# Harman P61 problem



## rsoucy (Oct 15, 2013)

I have a P61 that I have used extensively for about 6 years with no problems. I do my own maintenance, only cleaning so far. I cleaned the stove this fall for the winter season. It started right up and worked fine for about 3 days. I turned the thermostat down a week ago since we have had some nice weather here on Cape Cod. I filled the hopper and dialed up the thermostat yesterday and nada. I am getting nothing - no auger, no combustion blower, nothing. I am getting power to the unit since all leds (combustion, circulation and feed, power and status) but again, nothing. I emptied the hopper and cleaned out the auger tube as best I could without disassembling and the lack of response is the same. I have tried it in test, room and stove mode and the response is the same - nothing. The leds light up but there is no system response. I have listened closely for any sound of activation while tuning it on and off in the event the auger or fan is bound, but do not hear anything.

Any ideas on where to start debug? Any suggestions would be greatly appreciated as I am looking at a $200 up front charge for the first hour of service if I need to resort to calling someone in.

BTW, I am really happy with the stove. 6 years of hard use as a primary heat source and I have not had a single problem with the stove (knock on wood). We own two other P61s in other homes we own and they likewise have worked flawlessly for years with no maintenance other than cleaning.

Thanks in advance for any suggestions.

Rick


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## Delta-T (Oct 15, 2013)

give the combustion blower a spin by hand (behind ash pan). it might be stuck. if it doesn't go, nothing else will go.


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## Delta-T (Oct 15, 2013)

make sure to unplug it before you stick your hand in there too


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## rsoucy (Oct 15, 2013)

Thanks for the response, and yes, I did remember to unplug prior to sticking my hand in. The combustion fan is and was free - but still not running.

I have done some further cleaning, which it did not really need. I cleaned and inspected the esp probe and probe wiring. I checked the 3A fuse on the board and it is fine. Still the same symptoms - all leds light (power, status, combustion, distribution and feed), and additionally the status light is lit constantly, yet neither the combustion blower nor the auger run in any mode (stove, room or test). When it is in test mode I can get the distribution blower to run, but neither the combustion blower nor auger run in test mode.

Is it true that the combustion motor must begin running before the auger will engage? If so I suspect there is a clue in the fact that the combustion blower led lights (indicating power is getting to the combustion blower) yet the blower does not run. It would appear to be a problem with the combustion blower and since it is not fused in line would indicate the blower is probably dead? The lack of combustion motor would explain the auger not running. Does this make sense?

Rick


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## rayttt (Oct 15, 2013)

Yeah.. If no combustion going..no vacuum..no auger feed.
You can test the blower by disconnecting it from the wires going to the pcb and jump right to the line cord coming in.


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## Bob Sorjanen (Oct 15, 2013)

maybe a dumb suggestion but have you tried without  the thermostat hooked up?


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## Lousyweather (Oct 15, 2013)

nah.....disconnect the leads to the combustion fan, make a pigtail, hook the fan up directly to line voltage and see if it runs....if it doesn't run, its the fan, if it does, its something else we can pursue....


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## rsoucy (Oct 15, 2013)

Bob Sorjanen said:


> maybe a dumb suggestion but have you tried without  the thermostat hooked up?


 
It is a good suggestion but that is basically what the "stove" mode and "test" mode do on the P61. "stove" mode uses an internal sensor different than the external room temp sensor. Something could be broken in that area to cause them both to go out, but the "test" mode basically just forces the stove to run (I believe) independent of the temp sensors. There could be some condition that causes an override but...

I am getting ready to check the fan by hardwiring it, and am also going to check to insure I am getting power at the terminal on the fan with a DMM which should eliminate any and all potential sensor issues.

I suspect the fan.

Thanks again for responding. I just fortunately stumbled on this site. It seems to have a very high signal to noise ratio - lots of knowledge and helpful people.

Rick


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## imacman (Oct 15, 2013)

rsoucy said:


> ....I am getting ready to check the fan by hardwiring it....


That was my next suggestion.  Do yourself a favor....make a power test cord out of an old lamp cord.  Comes in very handy for testing blower & auger motors.  

As always, be sure to INSULATE the leads.


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## rsoucy (Oct 15, 2013)

The saga continues. It would appear as expected that the combustion motor is dead. I hot wired directly to the terminals and nothing. What is interesting is that while checking the power to the motor I think I have discovered that the power to the motor is never interrupted. Regardless if I have the stove set to "room" mode with the thermostat set to 50 degrees (it is 72 in the room at the moment), or in "stove" mode, there is always 120V AC power to the motor leads coming off the board. I would assume this is not normal and there should only be power to the combustion motor when there is a call, which certainly is not the case with the thermostat set to 50 degrees in a 72 degree room? It could also be that the thermocouple room sensor is messed up, but I believe that in "stove" mode with the thermostat turned down all the way it should be off also.

