Harman P38 blower problem

[nhhousewife]

Hello-

We had to change out the blower in the back of our pellet stove. It's running now, but we can't get the distribution blower to work for more than about 15 seconds. Suggestions?

 

[JDenyer236]

Which blower did you change out and why?

 

[nhhousewife]

Which blower did you change out and why?

We changed out the big one in the back because it was squealing that didn't stop after cleaning and oiling. It would squeal to a stop and then start again. Once it started doing that it would squeal with increasing frequency. At the end of heating season it was stopping about once a minute or more. It was scaring our young son and annoying the crap out of the adults!

 

[JDenyer236]

When you say the big blower in the back are you talking about the blower that circulates the room air or the exhaust blower?

 

[nhhousewife]

When you say the big blower in the back are you talking about the blower that circulates the room air or the exhaust blower?

the one that circulates the room air

 

[TheRambler]

The distribution blower is the one that circulates room air... I am confused. Can you try to explain a little more clearly which one you replaced and which one isnt working. The way it sounds to me is you replaced the distribution blower, but its still not working. Is this correct? If its workibg ibtermittantly i suspect 1 of 2 things, loose wire or a loose, disconnected, or cracked pressure/vacuum line. The vacuum line thing was the cause of my distribution blower problem causing it to run sporadically. There is a strong possibility one of these lines was knocked loose during the repair.

 

[nhhousewife]

The distribution blower is the one that circulates room air... I am confused. Can you try to explain a little more clearly which one you replaced and which one isnt working. The way it sounds to me is you replaced the distribution blower, but its still not working. Is this correct? If its workibg ibtermittantly i suspect 1 of 2 things, loose wire or a loose, disconnected, or cracked pressure/vacuum line. The vacuum line thing was the cause of my distribution blower problem causing it to run sporadically. There is a strong possibility one of these lines was knocked loose during the repair.

we replaced the big one that looks like a snail. It is working ok now. BUT the little fan that has the guard over it is now squealing

 

[JDenyer236]

Check your wires to and make sure all your connections are tight. Is your esp probe clean? A dirty esp can cause the symptoms that your having.

 

[TheRambler]

If its squealing, then your options are clean, lubricate, or replace.

 

[nhhousewife]

ESP probe? What and where are those?

 

[JDenyer236]

Ok your combustion blower is now squealing. Clean the combustion blower and if it continues to squeal then you're gonna have to replace it.

 

[TheRambler]

Exhaust sense probe, its right where the exhaust piping exits the unit, it looks like the insert inside of a ballpoint pen kinda with two wires on it

 

[Bioburner]

The exhaust-combustion fan. Can be a real bugger to replace as the fan in the exhaust path usually is froze or stuck permanently on the motor shaft. Most new installs require the cutting of the shaft to remove motor. Motor is about $100 available from Amazon and Ebay and will need a new fan too Online videos of cleaning Harman stoves usually point out the VERY important ESP that can be seen just a few inches inside the exhaust path after removing the fan cover in the rear of the ash bin.

 

[JDenyer236]

Anyway you can get us a pic of the fan that's making noise? That way we can be sure of which part it is.

 

[fmsm]

How old is the stove? How often is it cleaned? Who cleans it? When was it last cleaned? And last but not least, if you clean it what do you consider a proper cleaning, exhaust,etc.

 

[nhhousewife]

I'm not sure how old it is. It was here when we bought the house in 2010. The fan that was squealing was on the right looking at the back of the stove. Had the blower that blows the hot air around the room working yesterday, which was the one that wasn't working when we first started it. We toyed with it and were able to get it working. Today however, it didn't even come on for the test

 

[nhhousewife]

it's cleaned about once a month during heating season. We clean it, we have an ash vacuum and suck out everything we can, scrape with a scraper to get any flaking off, and run a chimney brush through the vent until it stops putting out fines. It was last cleaned this past week when we took it all apart to change out the blower

 

[TheRambler]

Do they spin freely by habd with no power on them, or do they have some resistance or rough spits when trying to spin them by hand?

 

[nhhousewife]

spin freely

 

[fmsm]

Describe your exhaust and your cleaning of it/frequency.

 

[JDenyer236]

Because these are variable speed motors then it's either the motor or the board. The board has the electronics that drive the motors.I replaced a perfectly good motor one because it ran terrible. Turns out the board wad bad.

 

[TheRambler]

I would pull all affected blowers, clean very thoroughly and use a light machine oil or lithium grease on the motor shaft. VERY light coating of oil or grease. Squealing is a mechanical swymptom, a bad control board wont cause a blower to squeal. If they operate most of the time but squeal then i would suspect they are dirty or need some light lubrication.

 

[JDenyer236]

I would pull all affected blowers, clean very thoroughly and use a light machine oil or lithium grease on the motor shaft. VERY light coating of oil or grease. Squealing is a mechanical swymptom, a bad control board wont cause a blower to squeal. If they operate most of the time but squeal then i would suspect they are dirty or need some light lubrication.

This is very true however the motor I replaced that turned out to be the board made a terrible rumbling noise. although squealing definitely sounds like a bearing. Try oiling it first and if it runs fine then order a replacement.

 

[Harman Lover 007]

Too many confusing posts by the OP here. nhhousewife, you have replaced the distribution blower (the one you say looks like a snail) correct? Does that fan now work properly?
Secondly, the fan/motor you say squeals, (the one with the cage and much smaller than the one you replaced) does that one work in "test" mode? Does that one spin freely as well?