Harman P68 distribution blower motor wont kick into high

[DanT]

Hey guys I have a Harman P68 that for some reason the distribution blower motor will not run in high. Normal settings are Room temp in High @ around 72. Feed rate @ 4. It doesn't matter what I do it the fan will not run balls to the wall. Room remp cranked or stove temp cranked I just cant get it. I took the stove completely apart last night and cleaned everything. ESP, fans, blew everything out with air till the old lady bitching I was destroying the house. I brought the fan to work today, hooked up a power cord to it, plugged it to the wall and blows like hell. Anyone have any ideas at all?

 

[tsmith]

Maybe your potentiometer is bad. could try cleaning it or replacing it. See this link. https://www.hearth.com/talk/threads/accentra-controls.147072/

 

[Kennyz]

Does your stove have a high low switch? On my Accentra there is a switch on the main frame side when you open the control panel, up is high down is low, it limits the distribution blower max speed.

 

[DanT]

I have a turn nob for room temp L-H that adjusts it. No matter where its at it runs in low speed even maxed out.

 

[tsmith]

I have a turn nob for room temp L-H that adjusts it. No matter where its at it runs in low speed even maxed out.

That is why I think maybe the Pot switch is bad or dirty on your room temp knob. If they get dirty or go bad they wont read the adjustment when you turn them to different settings.

 

[Harman Lover 007]

Agree with the above. Sounds like a bad potentiometer. Does it blow on high on Stove Temp mode? I've had some luck cleaning them with the computer keyboard cleaner. You need to clean right where the white shaft goes into the square blue pot.

 

[DanT]

I have ran it in both stove temp mode and room temp mode. Now the fan wont even run at all. Tested volts going to the fan on it this afternoon and it has 110 volts going to fan out of the blue wire and 10 volts coming out of the white wire or vice versa. Cant remember which had 110 volts. Cut a extension cord and hooked it up to the blower and it runs good but when its plugged to the stove I have nothing at all anymore. I pulled it out again to double check the fan still runs being plugged into the wall and same results. Runs like an animal. Took the board out and brought it to work and going to have my Instrumental guy test the board tomorrow for obvious faults.