P38 weak fire

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Stimpack21

New Member
Mar 25, 2020
7
Enfield CT
Hello!

I just replaced the combustion motor, fan and ESP probe on my Harman P38. Can anyone help with the weak fire symptoms you see at this link?

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Thanks,
 
If the stove flame is low it could be normal if the stove thinks it's met the demand for heat. Have you run self test? Set it to stove temp, feed rate 4, and turn it up to 90 and see how it runs.
 
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Thank you! Here is what happens when I put the feed rate and blower at 2/3's (around 4 or 4.5). By the way, this is the old circuit board which just had 2 dials (no lights, no test buttons).

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It used to run with a very strong flame and didn't have this 'dying off' cycle. Thank you SO much for the help.
 
Are you the original owner of this stove and have cleaned it thoughly ? When you crank up the feed rate does the auger continuously feed or does it the flame die due to lack of pellets..?
 
I'll get answers to your auger question soon. But, I'm not the original owner but I've owned it for 7 years and it is located at my rental property. They HAVE used some cheap pellets in the past. The chimney, burn pot and fire box area had been cleaned very well. I also cleaned out the fines box which was 100 percent full! When I cleaned out the fines box, I made sure the nearest notch in the slide plate was filled with the vertical piece of metal. At least, I thought that was the correct assembly (that another piece of metal sticks into the slide plate to activate it).
 
With the feed rate 3/4 of the way up the auger turns on every 30 seconds. The flame still goes on off on off. Hope that helps, let me know what you think
 
When you say “cleaned the burnpot” were the holes in the burnpot opened right up with an Allen key or something similar sized? Cheap dirty pellets will clog them up and it won’t deliver the proper amount of air, resulting in a poor or lazy flame like in your video
 
Do you have a room probe? If so, make sure it is fully seated into the back of the stove. If it isn't seated, the stove gets confused as there is absolutely no reading, which will cause it to just idle. May not be the issue but a cheap, and easy thing to try. Had this happen on my P61a and it drove me nuts trying to figure it out.
 
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It looks like your combustion blower is fine - it's just not feeding correctly. Make sure everything is sealed. My P38 did this once and I discovered my ash pan door was not completely shut. If everything is sealed I would suspect something is not right with your ESP (even though it is new).
 
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Your insurance carrier must be very lenient. I would never allow any of my tenants to have a biomass stove, I own 4 rental properties. My insurance carrier would cancel me in a second if any of them had a unit installed.. Only conventional heat and AC allowed. Not that I would even if it was permitted. Renters tend to be very irresponsible when it comes to things like that. Bad enough taking care of washers and dryers and dealing with plugged up drains. One thing I've learned over the years and that is, if they don't own it, they don't exhibit a responsible attitude. Don't even have fireplaces in them.
 
So the stove was acting like this, you replaced the combustion blower, fan,and ESP, but the problem is still there ? I had the old 2 knob board, if I recall, when on turbo mode it just continually feeds ??
 
Bogieb, I don’t know of a room probe on this stove. It only has two dials (blower and feed rate), so I don’t think it is currently sensing the room temperature.

M159267, thank you – I also wondered if it wasn’t sealing as well as it should. I will look into this. Do you know how to test the gaskets besides looking at them?

SidecarFlip, I used to live in the property so I installed the pellet stove in there for myself in my 20’s. Only one insurance carrier would take on the fire risk. It turned out to be a relatively dumb idea to put a stove in there, but it has worked out so far and I can ask a higher rent to cover the insurance cost. Probably still a dumb idea…

Gfreek, a little history: a week ago, the stove was ONLY turning on the distribution blower and there was no combustion blower or pellet feed. I cleaned the whole stove (except burn pot holes) and cleaned the fines box and got the same results. So, I ordered/installed the new ESP (about $20) and the combustion blower still would not turn on. I plugged in the new combustion blower and it WOULD turn on, so I thought it was reasonable to install it. So, it now has a new ESP probe and new combustion blower (which turns on now). The new combustion blower also allowed the auger to start working again. But, the fire is going on and off on and off as you can see.
 
Door gasket test, " dollar bill test". Grab a dollar bill, open and close the door with the bill in between, pull on it, you should feel resistance all the way around. Both doors..
 
SidecarFlip, I used to live in the property so I installed the pellet stove in there for myself in my 20’s. Only one insurance carrier would take on the fire risk. It turned out to be a relatively dumb idea to put a stove in there, but it has worked out so far and I can ask a higher rent to cover the insurance cost. Probably still a dumb idea…
One of my rentals was also one of my previous homes as well. When I occupied it, it had a biomass stove, when we bought the farm and moved out, so did the unit and the vent hole was drywalled and the outside siding replaced, like it was never there. renters never exhibit much responsibility, human nature, so I won't allow them to have any excuse to 'roast 'one of my dwellings, besides my carrier won't allow it. They are all insured against loss and I require them to carry renters insurance. Been playing the landlord game a long time. I've seen it all and evicted a few too. You comment about 'cheap pellets' and obvious no maintenance just reinforces my premise about renters in general. Think I'd be taking the unit out entirely and calling it good as the unit will be a continuing source of problems because your renters won't take care of it anyway.

If I had it to do over, I wouldn't have any (rentals). Sure they increase my net worth and are an investment but I try to mitigate, as much as possible, ongoing issues and In my opinion, a biomass unit is ANY rental is an ongoing issue. So you repair it and all is good and next season it becomes an issue again. it's the rinse and repeat thing due to the renter mentality. Like I said, I'd eliminate it.

Kind of reminds me of the dishwasher story. My rentals all have dishwashers and all appliances included. I always include operating instructions with each but like biomass stoves, people never read the operating instructions. Renters used ordinary liquid dish soap in the dishwasher and it turned into a foaming machine. Ruined the kitchen floor too and of course they never said anything until after the fact of the stupid deed. Cost me 7 grand to have the floor and sub floor replaced. Need less to say, they are no longer there. Their security deposit didn't even come close even after I paid my deductible on the insurance.

I just don't play that game. One, I don't have the patience for stupidity and two, don't have the time. My attorney drew up my rental contract and the abide by it or they are gone. No shortage today of potential renters. problem is, it's hard to find responsible ones. Believe me, I'm very partiucular.