It appears that the board has power switches rather than relays. Does anyone know if these are easily replaceable or am I looking at doing pcb rework to attempt this? Could I be looking at a new board in addition to a new motor?

Any thoughts?

Again, thanks in advance for any advice.

Rick


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## Lousyweather (Oct 15, 2013)

you'd be partially wrong.....while the stove is running, there is ALWAYS power to the combustion blower.....not always to the distribution blower or the feeder. Dis blower is controlled by the ESP and the potentiometer setting (L thru H). The only time the comb blower isn't powered is when the stove is in shutdown and cool....in its "wait" state, checking the room temp, waiting for it to get low enough to re-ignite. But under operating conditions the combustion blower will always run if there is a fire, its lighting, or its in TEST mode. If you hardwired the fan and it didn't start, its failed. get a new one.


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## Lousyweather (Oct 15, 2013)

oh, no, replace the fan first......you likely don't need a new board.


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## rsoucy (Oct 15, 2013)

Lousyweather said:


> oh, no, replace the fan first......you likely don't need a new board.


 
Thanks Lousyweather, I do intend to replace the motor. I am getting ready to order one tonight. I am currently wrestling with the fan blade attempting to get the collar set screw loosened.

I still have a question that I would appreciate clarified. I guess I should note that this is actually a p61a with auto ignition. When I power the stove up initially, no fire, stone cold, and I have it in "room temp" mode with the thermostat set to 50 degrees and the room temp is 72 degrees why should I expect the combustion motor to run? There is no call for heat so I would expect the stove would sit in idle mode until the temp drops below 50 degrees in the room, or I turn the thermostat above the room temp to create a call for heat. At that time I would expect the combustion blower to start up, create a vacuum, engage the auger motor and the igniter and voila, heat. I have not paid much attention but again, unless there is an initial call for heat when I plug it in I would expect it to just sit there.

Wrong?


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## P38X2 (Oct 16, 2013)

I believe you must have the toggle in the manual ignite setting if you're experiencing that scenario. Switch it to auto and the combustion motor should turn off. The combustion motor is running in anticipation of you lighting it. Don't tease it like that


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## Harman Lover 007 (Oct 16, 2013)

Sounds like you are on the right track....but to be "sure" did you make a pigtail and power the motor from an outlet or did you get the power from the stove? Gonna get cold here next week so you'll want to get that motor ASAP.


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## rsoucy (Oct 16, 2013)

P38X2 said:


> I believe you must have the toggle in the manual ignite setting if you're experiencing that scenario. Switch it to auto and the combustion motor should turn off. The combustion motor is running in anticipation of you lighting it. Don't tease it like that



Well, that is why I believe I have a problem. It behaves the same whether I have it in manual ignite mode or auto. As a result of your suggestion I am going to re-check it today, but I did conciously toggle and try it both ways. I love my P61 and would never tease it 

BTW, I am going to just istall the new motor and ignore this other potential problem and hope the new motor fixes everything, but I suspect the new combustion motor is going to run continuously and I am going to be looking at the next problem.


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## rsoucy (Oct 16, 2013)

Harman Lover 007 said:


> Sounds like you are on the right track....but to be "sure" did you make a pigtail and power the motor from an outlet or did you get the power from the stove? Gonna get cold here next week so you'll want to get that motor ASAP.


I made a pigtail power chord and connected directly to the motor. I am absolutely certain the motor is dead.

I was going to order the motor last night online, but figured I would wait till this morning to talk to a live person and insure prompt shipping and expedited delivery. The OEM motor seems to be in stock in a couple different places so I would hope to have it late this week, or early next week at the latest. It shouldn't take more than a couple hours to get it put back together and running. 

I will keep my fingers crossed that the control board is functioning properly and that the symptoms I am seeing are some abberation due to my deficient debug skills.

Thanks for your input.


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## rayttt (Oct 16, 2013)

How old is your P61? 
Would it be covered by warranty?


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## rsoucy (Oct 16, 2013)

rayttt said:


> How old is your P61?
> Would it be covered by warranty?


 
It is six years old and out of warranty so it looks like I am footing the bill. At 6 years of heavy use I cannot complain. It has been an extremelyl reliable workhorse, so to replace a $150 motor is not a big deal. The control board will hurt though if it comes to that.


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## rayttt (Oct 16, 2013)

Just FYI you can get a replacement cheaper than $150 in http://www.grainger.com/Grainger/wwg/start.shtml


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## Lousyweather (Oct 16, 2013)

rayttt said:


> Just FYI you can get a replacement cheaper than $150 in http://www.grainger.com/Grainger/wwg/start.shtml


just don't destroy the interior fan in trying to get it off.....or you'll need one of those as well, and you wont find that at Graingers.......they can get brittle, and fins can break off. We give it a shot when replacing them, but VERY OFTEN, its hard to get them off, there's a trick or two to try, but maybe half the time we end up cutting the shaft and replacing both.....time is money, and it generally doesn't pay to mess with something for a long time when the tech has other stops to make.....


