Harman XXV 'lazy flame' or BIG flame Issue

[wolfe2k]

The stove is plugged into a battery back up unit. I've tried plugging it directly in the outlet...no difference.
Thought briefly about getting the fan too but thought why not reuse what I have. I'll check the cold air inlet damper when I get home.

 

[wolfe2k]

Update:
- I got my new combustion motor today, looks like it will be a direct replacement with the one in the stove (no changes to wiring length or connectors).
- I took out the old blower motor. Tried and failed getting the old fan off the motor shaft. Just can't get the set screw loose. I did not order a new fan blade but it really doesn't matter yet. The fan HAS to come off the shaft because I need the mounting bracket that's located below it (new bracket is $37... um no). So, I've ordered a new fan blade just in case I wreck this one getting it off. I'll take the assy to work tomorrow and see if I can get it off (more tools available).
- Since I'm down, I removed the cold air line from the back of stove and verified the damper flap thingy flaps.
- I also disconnected the ESP connector from the control board and checked the resistance. Measured 1035 ohms. I was told it should be between 1000 and 1100 ohms at room temp.
- I'm running out of things to check and do. Hopefully I can get the combustion motor back together by the end of the week.

 

[rickwai]

I usually have to cut shaft off. set screw usually dont want to come loose. Also leaving air inlet pipe unhooked if you still have problems to rule out a blockage there

 

[wolfe2k]

Yeah, set screw won't come out. Gonna try to cut the shaft when I get home. What a friggin project.

 

[Ssyko]

Hacksaw blade and cut the motor shaft

 

[skirby1212]

Google “leaf blower trick” best way to clean out the stove and vent pipe

I have looked into that but tbought that only needs to be done once a season? Liner was brand new beginning of the season

 

[wolfe2k]

Replaced the combustion blower motor and fan about 3-4 days ago. First, stove is MUCH quieter so that's good.
My 'recollection' is that stove ran much steadier before. I have it connected to a wall mounted thermostat. I used to set it to 72 and I 'remember' it pretty much running right at 72 +/-1 most of the time. Flame wasn't too big or too small. Now it seems to have big temp swings from 70-71 for a low to 74-75 for a high. Stove flame is either really big or no flame. Everything seems to be working fine but it just seems different. My guess is this is how its supposed to work and what I saw before probably was not right. So I guess I'm done here
thanks for all the suggestions and help.

 

[SidecarFlip]

Admittedly, I don't know squat about Harman's other than they are pretty but a stove, pellet or wood or coal has to have 3 things to operate correctly, a supply of combustion air, a way to strip the heat from the stove body (which can be natural convection or forced air) and a means to exhaust the combustion air and burning by products into usually a chimney or approved exhaust vent system.

I'd say after 7 years, your combustion air motor is probably going south. They do wear out. They operate in a hostile enviroment (heat and dust) so they expire (slowly usually) as the bearings fail. I'd order a new one and replace that first off. I'd also order a spare auger (if Harman feeds via fuel auger) motor and a spare room air fan motor or complete assembly and keep the old ones, they are rebuildable ewith a little knowledge and time.

Nothing mechanical lasts forever. After 7 years, I'd say you had a good run but now it's time for some new parts. Just my opinion.

Black sooty pipes are real indicative of lack of combustion air or insufficient forced draft (on pellets). On corn, the opposite is true. On corn you will get black but not soot. The by products of burning corn is a dark ash.

 

[Oregun]

Replaced the combustion blower motor and fan about 3-4 days ago. First, stove is MUCH quieter so that's good.
My 'recollection' is that stove ran much steadier before. I have it connected to a wall mounted thermostat. I used to set it to 72 and I 'remember' it pretty much running right at 72 +/-1 most of the time. Flame wasn't too big or too small. Now it seems to have big temp swings from 70-71 for a low to 74-75 for a high. Stove flame is either really big or no flame. Everything seems to be working fine but it just seems different. My guess is this is how its supposed to work and what I saw before probably was not right. So I guess I'm done here
thanks for all the suggestions and help.

Yeah that is how my XXV behaves too, if the temperature outside is stable I'll just run it on stove mode instead of room temp mode.
Then it just chugs along with a small to medium flame.

