Noise in Harman P61a combustion motor

[P51mustang]

Hello gang,

I just this week started noticing that my combustion fan is beginning to sound inconsistent in terms of its volume and pitch as it operates. My stove was installed in April 2012 and given i operate the stove in manual mode pretty much from early October to early April, the stove and thus the motor has had lots of use.

I'm told by my dealer that usually this type of thing happens just before the motor dies completely. They also explained that the fan blade for the exhaust just behind the ash pan also must be removed in order to remove the combustion motor from the shaft. A colossal pain in the ass given it's very difficult to loosen the set nut holding the blade.

I'm wondering if anyone who has changed their own combustion motor can clarify this and if there's anything else to consider before I have the dealer replace the combustion motor. In other words, could it just be the bearing on the motor that spins around the shaft that needs replacing? If so , can I buy a replacement? Is there some lubrication issue I should consider? Just mostly curious and will probably have the dealer replace it anyway. But, any help or any suggestions are most appreciated. Thanks.

 

[gfreek]

Most likely bearings & they can be replaced. But I'd recommend buying a new motor and rebuild the old one. I installed new bearings in my Harman, they were an odd shaft diameter, not common..Yes the fan behind the ash pan, and probably an access plate has to be removed. It has a set screw to loosen, then remove the fan from the shaft. Either or both of these could be an issue but there are ways to deal with them..

 

[P51mustang]

Most likely bearings & they can be replaced. But I'd recommend buying a new motor and rebuild the old one. I installed new bearings in my Harman, they were an odd shaft diameter, not common..Yes the fan behind the ash pan, and probably an access plate has to be removed. It has a set screw to loosen, then remove the fan from the shaft. Either or both of these could be an issue but there are ways to deal with them..

Thanks for the reply....I ended up replacing the motor and fan blade. The dealer was amazed at how easy it was removing the fan blade given the set screw can be a groan to remove and they often have to cut the shaft completely off in order to replace the motor. $280 bucks later and my stove is quiet again.

I'm wondering if anyone can suggest some routine maintenance I can do to extend the life of the new replacement motor. Seems 4 and 1/2 years is not very long for this motor to last and so anything I can do to extend the life would be very helpful. Thanks....

 

[ABusWrench]

Hey P51, I too have a P61a, and I think I can detect a slight "noise" in my combustion fan on cold startup. Started this year. Once it warms up it goes away. Being it's third season with over 14 tons run thru it, and main heat source, I imagine it's starting to wear a bit. I agree with gfreek, as I too will buy a new motor/fan and just swap it out when needed. Then I'll rebuild the old one. Always nice to have a spare! Seeing as these are sealed bearings, there's not much you can do but keep it clean and hope for a long full life! IMO

 

[P51mustang]

Abus,

I would suspect your noise at cold start up is probably the result of corrosion beginning to occur within the motor or bearings somewhere and once the stove runs a bit it wears the corrosion out thus the noise ends.

Given it's nearly impossible to prevent all moisture from getting into a stove and its moving parts, it's inevitable. As you said in your post, since the bearings are sealed, there isn't much an owner can do in terms of maintenance to prevent bearing and ultimately motor failure.

I should add that I think my motor had been gradually getting louder as I noticed when I returned home from work last night and the repair had been completed just how quiet the stove was. It was really evident so I suspect it's been getting louder over some amount of time and it was only last week when it sounded like a freight train (okay, not that loud, but you know what I mean) that I knew something wasn't right.

When I paid my bill today, the owners sister who pretty much runs the show room and shop, mentioned that she owns a P61A as well and her first combustion motor lasted about 8 years before her first replacement. That replacement last about another 7 before she put her second replacement in. Makes me wonder why my first made it about half as long as hers. One thing I will make a habit of is cleaning the motor area every time I do my 2 week cleaning. Another ten minutes of effort may be worth it.