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## rsoucy (Oct 16, 2013)

Lousyweather said:


> just don't destroy the interior fan in trying to get it off.....or you'll need one of those as well, and you wont find that at Graingers.......they can get brittle, and fins can break off. We give it a shot when replacing them, but VERY OFTEN, its hard to get them off, there's a trick or two to try, but maybe half the time we end up cutting the shaft and replacing both.....time is money, and it generally doesn't pay to mess with something for a long time when the tech has other stops to make.....


 
Yeah, I have already run into that problem and am working on it. I put PB Blaster on it last night and again this morning. I am going to give it go shortly and if it is still stuck I am going to clean up the flammables and try some heat on that hub with an extinguisher nearby of course. I may just replace the fan. I believe I saw one for $12 somewhere. It would seem that insuring the fan is well balanced could be important to bearing and overall fan life?

If I cannot get the set screw loosened and have to resort to cutting the shaft what is the best tool to go after it with? Is that shaft hardened? I can't visualize getting anything in there but a reciprocating saw or by hand a hacksaw with no frame (not sure what they are called - looks like a keyhole saw handle with a hacksaw blade). Will this do it or do you have better ideas?

Thanks again for following along here. I am learning a bunch about my stove that is going to serve me well down the road as it gets older.

Rick


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## Lousyweather (Oct 16, 2013)

rsoucy said:


> Yeah, I have already run into that problem and am working on it. I put PB Blaster on it last night and again this morning. I am going to give it go shortly and if it is still stuck I am going to clean up the flammables and try some heat on that hub with an extinguisher nearby of course. I may just replace the fan. I believe I saw one for $12 somewhere. It would seem that insuring the fan is well balanced could be important to bearing and overall fan life?
> 
> If I cannot get the set screw loosened and have to resort to cutting the shaft what is the best tool to go after it with? Is that shaft hardened? I can't visualize getting anything in there but a reciprocating saw or by hand a hacksaw with no frame (not sure what they are called - looks like a keyhole saw handle with a hacksaw blade). Will this do it or do you have better ideas?
> 
> ...


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## P38X2 (Oct 16, 2013)

Is there a high temp anti sieze that could be used on that set screw for preventative measures?


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## Bioburner (Oct 16, 2013)

Catapillar has a very good antiseize. I don't know how small of container you can get it in. Loctite makes a very good product as well. I have a pint can with a brush. Great to have for hinge pins and bolts. A must have for spark plugs and glow plugs etc.


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## P38X2 (Oct 16, 2013)

Thanks, Bioburner. The copper Permatex is rated up to 1800F. That's an easy find. Anyone know if the set screw is the issue, or is it the actual fan seizing on the shaft?


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## imacman (Oct 16, 2013)

Are you trying with an allen wrench?  Some of the set screws on these have Torx set screws.


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## rsoucy (Oct 16, 2013)

imacman said:


> Are you trying with an allen wrench?  Some of the set screws on these have Torx set screws.


 
This had an allen on it. I was able to bet the set screw loosened and have the fan off and the motor out. I am going tomorrow to pick up a motor so should have it installed tomorrow evening sometime.

The PB Blaster seemed to work it free. I applied it to the top of the collar, and also shot it under pressure into the crack created by the flat spot on the shaft. It was locked solid yesterday, and did not take much to get it loosened today. The PB seemed to do its job.

The shaft was stuck but I had the fan unbolted so a sharp tap on the end of the shaft poking through the collar of the fan got it freed and it then came right out.

As I said earlier, I honestly believe I have a problem with the control board. It does not seem right that there is power to the combustion motor at all times independent of the mode and thermostat setting when the stove is cold. I am going to install the motor and get it fired up and observe the behavior. Could be I am missing something in my diagnosis so we'll see what happens.

So far all is well.


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## Lousyweather (Oct 17, 2013)

imacman said:


> Are you trying with an allen wrench?  Some of the set screws on these have Torx set screws.


many of the distribution fans have torx screws, but all the combustion fan impellers for the Harman that I've seen have been Allen


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## Don2222 (Oct 17, 2013)

I use a wire wheel on my drill driver to knock off the corrosion before applying the PB Blaster to the combustion set screw. That helps alot too.
See video and pics
https://www.hearth.com/talk/threads...wer-what-is-the-best-way.109353/#post-1440192

I know Harman has had some bug fixes to their control panel but they must be a well kept secret! Are their and Dealer service bulletins on control panel updates.
I am testing a P61a control board that does not keep the room to the temperature set on the dial within 1 degree! Not by a longshot? It is an older panel, Any list of bug fixes over the years?


