Harmon PB 105 Boiler- Won't feed pellets

[Heat Ray]

Hello,
I attempted to start up my PB 105 today for what may be its last winter, according to my local dealer and service provider. I have had a variety of issues of the years with it, as many have, but I haven't encountered this before. When I powered it up and turned the dial to get things going, I got nothing. The auger wouldn't turn. Nothing even seemed like it was attempting to fire up. I'm hoping this is a simple wiring issue. When it was serviced in September, everything worked fine when tested.
Anyone have some insight into this dilemma?
Thanks

 

[railfanron]

Perhaps the fuse on the control board. If the igniter is wearing out it could blow the fuse on startup and that would give you nothing. No lights or any sounds of a startup.
Ron

 

[Heat Ray]

Perhaps the fuse on the control board. If the igniter is wearing out it could blow the fuse on startup and that would give you nothing. No lights or any sounds of a startup.
Ron

Thanks. I will give that a shot. A couple lights do come on, but again nothing else. Not even a whir.

 

[Heat Ray]

Perhaps the fuse on the control board. If the igniter is wearing out it could blow the fuse on startup and that would give you nothing. No lights or any sounds of a startup.
Ron

Hello,
I the fuse looks fine. Open to any other ideas. Not sure how to get this going

 

[SidecarFlip]

Call your service man and let him diagnose and repair it.

 

[SciGuy]

Hello,
I attempted to start up my PB 105 today for what may be its last winter, according to my local dealer and service provider. I have had a variety of issues of the years with it, as many have, but I haven't encountered this before. When I powered it up and turned the dial to get things going, I got nothing. The auger wouldn't turn. Nothing even seemed like it was attempting to fire up. I'm hoping this is a simple wiring issue. When it was serviced in September, everything worked fine when tested.
Anyone have some insight into this dilemma?
Thanks

Hi Ray,

From looking at the parts available, appears that your boiler uses a combustion blower and vacuum switch just like the Harman pellet stoves so many of us have. If the combustion blower doesn't spool up the vacuum switch won't be actuated and the pellets won't be fed. Can you get access to the combustion blower to see if it spins freely by hand? I've seen stoves where the blower wheel was "stuck" by accumulated and hardened ash. When freed up they ran fine, actuated the the vacuum switch and bob's you uncle, things ran fine. Barring the blower not turning, a blockage in the air intake out exhaust piping could cause the same lack of vacuum.

YMMV,

Hugh

 

[SidecarFlip]

Pull it, clean the blower wheel with a brush carefully because it's brittle from the heat, clean the plenum it's in and lubricate the bearings with light machine oil (3-1) works well. Re install it using the old gasket or a bead of Red RTV (allowing the RTV to cure before putting it back on (makes removing it later, much easier). make sure the venting pipe is clean as well.

Number one cause of stove / pellet boiler issues is dirty venting and tied up combustion blower issues followed by tied up distribution blower issues. Maintaining the mechanicals is key to a happy unit.

 

[SciGuy]

Pull it, clean the blower wheel with a brush carefully because it's brittle from the heat, clean the plenum it's in and lubricate the bearings with light machine oil (3-1) works well. Re install it using the old gasket or a bead of Red RTV (allowing the RTV to cure before putting it back on (makes removing it later, much easier). make sure the venting pipe is clean as well.

Number one cause of stove / pellet boiler issues is dirty venting and tied up combustion blower issues followed by tied up distribution blower issues. Maintaining the mechanicals is key to a happy unit.

Just a few Harman oriented points that are important to be aware of. The blower wheel on a Harman is usually incredibly hard to pull if they've been mounted for several years. Many a cuss word has been uttered by those who try. Penetrating oil as well as heat may help but a Sawzall may end up seeing usage and that will lead to needing a new blower motor. Most people just clean them the best they can with the blower motor still mounted. If you do want to pull the blower motor the wheel must be removed first. The bearings on a Harman combustion blower are sealed so one is unlikely to get lube into them without undue complication. There is no gasket on a Harman combustion blower. I totally agree that dirty venting is a huge source of problems with pellet burners

 

[Mt Bob]

Turn power off,see if combustion blower spins freely, power back up and try again.Sometimes Harman boards do strange things if they have experienced a voltage surge.Also,there is a separate forum here,"The Boiler Room" that would probably be of more help to you.

 

[SidecarFlip]

Without getting into a lengthy dissertation about bearings. Don't matter if they are 'sealed' or not, it's a dust shield only and they will all accept lubricant, especially a light oil. Been oiling mine every spring when it gets taken apart and the 'sealed' bearings on mine (not a Harman) are going on 15 running years.

