# Harman P43 Error Code 6 blinks



## Harman_N_VT (Jan 22, 2014)

Hi all.  First post here.. I have read all the posts that I could find in here and other fora, and have followed all of the advice, as well as what's provided in the owner's manual.

A little history.. I have been running the P43 fo 4 or 5 years now with very few problems.  I use about 2 ton per season and have been burning Curran hardwood/softwood for the last 3 years and have had quite good luck with them, even if they are not the lowest ash product out there.  I have about a 3ft rise with 2 45s and a cleanout T on the first.  I also have the OAK from day one. The stove was professionally installed by the dealer.  I run in room temp mode and in dead of winter I use the manual ignition mode.  I clean the burn pot quite religiously, but I probably don't scrape down as often as I should.  My exhaust flue runs nice and clean after finally ditching the worthless screen on the end cap a couple of years ago.

So yesterday morning I get up and it cold as heck.  Stove died and was blinking 3 (ESP fault).  My thought process was, "I know it's due for a cleaning" and got right to it.  Heat exchanger, exhaust port to the ESP and other areas had the usual caked on fluff and the burn pot had a pretty good build up of carbon.  It's been a hard winter and the stove's been running constantly.  I also ran the 3" brush through and cleaned out the T.  Everything looks normal and cleaned up nice.  When I do scrape and clean I do a very thorough job.   I fire the stove back up and it runs for about 45 minutes or so, and then shuts itself down and blinks 6.  So like a good boy, I follow all of the suggestions in the OM.  I tried with OAK disconnected, still same scenario, runs for 45 mins and 6 blinks.  Inlet flapper is nice and free.  Ran a 1/2" vacuum probe that I cobbled together, down the inlet in the back of the stove, seems nice and clean.  Did the same under the burn pot around the ignitor and down the inlet ports as far as I could get.  It did suck up  a little ash debris, but nothing close to obstructing.  I clean out the finds catch and it had alot of saw dust, but I cleaned very thoroughly.    I'm starting to pull my hair out.  Any ideas?!!  Thanks in advance...


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## mikkeeh (Jan 22, 2014)

Check the cover on the fines box....it can cause a lot of problems if its not on quite right and doesn't seal.    Check the gasket on the hopper lid.  A crushed pellet will leave a divot in the gasket and cause a leak.   Mine looked fine, but just started leaking on the hinge side.


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## Harman_N_VT (Jan 23, 2014)

mikkeeh said:


> Check the cover on the fines box....it can cause a lot of problems if its not on quite right and doesn't seal.    Check the gasket on the hopper lid.  A crushed pellet will leave a divot in the gasket and cause a leak.   Mine looked fine, but just started leaking on the hinge side.



I checked these items one more time and the hopper lid gasket is perfect.  It's soft, pliable and clean.  The fines box cover is properly fastened as well. 

I meant to mention, also, that the flame is short and spiked instead of the usual soft dancing flame that varies in size depending on the amount of call for heat.  Ash is a little more course than usual.  Something has changed but I still am at a loss..

Thanks for your suggestion...


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## mepellet (Jan 23, 2014)

Soft dancing flame sounds like an airflow issue.


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## mikkeeh (Jan 23, 2014)

Is it possible that the flapper on the  air intake is freezing and restricting the airflow of the oak?   I haven't had that problem, but when it gets really cold I can see where condensation MIGHT be an issue?   Door and ash door gaskets check OK?


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## HarmanManP43 (Jan 23, 2014)

OP is saying that his flame is NOW short and spiked an not its usual large flame.  However it should never be a soft dancing flame.

Sounds to me like an actual ESP probe issue if everything is truely clean.  The stove is running the combustion blower too high (most likely due to faulty ESP readings) casuing the short spiked flame.  Airflow restriction is not the issue you have the opposite.

Replace the ESP its not expensive and take 10 mins.  This could also be a Control board issue but i would replace the cheaper component first.


