Harman p68 shut off issue

[green wood]

hello all...ive posted before as we had a quadrafire that gave us fits for years. We got castle serenty heating the 1st floor doing a fine job other than not being able to keep the house warm as we like it alone. We bought a p68 new many years ago and its been a really good stove until recently.

Will start up...burns for roughly 15 to 30 minutes then stops feeding and shuts off. I cleaned it, ive checked the rear fresh airway, cleaned the fines box an MADE sure it was closed and tight correctly. Cleaned the esp probe through the front of the stove btw, i did not pull it out.......

Also pulled my exhaust T cap off , amazingly wasnt full of ash at all....very little.

Tried running it in stove temp as well vs room temp. I do not run this stove all winter...just when it gets really cold as my basement does not have a heat source. Running one downstairs and one up stairs works well for us. Any other suggestions would be helpful cannot get the house much past 60 degrees in these low temps with just the serenity. Thank you.

 

[Whitenuckler]

hello all...ive posted before as we had a quadrafire that gave us fits for years. We got castle serenty heating the 1st floor doing a fine job other than not being able to keep the house warm as we like it alone. We bought a p68 new many years ago and its been a really good stove until recently.

Will start up...burns for roughly 15 to 30 minutes then stops feeding and shuts off. I cleaned it, ive checked the rear fresh airway, cleaned the fines box an MADE sure it was closed and tight correctly. Cleaned the esp probe through the front of the stove btw, i did not pull it out.......

Also pulled my exhaust T cap off , amazingly wasnt full of ash at all....very little.

Tried running it in stove temp as well vs room temp. I do not run this stove all winter...just when it gets really cold as my basement does not have a heat source. Running one downstairs and one up stairs works well for us. Any other suggestions would be helpful cannot get the house much past 60 degrees in these low temps with just the serenity. Thank you.

Any fault code flashes? Were you in stove mode at the time?

 

[green wood]

Any fault code flashes? Were you in stove mode at the time?

Yes 6 flashes. and when it started i was in room temp. Thought maybe i had a probe issue so i went to stove temp to try it...and it does the same thing

 

[Tonyray]

had 6 flashes on my harman p61a last week.. shut stove off/un-plugged and when turned back on it cleared..
never knew what happened.

 

[Whitenuckler]

Yes 6 flashes. and when it started i was in room temp. Thought maybe i had a probe issue so i went to stove temp to try it...and it does the same thing

A 6-flash error on a Harman pellet stove indicates incomplete combustion or low exhaust temperatures over 25 minutes, usually caused by too much air, poor-quality pellets, or a dirty unit. It signifies the fire is dying or failing to start properly, often due to improper sealing after maintenance.

How does the flame look? Did you have OAK? Outside air? I'd pull the ESP probe out for cleaning, inspection and measurement.

Harman ESP (Exhaust Sensing Probe) probes typically measure between
1,000 and 1,100 ohms (1k-1.1k

Ωcap omega
) when cold, specifically for the red-wire version. Other non-red ESP probes may read between 550,000 and 650,000 ohms, though the red-wire (Part# 3-20-00844) is the most common for modern Harman stoves.


Key Details for Testing:

• Resistance Behavior: As the probe heats up (when the stove is operating), the ohm reading should decrease.
• Red Wire (3-20-00844/385615):
  
  
  
  ≈is approximately equal to
  1050 ohms when cold.
• Black Wire (3-20-00744/3-20-11744): Typically used for older models or specific replacements, check for similar resistance behavior (lowering when hot).
• Fault Readings: If the probe reads zero (short) or infinite (open) resistance, it is faulty.

3-Blink Alarm: A 3-blink code usually indicates an issue with the ESP circuit.

Note: Always ensure the stove is unplugged and the probe is clean (using a Scotch-Brite pad) before testing with a multimeter.

 

[Whitenuckler]

hello all...ive posted before as we had a quadrafire that gave us fits for years. We got castle serenty heating the 1st floor doing a fine job other than not being able to keep the house warm as we like it alone. We bought a p68 new many years ago and its been a really good stove until recently.

