Fixing my PB105

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.

Former Farmer

Minister of Fire
Apr 12, 2008
608
NE Wisconsin
Dip switches set for Auto startup, +43 seconds for feed amount (1,2,3 is on,off,on)

Does the unit feed pellets after the initial feed for startup? I am wondering if the ESP is not seeing a high enough number and shutting the unit down. A completely cold boiler will take more to get the ESP up to a certain temperature because of the water drawing that much heat off of the flame.

You could try setting your DIP switches to 1 - on, 2 - on, 3 - off to set +64 seconds for the "charge" cycle. You will have to watch and see how many pellets are actually being loaded into the firepot.
 

White00s10

New Member
Feb 24, 2021
33
Concord NY
Does the unit feed pellets after the initial feed for startup? I am wondering if the ESP is not seeing a high enough number and shutting the unit down. A completely cold boiler will take more to get the ESP up to a certain temperature because of the water drawing that much heat off of the flame.

You could try setting your DIP switches to 1 - on, 2 - on, 3 - off to set +64 seconds for the "charge" cycle. You will have to watch and see how many pellets are actually being loaded into the firepot.



Exactly. The unit goes into startup, feeds its initial pellet load based on the dip switch settings, than lights it, but once that lights, it stops feeding and goes out. Ive got a new esp Im planning on trying. Is it possible its also draft related? Im running a 4"-3" home made OAK and im wondering if its limiting the amount of draft in the stove, and its only remediated when exhaust gas gets up to temp tp pull sufficient draft as it exits the chimney
 

johneh

Minister of Fire
Dec 19, 2009
3,754
Eastern Ontario
Don.t know your system but to me, it sounds like the proof of fire
snap disc or whatever is used is not working. Does not show that a fire has started
 

Mr._Graybeard

Feeling the Heat
Apr 27, 2012
367
Southeast Wisconsin
Exactly. The unit goes into startup, feeds its initial pellet load based on the dip switch settings, than lights it, but once that lights, it stops feeding and goes out. Ive got a new esp Im planning on trying. Is it possible its also draft related? Im running a 4"-3" home made OAK and im wondering if its limiting the amount of draft in the stove, and its only remediated when exhaust gas gets up to temp tp pull sufficient draft as it exits the chimney
I didn't understand that the boiler was shutting down right after ignition. If you haven't replaced the ESP it's probably worth trying. I think a bad vacuum switch wouldn't allow any pellet feed at all.
 

Former Farmer

Minister of Fire
Apr 12, 2008
608
NE Wisconsin
I don't think that the OAK is the issue. The exhaust fan may not be pulling enough air through the unit. Have you checked all of your gaskets to make sure you don't have any air leaks? Is the damper in the air intake working properly?

I know you mentioned that you had cleaned the unit. Did you clean everything? I am wondering if the slide area for the pellet feeder mechanism is plugged and not feeding enough pellets into the auger. Did you pull the exhaust fan and clean that area and the fins on the fan as well? I am assuming that you did all of this, but just need to check to make sure that the whole unit is clean.

I thought that there are two different ESP sensors that Harman was using. One has red wires and the other had black wires. I don't know if there is any difference or not. Mine has the red wires.

You may also look at connections on the control board. ONLY DO THIS WITH THE POWER TURNED OFF TO THE UNIT. Make sure all of the wire connectors are tight and not corroded.
 
Last edited:

White00s10

New Member
Feb 24, 2021
33
Concord NY
I don't think that the OAK is the issue. The exhaust fan may not be pulling enough air through the unit. Have you checked all of your gaskets to make sure you don't have any air leaks? Is the damper in the air intake working properly?

I know you mentioned that you had cleaned the unit. Did you clean everything? I am wondering if the slide area for the pellet feeder mechanism is plugged and not feeding enough pellets into the auger. Did you pull the exhaust fan and clean that area and the fins on the fan as well? I am assuming that you did all of this, but just need to check to make sure that the whole unit is clean.

I thought that there are two different ESP sensors that Harman was using. One has red wires and the other had black wires. I don't know if there is any difference or not. Mine has the red wires.