 

[Bioburner]

Have you gotten back there with a vacuum and did a proper eviction of dust bunnies? Heat kills these motors and if the motor gets extra warm it can turn the grease in the little bearing into a liquid and out it goes along with your $$$. Amazon has a vendor selling the motor for around $100. The fan is usually stuck on and has to be replaced too. If one puts a dab of antisieze on the shaft and set screw the next time will be a non issue. A electric motor shop can get that old motor back to useable shape..

 

[gfreek]

Mine lasted about 6 years then started to get noisy. I replaced it, and put new bearings in the old one as back up.. Really not much you can do as was mentioned the bearings are sealed ...

 

[P51mustang]

Have you gotten back there with a vacuum and did a proper eviction of dust bunnies? Heat kills these motors and if the motor gets extra warm it can turn the grease in the little bearing into a liquid and out it goes along with your $$$. Amazon has a vendor selling the motor for around $100. The fan is usually stuck on and has to be replaced too. If one puts a dab of antisieze on the shaft and set screw the next time will be a non issue. A electric motor shop can get that old motor back to useable shape..

Cleaning the dust out from and around the combustion motor is one thing I didn't do on a regular basis. Now I will do it every time I complete my two week extensive cleaning. I have to admit when I checked the motor and discovered it was in fact the source of the loud noise, there was significant dust built up around it. Even a couple pellets sitting on top of the grill surrounding the blades. I knew right away this was not good, but your point about heat and grease loss makes complete sense.

Your price of $100 bucks seems about right as my dealer charged me $128 for the motor, $16 for a new fan blade (fan inside the ash pot), and $120 bucks in labor. Lesson learned is: "Consistently clean in and around the combustion motor!"

Anyway, thanks for the replies and helpful insight everyone...

 

[Tonyray]

I have the same stove .. 4th yr now....
seems to make a little noise at times but when I move the knob up or down a smidgen, it goes away..

btw: don't think it hurts to do this but once every few months I put a drop of penetrating oil on the shaft set screw..
[hoping the blade will come off easier when the time comes]...
I have read though where having to saw the shaft off due to a stubborn blade is not un-common..

 

[Bioburner]

At least annually. I do a good cleaning at end of season. Pulling the room fan and cleaning the fins is one that lot of owners don't get to till complaining of no air flow. Us pet owners have to be way more attentive to that.
Your about due for new door gaskets. The graphite impregnated rope is very nice and seems to keep its form better than the old white stuff. At only around $10 is a easy project and will keep the stove running at peak efficiency.

 

[Tonyray]

At least annually. I do a good cleaning at end of season. Pulling the room fan and cleaning the fins is one that lot of owners don't get to till complaining of no air flow. Us pet owners have to be way more attentive to that.
Your about due for new door gaskets. The graphite impregnated rope ..

who carries the rope you described?

 

[Bioburner]

Home improvement stores and farm stores is where around here but sure online with the info on picture

 

[Tonyray]

Home improvement stores and farm stores is where around here but sure online with the info on picture
View attachment 193609

So how do you know when u need a new gasket?
mine doesn't look any different than when I bought the stove....

 

[Bioburner]

The dollar bill test or take a grill lighter with a long flame and run it around the door and see if the flame sucks in.
Take a bill and close door on it and latch and attempt to pull the bill out. If it slips easy then its time. Repeat all the way around the door.
Surprised you haven't heard of the test as you have been here awhile

 

[Tonyray]

The dollar bill test or take a grill lighter with a long flame and run it around the door and see if the flame sucks in.
Take a bill and close door on it and latch and attempt to pull the bill out. If it slips easy then its time. Repeat all the way around the door.
Surprised you haven't heard of the test as you have been here awhile

yes.. I know about the dollar bill test.... the top right corner of my stove never held a dollar bill tight since day one but I was never concerend about it since there was no discoleration at that spot.
since talking about stove doors, is there any adjustment that can be made to make it a tighter fit?
P61A,

 

[Bioburner]

Well it sure isn't on the hinge side. Someone had got some adjustment of the latch side. I can't remember from when I rebuilt two Harmans and one had a broke handle. For the $10 and half hour at most time the replacement of the gasket is a win in my mind anyway. My stove consumption went down although not muck but the flame improved when I did mine.

