Armstrong Inducer cycles on and off continuously

[areizman]

I have an Armstrong Air Ease furnace IV from circa 2000.

I recently had the smart valve replaced and have a problem with the air inducer fan that has puzzled two different repairmen.

When the thermostat is not calling for heat or is turned off the air inducer fan will cycle on off continuously. This goes on for hours or or runs in spurts.

When heat is required the inducer and furnace runs properly. I had the air tube from the pressure switch blown out, changed the thermostat, and just had the circuit board replaced.

I just changed the filter and found the sound insulation around the filter opening has come loose. I pulled that out and am awaiting to see if that has anything to do with my problem.

Any other ideas out there? Lots of solutions for the furnace not coming on at all but I cannot find this problem. Please help. Thanks in advance,
AL R..

 

[HVAC Phil]

I have an Armstrong Air Ease furnace IV from circa 2000.

I recently had the smart valve replaced and have a problem with the air inducer fan that has puzzled two different repairmen.

When the thermostat is not calling for heat or is turned off the air inducer fan will cycle on off continuously. This goes on for hours or or runs in spurts.

When heat is required the inducer and furnace runs properly. I had the air tube from the pressure switch blown out, changed the thermostat, and just had the circuit board replaced.

I just changed the filter and found the sound insulation around the filter opening has come loose. I pulled that out and am awaiting to see if that has anything to do with my problem.

Any other ideas out there? Lots of solutions for the furnace not coming on at all but I cannot find this problem. Please help. Thanks in advance,
AL R..

My guess would be a bad control module or tstat. Does it still do it with tstat wires disconnected from control board?

 

[areizman]

I changed out the thermostat and the control board and still had the problem.
With the thermostat removed and nothing connected to the wires the inducer was silent. But I installed a new thermostat and still had the problem which should eliminate the board and thermostat as the culprits. So far since I pulled out the loose sound insulation and changed the filter the inducer and furnace are working normally. I'll post an update if the situation changes.

 

[rickairmedic]

The only thing that pops into my head with the board and t stat already replaced is a short somewhere possibly in the t stat wires .


Rick