Creosote with Pellet Stove?

[razz05]

I have the Harman P61A and have had it since January. My ex also has the same stove and has had his for 4 years now. Neither of us have come across this before, but today I'm noticing some creosote (black tarry like substance) in the stove. If anyone is familiar w/ the stove I have, I can kind of describe where it is. You have the burn pot w/ the "cover" on top and behind that are the 3 bricks. It's under the 3 bricks and above the "cover" to the burn pot. I cleaned the stove 4-5 days ago and noticed it a TINY bit, but it was just behind the "cover" to the burn pot. Now, it's all along the edge underneath the bricks all the way to both sides of the stove itself. Any ideas? Should I turn my stove off and have someone come look at it? It keeps catching on fire and it's making me nervous.

I forgot to add, that I am burning Westwood Premium Pellets that I got from Pelletsales.com. I've been burning them since about mid October. I ordered some for other people also and they haven't had any issues with the pellets doing this. It was really cold here yesterday, so I had the stove up pretty high (stove temp of 5-6, with feed rate of 4).

 

[crausch]

The creosote can form due to poor or incomplete combustion. Your fuel/air ratio is not correct. This can be caused by the feed rate being turned up too high. It sounds as you recently started burning it higher then in the past. It probably started when you turned it up but may have taken a day or two for the creosote to build and show.

If you have poor combustion you may notice partially burned pellets or even smoke coming out the vent termination on the outside. You will either need to cut back your maximum feed rate or you may need to adjust draft control which will control the combustion motor speed. If your feed rate is too high but you don't want to cut it back because you need the heat, try adjusting the combustion motor speed higher to gain the proper air/fuel ratio. This would stop the creosote. If you can't accomplish this, you may be asking to heat more than the stove is capable of. I only say this because I don't know how may square feet you are trying to heat, or how well insulated the area is.

 

[djarseneault]

The creosote can form due to poor or incomplete combustion. Your fuel/air ratio is not correct. This can be caused by the feed rate being turned up too high. It sounds as you recently started burning it higher then in the past. It probably started when you turned it up but may have taken a day or two for the creosote to build and show.

If you have poor combustion you may notice partially burned pellets or even smoke coming out the vent termination on the outside. You will either need to cut back your maximum feed rate or you may need to adjust draft control which will control the combustion motor speed. If your feed rate is too high but you don't want to cut it back because you need the heat, try adjusting the combustion motor speed higher to gain the proper air/fuel ratio. This would stop the creosote. If you can't accomplish this, you may be asking to heat more than the stove is capable of. I only say this because I don't know how may square feet you are trying to heat, or how well insulated the area is.

The draft adjustment on the Harmans is for the low draft only and has NO effect on the high draft. But getting the draft tested with a manometer or magnahelic is a good place to start diagnosis

 

[crausch]

ParotHead...Can you take a look at something for me. I was looking at the P61A manual. On page 17 (figure 22) they show the small plastic screw a.k.a. draft adjustment and they have this caption beside it:

C o m b u s t i o n Motor Speed Control, Low draft only set point. The small straight screwdriver slot is plastic; therefore, the unit can be adjusted while in operation.

This is what lead to my statement. I trust your experience so assuming I must be reading this wrong, can you explain what they are saying in the manual? Thanks!!

 

[razz05]

I called the place that I bought it from (it should still be under warranty). They're sending someone out to look at it this afternoon. I'll let you know what they say.

 

[Tinman]

I called the place that I bought it from (it should still be under warranty). They're sending someone out to look at it this afternoon. I'll let you know what they say.

Razz,
Harman's warranty does not cover cleaning issues make sure the exhaust pipe is cleaned top to bottom. The fines compartment is cleaned and if you are using outside air it is free of debris

 

[razz05]

The exhaust pipe? You mean the one outside? I did a thorough cleaning of everything before I started it this year.

 

[Wet1]

I'd vacuum the stove and clean the flue before they get there to be safe.

 

[razz05]

Well they showed up an hour early. They scraped all of the black stuff off and cleaned it out a little bit. They called the boss back and he pretty much said just to keep it scraped and if it happens again where it catches fire to call them. They said they've seen it happen before but not with the P version of the Harman stoves (whatever that means LOL). So, if it happens again I'm definitely calling them because now I'm wondering if there's something defective in my stove.

 

[crausch]

It sounds as though they cleaned it up, said they have seen it before, but offered no reason or solution...You are kind of no further then you were before except your stove is a little cleaner.

 

[djarseneault]

ParotHead...Can you take a look at something for me. I was looking at the P61A manual. On page 17 (figure 22) they show the small plastic screw a.k.a. draft adjustment and they have this caption beside it:

C o m b u s t i o n Motor Speed Control, Low draft only set point. The small straight screwdriver slot is plastic; therefore, the unit can be adjusted while in operation.

