Harman p38/oak

[bayfeet]

I have a Harman p38, that was installed new this fall, with outside air kit. I notice/hear the air coming in from outside air vent creates a cavitating sound, and movement. The outside air is a straight shot to the stove with flexible pipe connected to the vent and stove. If I'm outside I can sometimes hair this vibrating sound and inside it can be distracting. Is there a way to adjust this flow so it stops this? I usually put the burn pot cleaner tool on top or against the air pipe to reduce the sound/vibration. I know there is a trim pot adjustment for this stove that is set at the factory, and usually checked by the installer with a draft meter of some type. Anyone have this problem? Any fixes? Thanks, Ed

 

[MCPO]

I have a Harman p38, that was installed new this fall, with outside air kit. I notice/hear the air coming in from outside air vent creates a cavitating sound, and movement. The outside air is a straight shot to the stove with flexible pipe connected to the vent and stove. If I'm outside I can sometimes hair this vibrating sound and inside it can be distracting. Is there a way to adjust this flow so it stops this? I usually put the burn pot cleaner tool on top or against the air pipe to reduce the sound/vibration. I know there is a trim pot adjustment for this stove that is set at the factory, and usually checked by the installer with a draft meter of some type. Anyone have this problem? Any fixes? Thanks, Ed

What size pipe? If it`s vibrating it could be the air flow is either restricted or the combustion fan is running too high thus drawing in more air than it needs.
Mine is a 26 ft run but I used 4" and I can hear the air being sucked in. I was surprised at the velocity/amount of combustion air it uses.

 

[bayfeet]

The inside diameter is 2 3/8. It is flex pipe, short run maybe about 20 inches. Ed

 

[MCPO]

The inside diameter is 2 3/8. It is flex pipe, short run maybe about 20 inches. Ed

Wish I could help , being it`s new you might want to have someone (qualified) take a draft reading , however if you are mechanically talented you could try adjusting the low draft (page 18 in your manual for instructions) to see if it makes a difference.

 

[bungalobob]

I have the P68 with outside air kit installed. I have no noise that can be heard from the air supply. I wrapped the flex pipe last week with insulation to prevent some of the moisture that was forming on the really cold days. While I had it off I took a flashlight and checked where it actually went inside. There is a metal flapper on the stove to prevent air from going the other way, maybe you should check that and make sure it moves freely and is not obstructed in any way. The flex hose is just pushed into place, easy enough to check. Just don't burn yourself back there. Also, while the hose is off check to make sure nothing is inside of that as well and the connection through the wall. You never know. Good luck and happy burning.

 

[Wet1]

I can hear the same on mine when I'm outside at the OAK, I've never noticed it inside.