I prefer them over solid 660 CA impregnated bronze bearings that tend to get oval from runni9ng dry and then the only replacement avenue is replacing the motor unless you have the machine tools to turn new ones. and then fit them into the housings. I do and I have but common skate bearings are much easier to deal with,

Same applies to room air distribution blowers, dust sealed skate bearings as well as auger drives.

Skate bearings used in all stove drives are only dust shielded. Hermetically sealed bearings are way too costly for a stove drive. Don't matter who built the unit, they all share basically the same mechanical drive components, be it a 4000 buck unit or a 1000 buck unit.

Far as the combustion blower wheel, none of them will come off once they go through numerous heat and cool cycles, don't matter what brand of unit it is. Don't bother trying, you will fail or strip the fixing screw head. Just remove it, clean the plenum and brush the fanwheel off with a soft brush and above all resist the temptation to use even a putty knife because you'll break off the vanes, they have become very brittle from the heat of combustion.

Lack of combustion air (or draft if you want to call it that) is usually the direct result of a buildup of fly ash and it will also be present in the venting, especially in horizontal runs.

 

[Mt Bob]

Oh,another thread reminded me of this,if your external thermostat could be dirty,and the contacts are not closing.

 

[SciGuy]

Without getting into a lengthy dissertation about bearings. Don't matter if they are 'sealed' or not, it's a dust shield only and they will all accept lubricant, especially a light oil. Been oiling mine every spring when it gets taken apart and the 'sealed' bearings on mine (not a Harman) are going on 15 running years.

I prefer them over solid 660 CA impregnated bronze bearings that tend to get oval from runni9ng dry and then the only replacement avenue is replacing the motor unless you have the machine tools to turn new ones. and then fit them into the housings. I do and I have but common skate bearings are much easier to deal with,

Same applies to room air distribution blowers, dust sealed skate bearings as well as auger drives.

Skate bearings used in all stove drives are only dust shielded. Hermetically sealed bearings are way too costly for a stove drive. Don't matter who built the unit, they all share basically the same mechanical drive components, be it a 4000 buck unit or a 1000 buck unit.

Far as the combustion blower wheel, none of them will come off once they go through numerous heat and cool cycles, don't matter what brand of unit it is. Don't bother trying, you will fail or strip the fixing screw head. Just remove it, clean the plenum and brush the fanwheel off with a soft brush and above all resist the temptation to use even a putty knife because you'll break off the vanes, they have become very brittle from the heat of combustion.

Lack of combustion air (or draft if you want to call it that) is usually the direct result of a buildup of fly ash and it will also be present in the venting, especially in horizontal runs.

You’re right about removing the blower. I finally looked at an online manual and see that the boilers are vented as you said. Once again assuming made as a$$ out of me

 

[Mr._Graybeard]

The boiler was serviced in September and worked fine? I would assume a service tech would have cleaned the combustion fan and noticed if the bearings were seizing up.

There's a "power" light on the control panel. Is it lit?

 

[Former Farmer]

A couple lights do come on, but again nothing else. Not even a whir.

The boiler was serviced in September and worked fine? I would assume a service tech would have cleaned the combustion fan and noticed if the bearings were seizing up.

There's a "power" light on the control panel. Is it lit?

Which lights are lit? Do you have any voltage to the combustion blower?

 

[Mr._Graybeard]

Which lights are lit? Do you have any voltage to the combustion blower?

Yes, that's the next thing I'd do is some voltage checks with a test light. I'd also make absolutely sure that 6-amp fuse is good. Just looking at it isn't enough. Check for continuity.

 

[SidecarFlip]

The boiler was serviced in September and worked fine? I would assume a service tech would have cleaned the combustion fan and noticed if the bearings were seizing up.

There's a "power" light on the control panel. Is it lit?

Did you observe him doing that? Was it stated on the invoice and does it appear that he did by physically looking at the blower assembly?

 

[railfanron]

The blower assembly in that unit is easy to take out . I don't care what was done previously things happen rather quickly in an exhaust fan.
Here's what I would do.
1) take it out and clean it. Check to see if it spins freely.
2) If it spins freely then put it on a bench and put 120 volts to it and see if it spins up. If not new motor needed. If it does on to the next step.
3) put the unit in test mode and check to see if there is 120v at the blower connection wires. If there is and the blower spins up when testing it put it back together. It should work now. If there is no 120 volts on the wires then the control board is possibly bad.
4) If the blower is now running and the stove still doesn't feed pellets go on to the vacuum switch ( it will have a short piece of rubber hose and 2 wires connected to it. Unplug the stove and make a jumper for the 2 wires. Hook the jumper between the 2 wires and plug the unit in and try to start it. If it starts and feeds pellets then it needs a vacuum switch.

Ron
P.S. If you're not comfortable checking line voltage and/or making the jumper to run the motor on the bench call a repair man cause the life you save may be your own.