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## Harman_N_VT (Jan 23, 2014)

HarmanManP43 said:


> OP is saying that his flame is NOW short and spiked an not its usual large flame.  However it should never be a soft dancing flame.
> 
> Sounds to me like an actual ESP probe issue if everything is truely clean.  The stove is running the combustion blower too high (most likely due to faulty ESP readings) casuing the short spiked flame.  Airflow restriction is not the issue you have the opposite.
> 
> Replace the ESP its not expensive and take 10 mins.  This could also be a Control board issue but i would replace the cheaper component first.



Thanks HarmanMan and everyone else who replied.  I guess I didn't describe a normal flame very well, but HarmanMan has it right.  It is now short and spiked.  I will run out and pickup a new ESP tomorrow and report back here on it's effect (hopefully cured!).  I see I can get one on Amazon for ~$81.  Hopefully the local dealer won't be too far off that mark.  Thanks again to all who responded...


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## mepellet (Jan 23, 2014)

I understood that the flame is not soft dancing anymore. But when it was, I would think airflow issue. Might not be related to the current issue but maybe. I'm no expert.


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## Harman Lover 007 (Jan 23, 2014)

HarmanManP43 said:


> The stove is running the combustion blower too high (most likely due to faulty ESP readings) casuing the short spiked flame.


FYI, the combustion blower speed is NOT controlled by the ESP and is not variable. It's either running or it isn't.  A 6 blink status is incomplete combustion and I would be looking at a venting issue.


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## P38X2 (Jan 23, 2014)

I'd be concerned about the 3 blink as well.


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## Harman Lover 007 (Jan 23, 2014)

P38X2 said:


> I'd be concerned about the 3 blink as well.


I read it as his 3 blink was solved and now he has a 6 blink....the point I'm  trying to make is that the ESP doesn't control the combustion fan speed.


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## P38X2 (Jan 23, 2014)

I agree with your point regarding the comb speed.

Im suggesting the 3 blink could cause the 6 blink if the ESP was failing.

ETA- HARMAN_N_VT, you cleaned your venting good, correct?


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## Harman_N_VT (Jan 23, 2014)

P38X2 said:


> I agree with your point regarding the comb speed.
> 
> Im suggesting the 3 blink could cause the 6 blink if the ESP was failing.
> 
> ETA- HARMAN_N_VT, you cleaned your venting good, correct?




Yes the intake and exhaust are clean as a whistle now.  Flapper is working fine.  I have disconnected the OAK until I get this resolved, and then I'll connect it again. I attribute the initial 3 blink fail to a dirty stove, but I suppose it could be a real ESP fail.  I have seen the 3 blinks in the past from a dirty exhaust port.


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## HarmanManP43 (Jan 23, 2014)

Harman Lover 007 said:


> FYI, the combustion blower speed is NOT controlled by the ESP and is not variable. It's either running or it isn't.  A 6 blink status is incomplete combustion and I would be looking at a venting issue.





The ESP is the only sensor actually on the stove and is therefore the only way the control board knows whats going on. Combustion speed is most definitely variable….


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## HarmanManP43 (Jan 23, 2014)

I'm not sure why everyone is suggesting a dirty exhaust when the OP is describing a burn considerably more vigorous then what he had before...


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## P38X2 (Jan 23, 2014)

HarmanManP43 said:


> The ESP is the only sensor actually on the stove and is therefore the only way the control board knows whats going on. Combustion speed is most definitely variable….


My 2 knob 38 is variable, but I've never seen, or more accurately, heard my newer (since sold) 38 or my 68 have any variation.


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## P38X2 (Jan 23, 2014)

When I had a 3 blink, it was a failed ESP on a 5 day old stove. Burn looked fine, but dist blower on/off constantly.


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## smwilliamson (Jan 23, 2014)

HarmanManP43 said:


> The ESP is the only sensor actually on the stove and is therefore the only way the control board knows whats going on. Combustion speed is most definitely variable….


