Harman XXV 'lazy flame' or BIG flame Issue

[wolfe2k]

Stove has been installed for 7 years, working fine. Did my normal cleaning like I've done for 7 years. Only difference is I cleaned out the fines box too. When I started back up I get fire filling the entire chamber, wrapping around the sides and even going down below the burn pot. Read the forum, checked, rechecked the fines box cover several times. Highly unlikely I put it on wrong every time. Door gasket looked like it might have a leak so replaced the door gasket too. Checked the cover for the burn pot several times. Made sure the distribution motor and combustion motor were 'spinning'. Removed the ESP and it was pitch black. I just cleaned this (for the first time) about 2-3 weeks ago and at that time it wasn't even close to this dirty. I have direct venting, cleaned out the vent on the outside.
Cleaned the stove again just to cover all the bases. In the past, I'd only get smoke during ignition and then hardly any smoke during operation. Now when it runs its more like a campfire. Fairly continuous smoke. The stove just feels very hot, which I guess is expected since the flames are HUGE. The only time it dies down is when it reaches setpoint (I have it wired for a thermostat), and even that takes a while. It dies all the way down until it gets below setpoint again and then the big lazy flames come back.
I don't have a way of checking the draft but seems unlikely since its been running for 7 years.
I did notice the combustion motor seemed very hot to the touch but not sure what is normal. Not really sure what the next step should be. New combustion motor? New ESP? Getting no where at the moment. I posted a video since pictures weren't really showing the issue.
thanks

 

[Ssyko]

if your combustion blower motor (just the motor) is hot enough you can't hold your hand on it i would suggest it be replaced. but it is odd that it doesn't shut itself down with its thermal circuit built in, or maybe it is? do you know if it continues to run?

 

[wolfe2k]

I had touched it after the stove was off for a while and it was quite warm, like top of the stove warm. I'm pretty sure it runs continuously, I believe that is the motor noise I hear all the time.

 

[Oregun]

If you took off the fan blade on the combustion blower to clean it check that the set screw is on the flat surface of the shaft and tight.

 

[Dataman]

When's last time chimney was cleaned? Sound like it's suffering.

 

[SciGuy]

Stove has been installed for 7 years, working fine. Did my normal cleaning like I've done for 7 years. Only difference is I cleaned out the fines box too. When I started back up I get fire filling the entire chamber, wrapping around the sides and even going down below the burn pot. Read the forum, checked, rechecked the fines box cover several times. Highly unlikely I put it on wrong every time.

It’s incredibly easy to mess up closing the fines cover especially if you’ve not done one several times and developed a knack for how it feels when properly done. There’s a slot in the cover that must fit over a tab at the top of the fines box. Once you’ve cleaned enough of these you’ll get a feel for doing this by “brail”. I find it helps to unscrew the wing nut a good long ways so I can tilt the bottom of the cover out a bit to help fit the tab into the slot.

If you still have a lazy flame check one more time.

Hugh

 

[rickwai]

Also check your flapper on the inlet over kinda behind the circuit board. make sure it is free swinging.

 

[wolfe2k]

I am currently running the stove in 'stove temp' mode at 1. The flame seems way too big and lazy for being at level 1 but at least I can run the stove. I can smell a slight hint of smoke but have looked all over the stove with a flashlight and don't see any smoke.
I ordered a new combustion blower motor since the one I have seems to be running very hot. I am doubtful it will fix the problem but probably needs to be replaced any ways.
I checked the fines box again. This seems like the logical problem since its the only thing I did differently when I cleaned the stove. I even took off the wing nut so I could see if the notch in the cover was coming all the way down to the threaded rod. Doesn't come all the way but close. The slot at the top is over the tab. The stove is at a 45 in the corner so there's not a lot of room to get behind the stove but I'm fairly confident it's on correct.
Any ideas how you would clean out the exhaust pipe (see pic)? It seems pretty rigid so if I disconnected it from the stove I'm not sure it would move anywhere.

 

[Ssyko]

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

 

[Dataman]

You should have had Cleanout Tee. https://www.acehardware.com/departm...ROP2W2xiDTfGa0KyJiBoCI3sQAvD_BwE&gclsrc=aw.ds

 

[wolfe2k]

Will try the leaf blower trick!
thanks

 

[SciGuy]

Will try the leaf blower trick!
thanks

Last year I purchased a P38 from a fellow that admitted he hadn't really cleaned his vent pipe in ~ 7 years. When we disassembled the pipe we found that it was very occluded from all those years of accumulation. I'm not sure how well it was burning in the end but have a hard time imagining it ran well. I bet you'll make an excellent black cloud using the the leaf blower trick. I'd want to do some brushing too intermixed with the vacuum of the leaf blower.

Hugh

 

[wolfe2k]

I need to get an adapter for my leaf blower (4" to 3") in order to fit my pipe. Before I do the LBT, does any one know for sure if I need to disconnect the vacuum line for my Harman XXV first? 1)I'm not exactly sure where this is, possibly just above the combustion blower? and 2) I'm pretty sure it may be nearly impossible to get at.