 

[SidecarFlip]

Don't toss the old one, it is rebuildable. You will have to soak the setscrew that locks the combustion fan to the motor shaft with P'Blaster or a mixture of Acetone and ATF for a good while to get it to release but it's doable if you take your time and then the bearings on the armature shaft can be renewed and you get a working spare just in case. Being frugal (cheap), I don't throw any component away (except control boards and then only because I'm not an electronic whiz), I rebuild them all and keep them as spares.

 

[SciGuy]

Don't toss the old one, it is rebuildable. You will have to soak the setscrew that locks the combustion fan to the motor shaft with P'Blaster or a mixture of Acetone and ATF for a good while to get it to release but it's doable if you take your time and then the bearings on the armature shaft can be renewed and you get a working spare just in case. Being frugal (cheap), I don't throw any component away (except control boards and then only because I'm not an electronic whiz), I rebuild them all and keep them as spares.

On a Harman stove you need to cut the shaft of the blower to remove it from the stove if you are unable to get the impeller off. Not such a great spare at that point

 

[SidecarFlip]

That is too bad. I presume, like all other combustion fans, the setscrew locks on from the heat. Why I suggested PBlaster or acetone / atf and time to break it loose.

 

[SciGuy]

That is too bad. I presume, like all other combustion fans, the setscrew locks on from the heat. Why I suggested PBlaster or acetone / atf and time to break it loose.

It would sure be worth a try in the off season but not so much if it’s going to be -10*F tonight and the stove is your sole source of heat.

 

[SidecarFlip]

We tend to turn the units off in the spring, clean them out and forget about them until fall so issues that were brewing the winter before are also forgotten about. I'm guilty of that myself as well. How I wound up with a spare combustion blower, same scenario but I bought the entire assembly, not just the motor.

One word of caution on the combustion fans. They become somewhat fragile after use, that is, they get brittle so it's easy to snap the vanes off if you aren't real careful with them. Don't ask how I know...

 

[rickwai]

Admittedly, I don't know squat about Harman's other than they are pretty but a stove, pellet or wood or coal has to have 3 things to operate correctly, a supply of combustion air, a way to strip the heat from the stove body (which can be natural convection or forced air) and a means to exhaust the combustion air and burning by products into usually a chimney or approved exhaust vent system.

I'd say after 7 years, your combustion air motor is probably going south. They do wear out. They operate in a hostile enviroment (heat and dust) so they expire (slowly usually) as the bearings fail. I'd order a new one and replace that first off. I'd also order a spare auger (if Harman feeds via fuel auger) motor and a spare room air fan motor or complete assembly and keep the old ones, they are rebuildable ewith a little knowledge and time.

Nothing mechanical lasts forever. After 7 years, I'd say you had a good run but now it's time for some new parts. Just my opinion.

Black sooty pipes are real indicative of lack of combustion air or insufficient forced draft (on pellets). On corn, the opposite is true. On corn you will get black but not soot. The by products of burning corn is a dark ash.

On my St Croix burning corn The ash is basically black and dense but the color goes from brown down lower to snow white at the top. Its kinda crazy! You can rub the ash in your hand and it leaves nothing behind.

 

[rickwai]

I have not posted a pic directly from my phone before!

 

[SidecarFlip]

...and I refrain from doing that. Tap-A-Talk will blow up a picture to enormous size.

I think ash color depends on the strain burned. I'm burning Cruzer this year, but then I mix in pellets always. Keeps the clinkers to a minimum.

 

[rickwai]

Sorry for the picture blow up! Do you just sign into hearth on google on the iphone to post a picture? I have posted a pic before but I was sending it by email then posting off laptop. Kind of a pain

 

[SidecarFlip]

Sorry for the picture blow up! Do you just sign into hearth on google on the iphone to post a picture? I have posted a pic before but I was sending it by email then posting off laptop. Kind of a pain

Phone based browsers do that. You need to reduce the picture size as much as possible before sending it. Why I used Tap-a-Talk but quit using it.

 

[dougd]

How was problem resolved? BIG FLAME? Use anti seize on set screw when reassy fan blade they come right off. Get Soot Eater brush system for pellet stoves pipes.