Will start up...burns for roughly 15 to 30 minutes then stops feeding and shuts off. I cleaned it, ive checked the rear fresh airway, cleaned the fines box an MADE sure it was closed and tight correctly. Cleaned the esp probe through the front of the stove btw, i did not pull it out.......

Also pulled my exhaust T cap off , amazingly wasnt full of ash at all....very little.

Tried running it in stove temp as well vs room temp. I do not run this stove all winter...just when it gets really cold as my basement does not have a heat source. Running one downstairs and one up stairs works well for us. Any other suggestions would be helpful cannot get the house much past 60 degrees in these low temps with just the serenity. Thank you.

For sure check the connector on the board for the ESP. Good time to vacuum the fines compartment when the card is out.

 

[green wood]

had 6 flashes on my harman p61a last week.. shut stove off/un-plugged and when turned back on it cleared..
never knew what happened.

yes i tried that......didnt work sadly

 

[green wood]

For sure check the connector on the board for the ESP. Good time to vacuum the fines compartment when the card is out.

ok..i cleaned the esp via the ash box entry. ill try removing it from the actual stove and recleaning. I did clean out the fines box...i did not vacuum it tho. just cleaned it out with my fingers. some came out but wasnt packed as that is part my normal cleaning process.

the ohms thing is over my head, im not much of a mechanic. Ill probably end up trying a new esp if after cleaning it doesnt fix it.

Question.....could my exhaust pipe going out side be plugged but yet the t clean out be clean? because i checked that and it was pretty clean...not much ash at all. this is a basement install. the exhaust goes up the wall and through it, dumping out under our deck at ground level.
I cleaned it out two years ago as its a major pain to do, fitting under the deck. I thought about hooking up my dewalt leaf blower and reverse cleaning it back into the stove like ive seen online just incase the venting does have a restriction. I just assumed it didnt because of the lack of ash in the clean out.

BTW. no oak...stoves been installed this way for a decade atleast. Flame looks excellent andnormal when it does fire.

 

[Whitenuckler]

Ill probably end up trying a new esp if after cleaning it doesnt fix it.

The Stove will give a fault code if it thinks the ESP is totally broken.

I would think that if your exhaust piping were plugged the flame would not be that good. You probably would have seen something in the tunnel where the probe is. If you want to try the "leaf blower trick" that might help.

I don't think the ESP probes are too expensive, and it wouldn't hurt to have a spare anyway.

It's possible the control board is bad, but if you have had it on surge protection since day one, that would have reduced that possibility.

If the stoves came with the computer interface we could troubleshoot better. If your dealer has one that's an option.

 

[green wood]

The Stove will give a fault code if it thinks the ESP is totally broken.

I would think that if your exhaust piping were plugged the flame would not be that good. You probably would have seen something in the tunnel where the probe is. If you want to try the "leaf blower trick" that might help.

I don't think the ESP probes are too expensive, and it wouldn't hurt to have a spare anyway.

It's possible the control board is bad, but if you have had it on surge protection since day one, that would have reduced that possibility.

If the stoves came with the computer interface we could troubleshoot better. If your dealer has one that's an option.

yes i will look for a esp probe. it has been on a surge since new. We only have one game in town for harman and he knows it if you know what i mean. my friend had them come out and install an auger in her stove the bill was 1,100 dollars. I cant afford something like that so here i am thanks again.

 

[Washed-Up]

Also check that the esp is plugged firmly into the board

 

[NS P-68]

How is the flame when it is burning?

 

[bogieb]

If your exhaust hasn't been cleaned in a couple of years, it could absolutely be the problem. Ash or critters/nests could be choking it out.

Check that the plate for the ignitor area is on correctly - physically remove it and replace it. Also, make sure there isn't a bunch of ash under there (you didn't mention cleaning that area).

Make sure the plate that covers the combustion fan is on correctly, and the holding lever is all the way down.

I've never removed an ESP for cleaning, and never had an issue by just swiping it with a brush thru the exhaust (KOW). Doesn't mean the ESP can't have an issue,

 

[green wood]

Also check that the esp is plugged firmly into the board

im not sure what this means. from what im seeing the esp probe goes into the exhaust tube, and its bolted in with wires coming off of it. not sure what board you are referring too.

