Heating, Air Conditioning, Fridge, HVAC/HVAC gas furnace


My Trane XV80 gas furnace often fails to ignite when the thermostat calls for heat.  The diagnostic light then flashes three times, the code for pressure switch error.  I have installed a new pressure switch, but the problem continues.  Would changing the filters help?  Any suggestions?  Thank you.

The combustion air in and the vent exhaust out need the proper amount of air passing through to activate the pressure switch,
I don't know what or where they come from or exhaust to but any type restriction can cause the problem?
Changing the filters won't solve the problem.
to many turns and to much length on the exhaust, wind, back draft, etc.

Heating, Air Conditioning, Fridge, HVAC

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Jim Barnhart


Fifty + years conditioning the air.


Answer questions about , residential and commercial. Answer questions about sheet metal fabrication. Fifty years plus experience. No answers for oil equipment, No answers for kitchen appliances, No answers for laundry appliances, I don't specialize in one particular area of the HVAC area, I'm more of a General Practitioner, Limited in refrigeration/

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