Heating, Air Conditioning, Fridge, HVAC/Heil furnance


Heil furnance model NTC6100GFA1. Heats for while then blows cold air. If I shut off 10 min begins to heat
then blows cold air again

The furnace control board ought to have an LED.  The LED will flash error codes when it shuts down.  That is going to help you determine why the board is shutting the unit down.  I would suggest at the very least is to check for dirty air filter(s) or air flow restrictions.  Given the run time is almost appears to be over-heating.


Heating, Air Conditioning, Fridge, HVAC

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Craig HVAC Expert


I have been in the HVAC field for the past 18 years. I can help with most HVAC questions. I work on commerical buildings for the most part, and have yet to find anything I could not troubleshoot and repair, when repairable. I work on small 1 ton units to a 2500 ton chiller. Troubleshoot air flow, elect, and control problems. I attend regular classes to keep up with the latest and greatest.


I work on commerical sites, hospitals, gov't buildings. I can troubleshoot just about anything in the HVAC business.

5 years trade school, VFD training classes, Liebert factory training, some York and Trane factory training.

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