 

[Tonyray]

Well it sure isn't on the hinge side. Someone had got some adjustment of the latch side. I can't remember from when I rebuilt two Harmans and one had a broke handle. For the $10 and half hour at most time the replacement of the gasket is a win in my mind anyway. My stove consumption went down although not muck but the flame improved when I did mine.

Yeah...
probably will change it this spring as I will going into 5th burning season with it.

 

[P51mustang]

Curious as to how much cement should be placed on the gasket material. A small bead all around in the middle of the gasket for instance? Also, I assume when removing the old gasket I'll need to scrape away as much as possible in order to make the tightest seal possible with the new gasket?

Finally, is the 3/8" size correct for the P61A? Thanks

 

[P51mustang]

I have the same stove .. 4th yr now....
seems to make a little noise at times but when I move the knob up or down a smidgen, it goes away..

btw: don't think it hurts to do this but once every few months I put a drop of penetrating oil on the shaft set screw..
[hoping the blade will come off easier when the time comes]...
I have read though where having to saw the shaft off due to a stubborn blade is not un-common..

My dealer told me my blade was the easiest he's ever removed and he typically does saw the shaft off to remove the blade....I always clean the blade and exhaust area in general when I do my two week cleaning. However, I've never put any anti-seize or penetrating oil on the set nut.

 

[alternativeheat]

As long as you are going in to clean around the combustion motor, you might as well have a look at the distribution fan as well ( room fan). mine likes to catch the underfur of our cats, the finest of the fine part of their fur. I can only imagine that a fan blade will bog out the motor a little with that stuff on there, reducing motor life.

 

[alternativeheat]

Yeah...
probably will change it this spring as I will going into 5th burning season with it.

Tony, I changed my ash door gasket the first week of owning our P61 ( about the same age as yours). I checked around my doors with a grill lighter flame and the whole lower right side of the door sucked the flame in. So rather than deal with the dealer and all that I just went to the hardware store and bought the next gasket , one thickness up in size. The door felt loose to me before ( which is what prompted me to check for leaks to begin with) and it closed nice and snug after and still does. And the flame from the lighter no longer got sucked in.

That whole lighter flame trick I used for decades on my coal stove , long before ever owning a pellet stove. Actually year s ago I used a candle flame.

 

[Tonyray]

Tony, I changed my ash door gasket the first week of owning our P61 ( about the same age as yours). I checked around my doors with a grill lighter flame and the whole lower right side of the door sucked the flame in. So rather than deal with the dealer and all that I just went to the hardware store and bought the next gasket , one thickness up in size. The door felt loose to me before ( which is what prompted me to check for leaks to begin with) and it closed nice and snug after and still does. And the flame from the lighter no longer got sucked in.

That whole lighter flame trick I used for decades on my coal stove , long before ever owning a pellet stove. Actually year s ago I used a candle flame.

do you remember the thickness size you bought and what adhesive you used?
and, did u remove the door for the install?

 

[alternativeheat]

do you remember the thickness size you bought and what adhesive you used?
and, did u remove the door for the install?

I used red RTV to attach it. I really don't recall the size though. I went to the store with the old gasket and just bought the next one up. But remember this was the ash pan door, not the main door. The main door still has original gasket material in it. I removed the door , yes.

 

[Tonyray]

I used red RTV to attach it. I really don't recall the size though. I went to the store with the old gasket and just bought the next one up. But remember this was the ash pan door, not the main door. The main door still has original gasket material in it. I removed the door , yes.

oh..ok..
thought it was the Main door....

 

[Tonyray]

I used red RTV to attach it. I really don't recall the size though. I went to the store with the old gasket and just bought the next one up. But remember this was the ash pan door, not the main door. The main door still has original gasket material in it. I removed the door , yes.

dumb question but,
did u check while the stove was running I assume?