Gas and Oil Home Heating Furnaces - Furnace shuts off

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lewap
03-21-08, 10:13 AM
Hello,
I have a 8-years old "Concord" 90% Eff. furnace; since some time it's been acting up by doing the following:
when a Tstat calls for a heat, I can hear the burners igniting
but only for a couple of seconds, after that it SHUTS OFF, just like it's reached desired temperature; then again same cycle - burners ignite, and shut off after short period of time;
the LED light on the Valve blinks 6 times (system lockout);
after I turn off the Tstat and the furnace (switch on the wall) the LED light seems to reset and goes from Bright to Dim, which (according to the label) indicates normal operation. I changed Tstat 3 times, but same thing.
I had gas company to check for leaks - all OK.
When I keep Tstat and furnace off for a while, after turning it back on, it works again; recently it even lasted 3 days, but doing it again today.
I will appreciate any suggestion,
thanks,
L.


mattison
03-21-08, 10:37 AM
If you look into the burner section "with the furnace off" there should be a rod extending into the burner area "usually on the left side". Clean that good with a scotch brite pad and see if the furnace works good afterwards.

That's the flame sensor and sounds like your problem.

lewap
03-21-08, 01:40 PM
If you look into the burner section "with the furnace off" there should be a rod extending into the burner area "usually on the left side". Clean that good with a scotch brite pad and see if the furnace works good afterwards.

That's the flame sensor and sounds like your problem.

thank you very much for your quick and helpful reply;
that was IT, the flame sensor, i cleaned it and the furnace is working now;
thanks again!!!
L.