Need help with PF100

[exoilburner]

I am having an issue where the distribution blower won't stay on. Will run for a minute than shut off....New circuit board installed two weeks ago to fix an ignitor issue (always) on. Appreciate any thoughts and/or questions.

The distribution fan is controlled by the White Rogers fan control box which is located on the hot air duct 11 inches above the PF100. It rotates as the duct temperature rises and falls. If you twist it with your fingers it may mess up it's calibration. It sounds like the cam switches inside yours need to be adjusted. The procedure to adjust the cam switches is in the Harman Installation and Operating manual. This part is kind of cheap; I had to replace mine because one of the switches failed. Found the identical part on Amazon for nearly half the price that Harmon & the dealer were charging.

 

[bwep]

How is the air flow out of the heat registers in your living area. Can you feel good warm air flow out of all of them? If not check the cold air return filter on the PF100 and see if it is dirty or installed with the air flow arrow in the wrong direction. Maybe your the distribution blower is not moving enough air thru the hot & cold air plenums.
If there is a way to check the isolation damper in your plenum check it to be sure it is closing off the air flow to the oil furnace but not the PF100. If it is open to both the PF100 and the oil furnace, a portion of the hot air from the PF100 may be bypassing your living space and circulating around the oil furnace and the PF100.

Good advice there. I heat 2400sq ft and I never have a problem with the furnace keeping the house warm. I also run my furnace parallel with my propane furnace. Once i forgot to block the return between the two and it would draw back threw the propane furnace causing a weak supply of heat to the house. I also see you run your distribution fan on medium, you might want to try high, that works best for me.