 

[green wood]

How is the flame when it is burning?

Good start up and good normal flame. works perfect like it alway has just goes out

 

[green wood]

If your exhaust hasn't been cleaned in a couple of years, it could absolutely be the problem. Ash or critters/nests could be choking it out.

Check that the plate for the ignitor area is on correctly - physically remove it and replace it. Also, make sure there isn't a bunch of ash under there (you didn't mention cleaning that area).

Make sure the plate that covers the combustion fan is on correctly, and the holding lever is all the way down.

I've never removed an ESP for cleaning, and never had an issue by just swiping it with a brush thru the exhaust (KOW). Doesn't mean the ESP can't have an issue,

Not arguing that, I just use the stove so rarely , only when its bitter cold, hard to imagine the pipe being clogged. I opened the T and there was barely anything in it.
NOthing like the one from the upstairs stove that we use constantly this time of year. We are burning the same pellots in both stoves and having no issues with the serenity.
I got down on the ground and looked at the outside exit of the stove exhaust...i have a grate over the pipe so nothing can get in or crawl I may have to try to get my fat butt under the deck and reverse blow with the leaf blower.
We have a ton of snow right now..not a easy task. One good thing is....its warmer this week so its not as crucial for the harman to be running.

 

[NS P-68]

I recently had the 6 blink issue with a Harman Accentra FS. Stove was cleaned and all the usual causes explored. I suspect a bad auger motor because it was noisy and just didn't seemed to be feeding enough pellets. Owner didn't agree because stove was lighting and burning but would shutdown with the 6 blink error. Finally the auger motor gave up and needed to be replaced. The 6 blink error seems to have gone away after that....🤞
Not saying thats your issue....and the first thing I would do is have your vent and stove entirely cleaned to rule that out. Cleaning is free... just throwing parts at it will get expensive $$

 

[Whitenuckler]

im not sure what this means. from what im seeing the esp probe goes into the exhaust tube, and its bolted in with wires coming off of it. not sure what board you are referring too.

We mean that the wires (twisted pair) plug into the control card. Remove your control card, check all the connectors, and it's a good time to clean the fines box.

 

[green wood]

We mean that the wires (twisted pair) plug into the control card. Remove your control card, check all the connectors, and it's a good time to clean the fines box.

ok ill look for these twisted wires, I have cleaned the fine box. Thank you.

 

[green wood]

We mean that the wires (twisted pair) plug into the control card. Remove your control card, check all the connectors, and it's a good time to clean the fines box.

I guess i cant get my head wrapped around how easy it starts up and burns.....IF it was plugged up out side. I watch the auger turning perfectly fine on start up. so i didnt think that is an issue either. Weird

 

[Sono]

If you have these, they might be bad

 

[Ssyko]

under the deck and reverse blow with the leaf blower.

By “reverse blowing” I am assuming you are going to suck air through the stove out through the vent pipe. Correct?

 

[green wood]

under the deck and reverse blow with the leaf blower.

By “reverse blowing” I am assuming you are going to suck air through the stove out through the vent pipe. Correct?

No I dont have that option. Ive seen many vids online where folks have gone out side and blew back into the stove exhaust pipe to clean out any build up. Cannot get the blower in the position to blow out from inside. Maybe if i came up with some flexible attachment, maybe.

 

[Tonyray]

Are you all talking about the leaf blower trick where u use a blower that also has a vacuum feature and attach to bottom of your outside exhaust to suck out any crud? lot of google videos on how to do this..

 

[Sono]

No I dont have that option. Ive seen many vids online where folks have gone out side and blew back into the stove exhaust pipe to clean out any build up. Cannot get the blower in the position to blow out from inside. Maybe if i came up with some flexible attachment, maybe.

If outside use compressed air. Ive vac'd and used a 200mph backpack blower on used stoves Ive brought home till supposedly clean.... but when you hit it with compressed air its a whole new beast... Youll be amazed at what comes out of it. Make sure to open the little fly ash doors inside and clean behind them, theres more in there than youd imagine.