am quite handy with a soldering iron so I went ahead and ordered 2 sets of pots off of the guy on eBay. I have my PC45 upstairs and a XXV downstairs. I asked him what his thoughts were and he feels that this is the issue. Cycling the knobs resolves the issue temporarily but eventually they will fail. But replacing the pots for $25 is a lot better then replacing that board.

Bogled, Thanks for the advice but I don't have the stove on a UPS. I could though see how that could be the issue as well. If and when it does act up again I will update this post.

Thanks to both of you for your help on this issue, I really appreciate it!