It's not variable


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## smwilliamson (Jan 23, 2014)

Harman_N_VT said:


> Hi all.  First post here.. I have read all the posts that I could find in here and other fora, and have followed all of the advice, as well as what's provided in the owner's manual.
> 
> A little history.. I have been running the P43 fo 4 or 5 years now with very few problems.  I use about 2 ton per season and have been burning Curran hardwood/softwood for the last 3 years and have had quite good luck with them, even if they are not the lowest ash product out there.  I have about a 3ft rise with 2 45s and a cleanout T on the first.  I also have the OAK from day one. The stove was professionally installed by the dealer.  I run in room temp mode and in dead of winter I use the manual ignition mode.  I clean the burn pot quite religiously, but I probably don't scrape down as often as I should.  My exhaust flue runs nice and clean after finally ditching the worthless screen on the end cap a couple of years ago.
> 
> So yesterday morning I get up and it cold as heck.  Stove died and was blinking 3 (ESP fault).  My thought process was, "I know it's due for a cleaning" and got right to it.  Heat exchanger, exhaust port to the ESP and other areas had the usual caked on fluff and the burn pot had a pretty good build up of carbon.  It's been a hard winter and the stove's been running constantly.  I also ran the 3" brush through and cleaned out the T.  Everything looks normal and cleaned up nice.  When I do scrape and clean I do a very thorough job.   I fire the stove back up and it runs for about 45 minutes or so, and then shuts itself down and blinks 6.  So like a good boy, I follow all of the suggestions in the OM.  I tried with OAK disconnected, still same scenario, runs for 45 mins and 6 blinks.  Inlet flapper is nice and free.  Ran a 1/2" vacuum probe that I cobbled together, down the inlet in the back of the stove, seems nice and clean.  Did the same under the burn pot around the ignitor and down the inlet ports as far as I could get.  It did suck up  a little ash debris, but nothing close to obstructing.  I clean out the finds catch and it had alot of saw dust, but I cleaned very thoroughly.    I'm starting to pull my hair out.  Any ideas?!!  Thanks in advance...


ESP probe man. First code gave you the clue, #6 later on confirmed that the stove thinks its running cooler than it actually is. Problem being, nothing is monitoring the monitoring device. Did you get the 6 blink more than once? The 6 blink can also come from an air leak from the fines box, feeder by-pass tube or hopper lid seal. May have been just dirty and then compounded by a user error in cleaning. Try to get the 6 blink again. If you get it and the three things I mentioned are good, buy an ESP with confidence.


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## HarmanManP43 (Jan 23, 2014)

P38X2 said:


> My 2 knob 38 is variable, but I've never seen, or more accurately, heard my newer (since sold) 38 or my 68 have any variation.



I'm basing my view on two things, The installation manual has two draft tests needed when installing the stove.  High (around -1.0 inch WC) and low which must be adjusted by the installer to between -0.35 to -0.45 WC.  This leads to be believe the control board controls the draft based on readings received from the ESP (the only way the stove has any idea whats happening)

My second thought is every stove i have previously had had a manual draft level to control burn.  If harman just ran their combustion blower on full speed 24/7 you would have a horribly inefficient stove on the lower settings.  

Harmans are pricey because they are very easy to operate as the control board makes all these decisions for the owner.

I own a draft meter and test my stove after every full clean.  Takes 2 mins and lets me know that everything is working perfectly.

Just my 2 cents, 

I'm still convinced its a ESP fault as the 6 blinks are an ESP reading bad burn.  If by a small chance its not the ESP i will go with a bad board.  I've seen plenty this year already.


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## HarmanManP43 (Jan 23, 2014)

smwilliamson said:


> It's not variable



Surprised by this.  I'll hold my hands up if i'm wrong but seems to be a very basic lack of control of the burn if this is the case.


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## smwilliamson (Jan 23, 2014)

HarmanManP43 said:


> I'm basing my view on two things, The installation manual has two draft tests needed when installing the stove.  High (around -1.0 inch WC) and low which must be adjusted by the installer to between -0.35 to -0.45 WC.  This leads to be believe the control board controls the draft based on readings received from the ESP (the only way the stove has any idea whats happening)
> 
> My second thought is every stove i have previously had had a manual draft level to control burn.  If harman just ran their combustion blower on full speed 24/7 you would have a horribly inefficient stove on the lower settings.
> 
> ...


