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BillyHvac
BillyHvac, Journeyman HVAC Tech
Category: HVAC
Satisfied Customers: 22472
Experience:  Endorsed for unlimited heating, cooling, oil burners, boilers, refrigeration, hydronics
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My furnace ignites, runs for a short time then burner shuts off

This answer was rated:

Furnace ignites and runs for a short time, then burner shuts off. No codes

If no codes then it is one of 2 things...

either the thermostat is turning power off to the W connection at circuit board..

Or the circuit board is bad.

A fault with the gas valve would result in a code.

To test...remove the thermostat and take the wire from R and the wire from W and twist together. If furnace runs without stopping replace thermostat.

If the furnace faults with blink code then it is bad circuit board.

Customer: replied 5 years ago.
same problem
Could you be more specific...

Do you mean with R and W jumped the furnace still faults and the light never blinks?
Customer: replied 5 years ago.
the ingniter still comes on ,ingnites furnace,but when ingniter ic cooling off the flame shut off this cycle repeats
Have you let it cyle through 3 times until it shuts itself down?

Have you cleaned the flame sense rod with steel wool?
Customer: replied 5 years ago.

Thanks! cleaned flame sense rod and furnace runs correct.

Excellent. Thanks for your patience.

BillyHvac, Journeyman HVAC Tech
Category: HVAC
Satisfied Customers: 22472
Experience: Endorsed for unlimited heating, cooling, oil burners, boilers, refrigeration, hydronics
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