Harman P38 - more tinkering or replace it?

[Northbc]

Hi all - I've enjoyed reading this forum for years but just recently joined. I have owned a Harman P38 for the last 7 years and it has provided reliable heat. We like the convenience and it has needed very little maintenance even though it is about 20 years old.

However after a few years of operation we are getting tired of a) the noise, and b) the smoky basement. I have attempted to fix these issues every year but no success.

The main noise culprit is blower fan. I've disassembled, cleaned, and lubed but it made no difference that I could hear. Stove is in TV room and the constant whirring is bothersome.

Smoke - the basement often gets a smoky smell, maybe due to a lazy burn? Cleaning sometimes makes a difference and sometimes not. I've sealed every crack I can find around the nipple and basement wall/rim joist but it still happens fairly regularly. No luck finding it with a flashlight either.

Interested to hear your thoughts if I keep on troubleshooting or look at replacing. From what I've read here I may not be able to fix the noise issue. And I really have no idea what to do with the smoky smell. Are the new stoves advertised as 'noiseless' or 'very quiet' able to produce as much heat as this one?

Thanks in advance for your thoughts. We really do like the wood heat (it's secondary heat to our gas furnace) but we are using it less now due to the issues here.y

Cheers

 

[Lake Girl]

Smoke - the basement often gets a smoky smell, maybe due to a lazy burn? Cleaning sometimes makes a difference and sometimes not. I've sealed every crack I can find around the nipple and basement wall/rim joist but it still happens fairly regularly. No luck finding it with a flashlight either.

How fresh are the gaskets (door and/or window)? Do you have an OAK hooked up? Have you ever tested the draft pressure? page 18 of the manual http://downloads.hearthnhome.com/installManuals/PP38.pdf

Some of the fans can be revived by replacement of bearings. A new blower is a fairly small investment in the scheme of things for a quieter fan If you go with new, you could replace the bearings on the original for a back-up...

Keep us posted with your choices and results!

 

[Northbc]

How fresh are the gaskets (door and/or window)? Do you have an OAK hooked up? Have you ever tested the draft pressure? page 18 of the manual http://downloads.hearthnhome.com/installManuals/PP38.pdf

Some of the fans can be revived by replacement of bearings. A new blower is a fairly small investment in the scheme of things for a quieter fan If you go with new, you could replace the bearings on the original for a back-up...

Keep us posted with your choices and results!

I installed outside air intake 2 years ago but negligible difference. Never have touched door gasket but it looks good based on inspection. Thanks for your ideas! I will pursue draft testing and price out fan bearings. Cheers

 

[Lake Girl]

After 7 years (or longer since you said it was 20 years old), you should at least change out the door gasket. The grey/black kits are impregnated with graphite and purportedly hold up better.

 

[TStark]

The fan is likely bronze bushings and not replaceable.

One can dramatically reduce the fan noise, I found over the years.

First you may want to start with a new fan. That said, mine is 21 years old. Get oil on the motor's bushings. if that has never happened, it may be best to start new.

Then remove the impeller and evenly smear a thin film of rtv (I used copper gasket rtv) on the inside disk of the cage fan itself. Its benign, and entirely dampens the ringing that occurs with the cage blower impeller.

Now the removable ring surround you unscrewed to get the impeller out, reinstall that with a smear of rtv to suppress metal-metal noise.

Then, add rtv to the stamped-steel and spot welded housing on each outside seam. this suppresses the units buzzing and rattles that develop with incompletely welded metal joints.

Then mount the blower to the stove with gaskets made with 1/8" manniglas or equivalent, and using neoprene-backed washers. Quiet.


That smoke smell can be elusive. I just had a bout of that and removed, cleaned and resealed the stove-pipe interface adapter, with success. Its was real hard to detect the source.

 

[Lake Girl]

Is that copper gasket rtv easy to remove if you have to work on the fan again? Link would be helpful

 

[TStark]

Oh yes! if fact just took the ring off last week to remove the cage for a thorough cleaning. Just slipped a putty knife under the ring and worked it around with little effort. Afterward reassembled dry, as the rtv remained on the surfaces.
I think the product is less critical, as these surfaces stay very cool with so much room air moving through it. I think most any RTV gasket make would work, I just had the hitemp copper remaining from my exhaust reseal project.

I only chose to put the rtv on the motor side of the cage impeller's disk, so it was less prone to collect dust. I used the Permatex product

Tap on the fan or impeller when you are through, and you will hear more a thunk than a ring or buzz, and that should translate to quieter operation.

 

[gfreek]

The door gaskets should be checked doing the "dollar bill test".. Combustion blower ever been replaced ?

 

[Northbc]

Hi all - thanks for the helpful suggestions. I am second owner and as far as I know it's on all original parts. I routinely clean it, and added outside air intake. I also put foil tape on all vent gaskets, but no real change to smoke smells yet. We notice the smoke smell mainly in the 'other' rooms of the basement - my thought is that smoke is travelling above drop ceiling? Regardless I will inspect the door gaskets next and price out a blower fan.