The ESP is a thermocouple that measures heat. Not air velocity. It is constant. The installer can trim the voltage down if the stove has too mush draft but there is no control to give it more...just less, and it spins that fast from power on to power down....unless you open the door, the stove then loses suction and the motor slows up a bit. If you put the Harman diagnostic on the stove while its running you'll see that its usually a constant 119v (unless you trim it down)


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## HarmanManP43 (Jan 23, 2014)

smwilliamson said:


> The ESP is a thermocouple that measures heat. Not air velocity. It is constant. The installer can trim the voltage down if the stove has too mush draft but there is no control to give it more...just less, and it spins that fast from power on to power down....unless you open the door, the stove then loses suction and the motor slows up a bit. If you put the Harman diagnostic on the stove while its running you'll see that its usually a constant 119v (unless you trim it down)



Why have a high and low draft test when installing the stove then?  Wouldn't they just have a one WC number they want the installer to achieve?


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## smwilliamson (Jan 23, 2014)

HarmanManP43 said:


> Why have a high and low draft test when installing the stove then?  Wouldn't they just have a one WC number they want the installer to achieve?


every instalaltion is different and to be truthfull...that high end number is hard to achieve sometimes cause you can only trim so low.


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## HarmanManP43 (Jan 23, 2014)

smwilliamson said:


> every instalaltion is different and to be truthfull...that high end number is hard to achieve sometimes cause you can only trim so low.



My stove is cranking right now did a draft test came back at -0.9 WC, turned it down (Room temp Manual) WC dropped to -0.45

Now this is what i knew it did having tested it previously.  Maybe it only drops to this for the maintenance burn.


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## smwilliamson (Jan 23, 2014)

HarmanManP43 said:


> My stove is cranking right now did a draft test came back at -0.9 WC, turned it down (Room temp Manual) WC dropped to -0.45
> 
> Now this is what i knew it did having tested it previously.  Maybe it only drops to this for the maintenance burn.


fire creates positive pressure don't you know. Thats why it varies from low to high fires.


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## HarmanManP43 (Jan 23, 2014)

smwilliamson said:


> fire creates positive pressure don't you know. Thats why it varies from low to high fires.



Fire was the same size… i tested as soon as i turned the temperature down and the fire hadn't had a chance to change.  Anyways bored of going round in circles over this.  Been an interesting discussion.


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## P38X2 (Jan 23, 2014)

Well at the risk of being wrong in yet another thread regarding a possible ESP failure, I'm still gonna say it's a failing ESP. 

I gotta get it right one of these times!


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## smwilliamson (Jan 24, 2014)

Where are you checking from and with what?


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## Harman Lover 007 (Jan 24, 2014)

HarmanManP43 said:


> The ESP is the only sensor actually on the stove and is therefore the only way the control board knows whats going on. Combustion speed is most definitely variable….


Nope...


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## Harman Lover 007 (Jan 24, 2014)

HarmanManP43 said:


> Fire was the same size… i tested as soon as i turned the temperature down and the fire hadn't had a chance to change.  Anyways bored of going round in circles over this.  Been an interesting discussion.


Apologies for boring you.....but some of us just hate it when bad information starts here and takes on a life of it's own. Do as Scott says..grab a voltmeter and stick it on the combustion blower leads and adjust away using your theory. The input voltage will not change and therefore neither will the combustion motor speed.


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## HarmanManP43 (Jan 24, 2014)

smwilliamson said:


> Where are you checking from and with what?


 
Dwyer Air meter in the draft test hole. 14mm bolt on left of stove.


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## HarmanManP43 (Jan 24, 2014)

Harman Lover 007 said:


> Apologies for boring you.....but some of us just hate it when bad information starts here and takes on a life of it's own. Do as Scott says..grab a voltmeter and stick it on the combustion blower leads and adjust away using your theory. The input voltage will not change and therefore neither will the combustion motor speed.