You may also look at connections on the control board. ONLY DO THIS WITH THE POWER TURNED OFF TO THE UNIT. Make sure all of the wire connectors are tight and not corroded.
Yes sir, did a thorough cleaning when i moved the stove. All the nooks and crannies were shop vacuumed out and scraped. I cleaned the fines trap on the auger, that little plate to the right of the ash pan door, and i pulled the exhaust fan and scraped and cleaned it and the chamber. I also took a steel bottle brush and ran it up as far as i could get it into the heat exchanger. The intake flap is also working.

Mine is an earlier unit from Nov 2006, and it has the black esp. i ordered a new esp, and the PN came with one that has a red wire. I believe i will have to change dip switch #5 for this to work with my unit. Plans are to change the esp and see what the outcome is before I try anything else.
 
  • Like
Reactions: Former Farmer

White00s10

New Member
Feb 24, 2021
33
Concord NY
Yes sir, did a thorough cleaning when i moved the stove. All the nooks and crannies were shop vacuumed out and scraped. I cleaned the fines trap on the auger, that little plate to the right of the ash pan door, and i pulled the exhaust fan and scraped and cleaned it and the chamber. I also took a steel bottle brush and ran it up as far as i could get it into the heat exchanger. The intake flap is also working.

Mine is an earlier unit from Nov 2006, and it has the black esp. i ordered a new esp, and the PN came with one that has a red wire. I believe i will have to change dip switch #5 for this to work with my unit. Plans are to change the esp and see what the outcome is before I try anything else.
Well, I tried the new esp. It was shot from the start. Probably why it was only 17.00 on amazon. As soon as I plugged the new esp in and flipped the power on, the blower kicked on and the unit started to randomly feed pellets, even with the min knob turned too off, no matter what position I had dip switch 5 at. Put the old esp on and it started up normal ( like it has been).

I ordered 2 new esp's from Harman right after. No sense in fighting cheap aftermarket replacements.
 

White00s10

New Member
Feb 24, 2021
33
Concord NY
Ordered a new esp from harman. Its the right part no according to the book

3-20-00844

As soon as i plug it in and it gets power, the blower motor starts up. Even with both dials off. And dip switch 5 is set to "on" both probes have red wires. Am I looking into a bad board?
 
  • Like
Reactions: Washed-Up

Washed-Up

Minister of Fire
Nov 5, 2011
790
Kananaskis,Alberta, Canada
Wondering if you’ve cleaned the pots? Pull the dials off and spray the post areas with contact cleaner then roll them back and forth then repeat
 

Former Farmer

Minister of Fire
Apr 12, 2008
608
NE Wisconsin
Does the blower continue to run or only run for a second or so?

When I turn power on to my boiler, the blower runs for a second or so. This is with the igniter set to manual and the min temp set to off.
 

Former Farmer

Minister of Fire
Apr 12, 2008
608
NE Wisconsin
Ordered a new esp from harman. Its the right part no according to the book

3-20-00844

As soon as i plug it in and it gets power, the blower motor starts up. Even with both dials off. And dip switch 5 is set to "on" both probes have red wires. Am I looking into a bad board?

Did you try it with the dip switch set to off?

I am wondering if your board is does not have the firmware for the red ESP probe, being that you had the black probe originally.
 

White00s10

New Member
Feb 24, 2021
33
Concord NY
Did you try it with the dip switch set to off?

I am wondering if your board is does not have the firmware for the red ESP probe, being that you had the black probe originally.
I tried it with dip switch 5 in either position and the end result is the same. I bought a new board thru earth sense, so well see how it goes after that comes in and I install it.
 

White00s10

New Member
Feb 24, 2021
33
Concord NY
Well brand new board showed up today. Had a birthday party in Rochester for the girlfriends nephew. Got home at 8:30 and swapped it out quick. Turned the unit on, and away she went. Started feeding, ignited, and were cruising up to the max temp of 185. Hopefully this was all that was wrong with it. (Has to be since Ive replaced damn near everything else lol!)
 
  • Like
Reactions: Mr._Graybeard

Former Farmer

Minister of Fire
Apr 12, 2008
608
NE Wisconsin
Glad to hear that you have it up and running!

Now that you have basically rebuilt the unit, it should be trouble free for quite a while hopefully. Enjoy and keep us updated as to how everything is working for you.
 