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## rsoucy (Oct 17, 2013)

Success! The combustion fan is back in and the stove is running fine. My fears around a bad board at least at this time seem to be unfounded.

I suspect this is pretty basic stuff for most of you, but I wanted to thank the experts here that provided advice and support. I learned a boatload about my stoves (I have 3 P61as with hopper extension, nickel trim and lighthouse tile - somewhere in the $10K ranges invested in Harman) and feel a lot more confident about being able to maintain them and do basic repairs down the road. This is a great website with some very knowledgeable and helpful participants. I notice some contributors are professionals in the business and it is great that you are willing to take the time to share your knowledge and experience with a do-it-yourselfer.

Thanks again to all that contributed.

Rick


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## P38X2 (Oct 17, 2013)

Glad you're back up and running. This IS a great site.
*THREE* P61's!?!? Holy fricken BTU's! You heatin the whole neighborhood?


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## Bioburner (Oct 17, 2013)

What were the final damages for the motor?


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## Lousyweather (Oct 18, 2013)

rsoucy said:


> Success! The combustion fan is back in and the stove is running fine. My fears around a bad board at least at this time seem to be unfounded.
> 
> I suspect this is pretty basic stuff for most of you, but I wanted to thank the experts here that provided advice and support. I learned a boatload about my stoves (I have 3 P61as with hopper extension, nickel trim and lighthouse tile - somewhere in the $10K ranges invested in Harman) and feel a lot more confident about being able to maintain them and do basic repairs down the road. This is a great website with some very knowledgeable and helpful participants. I notice some contributors are professionals in the business and it is great that you are willing to take the time to share your knowledge and experience with a do-it-yourselfer.
> 
> ...



glad to hear you solved the problem! grats! (see post 12)


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## rsoucy (Oct 18, 2013)

P38X2 said:


> Glad you're back up and running. This IS a great site.
> *THREE* P61's!?!? Holy fricken BTU's! You heatin the whole neighborhood?


 
We have one installed in a 3000 sq ft home, a second installed in a 1700 sq ft home, and a third in a 1200 sq ft cottage. The first and third are primary heat sources and run constantly during the season. We have had all three of them for about 6 years and they have been extremely reliable workhorses.


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## lessoil (Oct 18, 2013)

rsoucy said:


> Thanks Lousyweather, I do intend to replace the motor. I am getting ready to order one tonight. I am currently wrestling with the fan blade attempting to get the collar set screw loosened.
> 
> I still have a question that I would appreciate clarified. I guess I should note that this is actually a p61a with auto ignition. When I power the stove up initially, no fire, stone cold, and I have it in "room temp" mode with the thermostat set to 50 degrees and the room temp is 72 degrees why should I expect the combustion motor to run? There is no call for heat so I would expect the stove would sit in idle mode until the temp drops below 50 degrees in the room, or I turn the thermostat above the room temp to create a call for heat. At that time I would expect the combustion blower to start up, create a vacuum, engage the auger motor and the igniter and voila, heat. I have not paid much attention but again, unless there is an initial call for heat when I plug it in I would expect it to just sit there.
> 
> Wrong?



Not sure if this is the same situation as above.
If I have our P61 set to Auto,Room Temp and temp at min when I plug it in, the combustion fan runs for a few seconds then shuts down.
Is that what you meant when you said "When I power the stove up initially" ?
Good luck with the motor!
This is our 6th year with the P61. Love it!!


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## rsoucy (Oct 18, 2013)

Bioburner said:


> What were the final damages for the motor?


 
I wanted to get it done quickly, and decided to go with a Harman OEM part so paid a bit more than I should have. $148 was the final tally. I found some cheaper online and some after market that were cheaper, but with expedited shipping it was actually cheaper to go the local dealer route.


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## rsoucy (Oct 18, 2013)

lessoil said:


> Not sure if this is the same situation as above.
> If I have our P61 set to Auto,Room Temp and temp at min when I plug it in, the combustion fan runs for a few seconds then shuts down.
> Is that what you meant when you said "When I power the stove up initially" ?
> Good luck with the motor!
> This is our 6th year with the P61. Love it!!


 
Mine does as you have just described. When powering it up (basically plugging it in after what Harman calls a "reset") my combustion fan comes on for a couple seconds then shuts down till I call for heat. I cannot explain what I was seeing during debug with the meter other than I screwed something up - I must have had the ignition switch on manual or ??? What I observed then was that the power to the fan output from the board was "on" at 120V all the time rather than shutting down after a few seconds. Again, must have been a bozo on my part because it obviously is behaving correctly with the new fan installed.


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