 
Do you run your stove in Room temp manual? have you tested this yourself?  i will do this out of curiousity when i get home.

I do all my testing with a draft meter as this is what is important for burn. Multimeters are for fault finding and i have not had any faults with this stove. I will report back but i'm sure i'll find that when the stove goes into a maintenace burn that voltage across the motor will drop.

I completely agree with bad information however i am seeing the opposite of what you gentleman are describing.  I only want the facts if i'm wrong i will be the first to hold my hands up.


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## Harman Lover 007 (Jan 24, 2014)

HarmanManP43 said:


> Do you run your stove in Room temp manual? have you tested this yourself?  i will do this out of curiousity when i get home.
> 
> I do all my testing with a draft meter as this is what is important for burn. Multimeters are for fault finding and i have not had any faults with this stove. I will report back but i'm sure i'll find that when the stove goes into a maintenace burn that voltage across the motor will drop.
> 
> I completely agree with bad information however i am seeing the opposite of what you gentleman are describing.  I only want the facts if i'm wrong i will be the first to hold my hands up.


I won't be afraid to admit I'm wrong either, if that is the case, but in 18 years of Harman ownership I've never seen or heard my combustion blower slow down.
My distribution blower slows down when running in Room Temp manual when going into maintenance burn.


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## HarmanManP43 (Jan 24, 2014)

Harman Lover 007 said:


> I won't be afraid to admit I'm wrong either, if that is the case, but in 18 years of Harman ownership I've never seen or heard my combustion blower slow down.
> My distribution blower slows down when running in Room Temp manual when going into maintenance burn.


 
Agreed on the distribution blower as that we can all here ramping down. I'm basing my views on negative pressure( which is only effected by the combustion blower) in the stove and on what the installation manual says.  I agree that a voltmeter across the combustion motor is the sure fire way to confirm or deny this.

A lot of people are on here because they want to help others and have an interest in the stoves and thats why i am here.  I have no questions of my own but solely here to answer others and fault find.  Last thing i want to do is give bad information or p**s people off!  Hope none of you have taken my insistence on this as an attack on your experience.

All the best.

James


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## Harman_N_VT (Jan 24, 2014)

Well the verdict is in.  I picked up a new ESP probe from the dealer and installed it 3pm (EST) and it's been running for well over an hour without a fault.  Also the flame looks normal and the heat is cranking out.  It just kicked down to maintenance flame as I run ignitor in manual and stove in room temp.  Hopefully I'm not premature in reporting we are good to go, but I do think we are. 

A big THANK YOU to everyone who posted and to HarmanMan for hitting the nail on the head.  The service guy explained it to me that if
the ESP prematurely senses peak temp, the fire never gets big enough for complete burn and thus the error code 6...

Cheers!


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## P38X2 (Jan 24, 2014)

Nice. Glad to hear you're back up and running.

I was right this time! Pfff, knew it


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## Harman_N_VT (Jan 25, 2014)

P38X2 said:


> Nice. Glad to hear you're back up and running.
> 
> I was right this time! Pfff, knew it



Yes you were!!  Woke up this morning to a nice warm house heated by our P43..  Woohoo!!


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## HarmanManP43 (Jan 25, 2014)

Harman_N_VT said:


> Well the verdict is in.  I picked up a new ESP probe from the dealer and installed it 3pm (EST) and it's been running for well over an hour without a fault.  Also the flame looks normal and the heat is cranking out.  It just kicked down to maintenance flame as I run ignitor in manual and stove in room temp.  Hopefully I'm not premature in reporting we are good to go, but I do think we are.
> 
> A big THANK YOU to everyone who posted and to HarmanMan for hitting the nail on the head.  The service guy explained it to me that if
> the ESP prematurely senses peak temp, the fire never gets big enough for complete burn and thus the error code 6...
> ...



Glad it was an easy fix.


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