White00s10

New Member
Feb 24, 2021
33
Concord NY
Took some time this A.M. to wrap the pipes and keep them from shedding heat in the basement. So far the units given me almost 1 week of trouble free operation! Thanks again guys for all your help. I couldn't have gotten this thing up and running without ya!
20211024_105236.jpg
20211024_105300.jpg
 

Mr._Graybeard

Feeling the Heat
Apr 27, 2012
367
Southeast Wisconsin
Great to hear you got the boiler running right. I think with the way fossil fuel prices are going, pellets are going to be an economical heating option again. I picked up four tons this fall at $210 per. Plus, the boiler is pretty efficient.

A couple parting observations: If you're piggybacking this unit with another hydronic heating plant, you may need a bigger expanaion tank than the one I see in the pic. I was having trouble with water leaking out of the pressure relief until I installed an expansion tank with more capacity.

Second, as I think Former Farmer observed, you need to keep that combustion blower fan CLEAN, especially if you're burning ashy pellets. I usually tackle it at least every six weeks, and find it easiest to remember if I do it on a monthly basis. If you don't stay on it, you're likely to get explosive ignitions, which don't do any real damage but will vent a lot of smoke into the house.
 

White00s10

New Member
Feb 24, 2021
33
Concord NY
Both systems are together, but seperate. When the pellet boilers running, it uses both expansion tanks ( the one for the pellet boiler and the one for the oil boiler) otherwise it was the same thing as you described,leaking out the pressure valve.

I just realized my blower doesnt have a gasket, is this a problem?
 

Former Farmer

Minister of Fire
Apr 12, 2008
608
NE Wisconsin
When I added the PB105 into my existing system, I just added a second expansion tank instead of replacing the old one with a larger one.

Glad everything is working for you. Just in time for the cooler weather starting (here at least).

Graybeard, where did you get pellets for $210 per ton? Everything I am seeing in this ares is north of $235 per ton.

Have a safe and happy heating season.
 

Mr._Graybeard

Feeling the Heat
Apr 27, 2012
367
Southeast Wisconsin
I took advantage of an early buy at my local Tractor Supply. I think the regular price is $4.69 a bag, but they often have bulk discounts.

My store has been getting pellets from a plant in Ontario that are pretty good.
 

stephenmoore

Member
Feb 23, 2008
82
Halifax, NS Canada
Took some time this A.M. to wrap the pipes and keep them from shedding heat in the basement. So far the units given me almost 1 week of trouble free operation! Thanks again guys for all your help. I couldn't have gotten this thing up and running without ya! View attachment 283863 View attachment 283864
Glad to see you got it up and running, I have a PB105 from 2006-7 as well.
I had loads of problems with the finned igniters and just gave up on them, I light and run mine manually. I wasn't prepared to shell out the money for the new pressure igniter.
Also eventually replaced the ESP after it wouldn't stay lit.
And I'm on my second burn pot after the first one bubbled and cracked, I actually got a local fabrication shop to make me a new one with stainless steel based on the new design, 6 years later its still going strong.
Its too bad Harman stopped trying to improve the design, once you get the bugs ironed out they are pretty reliable.
Once winter gets going here I let mine run all the time in manual mode, I have the DHW coil in mine as well to pre heat my water for showers etc.
I went through 7 or eight igniters the first year until the warranty ended.
Hope you continue to have good luck
 

Mr._Graybeard

Feeling the Heat
Apr 27, 2012
367
Southeast Wisconsin
Looking again at the way you have the vent set up with that little vertical attachment, I would take that off and just add a grid made of 1/2-inch hardware cloth to the flue end to keep the varmints out. There's a flue cleanout procedure called the "leaf blower trick" that cleans out the fly ash nicely. I'm not sure you can avail yourself of that with the little capped chimney.

Search this forum for "leaf blower trick" and you'll get the lowdown.
 

White00s10

New Member
Feb 24, 2021
33
Concord NY
Looking again at the way you have the vent set up with that little vertical attachment, I would take that off and just add a grid made of 1/2-inch hardware cloth to the flue end to keep the varmints out. There's a flue cleanout procedure called the "leaf blower trick" that cleans out the fly ash nicely. I'm not sure you can avail yourself of that with the little capped chimney.

Search this forum for "leaf blower trick" and you'll get the lowdown.
That short pipe with the s curve on it is the Fresh air vent; it actually has a 4" pvc drainage grate screwed and siliconed into it to keep the random varmints out of it. For the main chimney I went with duravent 4" straight up through the soffit, so i got decent draft. I was going to give it another month or two and try the leaf blower trick after I burn my 1st ton.