This is what lead to my statement. I trust your experience so assuming I must be reading this wrong, can you explain what they are saying in the manual? Thanks!!

These stoves use a reduced blower speed to decrease draft pressure for two reasons. first is during ignition, the lower draft is used to slow the air down as it goes across the ignitor, thus allowing it to "pick up" more heat from the ignitor and light the fire quicker. second, low draft is used during lower burns, because less fuel is being burned, so less air is needed. The low draft is adjustable via the potentiometer on the circuit board. Adjusting this dial will change the amount of voltage that is sent to the exhaust blower when the stove is on low draft. (less voltage=slower exhaust blower=less draft/more voltage=faster blower=more draft) During high draft the circuit board just sends full line voltage to the blower, this is not adjustable.

 

[djarseneault]

They said they've seen it happen before but not with the P version of the Harman stoves (whatever that means LOL)

The Accentra free standing stoves have a history of creosote problems (mostly the older ones) The P series (P-38,61,61A &68 are the cleanest and easiest to maintain of all their stoves. I have never seen creosote in a properly installed and properly functioning P series stove.

 

[Tinman]

Well they showed up an hour early. They scraped all of the black stuff off and cleaned it out a little bit. They called the boss back and he pretty much said just to keep it scraped and if it happens again where it catches fire to call them. They said they've seen it happen before but not with the P version of the Harman stoves (whatever that means LOL). So, if it happens again I'm definitely calling them because now I'm wondering if there's something defective in my stove.

Razz,
The P they mentioned means P38 P61, and P68. What you are probably seeing is nothing more than the flame guide being picked up as pellets are feeding and the flames sqeezing out the back. Older Harman stoves produced 3-5 years ago have a problem that Harman labled Sticky Stove. Sticky Stove is a build up of creosote up the feeder tube and into the feeder body. Harman has made many changes to the stove to stop this from occurring. Your stove being installed in Jan of 08 will have had the changes made to it. I have seen Sticky in in all P lines every stove except the harman insert. Harman has replaced sticky stoves that the warranty has expired on with out any problems. So enjoy your stove Harman stands behind their stoves

 

[razz05]

Well they showed up an hour early. They scraped all of the black stuff off and cleaned it out a little bit. They called the boss back and he pretty much said just to keep it scraped and if it happens again where it catches fire to call them. They said they've seen it happen before but not with the P version of the Harman stoves (whatever that means LOL). So, if it happens again I'm definitely calling them because now I'm wondering if there's something defective in my stove.

Razz,
The P they mentioned means P38 P61, and P68. What you are probably seeing is nothing more than the flame guide being picked up as pellets are feeding and the flames sqeezing out the back. Older Harman stoves produced 3-5 years ago have a problem that Harman labled Sticky Stove. Sticky Stove is a build up of creosote up the feeder tube and into the feeder body. Harman has made many changes to the stove to stop this from occurring. Your stove being installed in Jan of 08 will have had the changes made to it. I have seen Sticky in in all P lines every stove except the harman insert. Harman has replaced sticky stoves that the warranty has expired on with out any problems. So enjoy your stove Harman stands behind their stoves

So, should I call to get the stove replaced?

 

[Tinman]

Well they showed up an hour early. They scraped all of the black stuff off and cleaned it out a little bit. They called the boss back and he pretty much said just to keep it scraped and if it happens again where it catches fire to call them. They said they've seen it happen before but not with the P version of the Harman stoves (whatever that means LOL). So, if it happens again I'm definitely calling them because now I'm wondering if there's something defective in my stove.

Razz,
The P they mentioned means P38 P61, and P68. What you are probably seeing is nothing more than the flame guide being picked up as pellets are feeding and the flames sqeezing out the back. Older Harman stoves produced 3-5 years ago have a problem that Harman labled Sticky Stove. Sticky Stove is a build up of creosote up the feeder tube and into the feeder body. Harman has made many changes to the stove to stop this from occurring. Your stove being installed in Jan of 08 will have had the changes made to it. I have seen Sticky in in all P lines every stove except the harman insert. Harman has replaced sticky stoves that the warranty has expired on with out any problems. So enjoy your stove Harman stands behind their stoves

So, should I call to get the stove replaced?

Razz,
Your stove is new enough that it has the newer feeder body. If you called the shop to report a creosote build up in your stove I'm sure they checked it for any signs of sticky stove. All Harman service people have been trained to inspect the stoves for any signs of sticky stove. Most of the stoves that had the problem have been replaced. So enjoy that stove keep it clean and it will run for many years.