As a side note:
As I was cleaning out the combustion blower motor area, I noticed it 'may' have been easy to not totally seal the motor in the chamber. It uses 2 wing nuts and one long extension rod and nut. I really only paid attention to the wing nuts. When I was installing I noticed the motor wasn't sitting right (small gap on the seal) and finally noticed the nut on the bottom rod was behind the motor flange. Any ways, I don't think this was my problem since I didn't remove the motor when the problem first started, but it is something to check for 'if' you do remove it.

 

[Ssyko]

Just open the main door to let air go through.

 

[wolfe2k]

Update:

1. Cleaned inside of stove again, including area beneath the burn pot.
2. Vacuumed out inside rear two panels, everything I could reach.
3. Brushed and vacuumed distribution fan blades.
4. Brushed and vacuumed combustion blower/fan then reinstalled verifying tight fit.
5. Reseated the fines cover again.
6. Cleaned ESP again.
7. Replaced door rope seal.
8. Did the leaf blower trick.

Stove set to Room Temp mode via a thermostat. Set to 72 deg, stove started and looked fairly normal for a few minutes but then the HUGE flames came back. The stove acts like its trying to get to temp all at once. Just feels like its burning WAY too hot. You can smell smoke so I checked with a flashlight behind the stove.....the exhaust pipe for the OAK (3" pipe) was smoking in sections, almost like the thermal seal tape adhesive was burning...that's what it looked like. The pipe is very hot, even after just a few minutes of the stove running. Once the stove reached setpoint, the flame slowly dies down, looks fairly normal and almost goes out until setpoint is reached again and the big flames come right back. Not an efficient way of operator a stove.
At this point I'm stuck. What about the ESP? Would that go bad? Why would the stove run so friggin hot?
How does it use and regulate the cold air coming in? Could there be a damper stuck open/closed?
thanks

 

[Oregun]

My XXV will start out like that if it takes too long to ignite and the burn pot overfills. But after a few minutes
it burns down and burns normally.

 

[miteclipse]

Video shows a normal startup sequence. Remember that your cold stove has to warm up to reach the desired temperature setting. It may go through this a few times before becoming more steady. Regarding the smoke smell, looks like you have to reseal the pipe coming from the exhaust. High temperature silicone tape can be used as well as it is much easier to temove than the foil. I do believe that most pipe manufacturer s require high temp sealant for the exhaust adapter/connection.

 

[Ssyko]

the exhaust pipe for the OAK (3" pipe) was smoking in sections, almost like the thermal seal tape adhesive was burning...that's what it looked like. The pipe is very hot, even after just a few minutes of the stove running

Did i read your statement right that the OAK is HOT? No way should that get hot! Has the combustion motor been replaced?

 

[wolfe2k]

I've had the stove for 7 years and it has never started like that. I let it run for about 1/2hr and as I mentioned, it just 'feels' like its running hot, lots of crackling sounds. It dies down to nothing when it reaches temp and then goes right back to a big flame when it drops below temp. Our cats used to sleep on top of the stove while it was running. There's no way they could do it now, even the top surface around the hopper is hot to the touch (I wouldn't leave my hand there).
Sorry to confuse about the OAK. No, the cold air line (smaller 2"?) is cold, it's the 3" exhaust pipe that is literally smoking hot.
Combustion motor is on its way, should have it replaced by this weekend. For now I'm keeping the stove off. Will update when I replace the motor.
FYI, the LBT worked great. At least I know the exhaust pipe is clear. I kept the door open just a crack when I did it.

 

[rickwai]

Is the inlet air flapper swinging free? It is right at the connector where your OAK hooks up to the back of the stove

 

[wolfe2k]

The cold air hose connects to the back of the stove in the location below. Are you saying to remove the hose and check to see if the flapper swings freely behind the connection?

 

[johneh]

Question. You have said nothing about the convection blower
Does it come on ? (blow hot air)

 

[wolfe2k]

I assume that's the distribution blower? Yes, I can see it spinning in the back and it blows hot air. If I turn the stove to high the blower increases and blows more.

 

[ABusWrench]

I've read this over twice. So I'll ask, is the stove on a surge protector?
I second, check intake flapper AND the rest of the oak for a restriction.
I can hear my intake flap moving as the stove lights.
What does it do when you open the door when it's running?
It should suck/hold the door closed when running.
Sure sounds like it's plugged/blocked or leaking somewhere.
I'm not familiar with the xxv, does it have an ash pan door?
Just throwing things out there.

 

[nayslayer]

I have a XXV as well and just this past fall i replaced the combustion motor. It's much more quiet and burning a little better. I have had my Stove for 8 years now. I'm no expert, but either the combustion fan, or air isn't getting in, or out. Sorry not much help. Good luck. Oh, i would have gotten new fan for blower too.