Heating, Air Conditioning, Fridge, HVAC/finiky furnace


i have a TEMPSTAR gas furnace model #NUGI075DF03. For the last couple of winters it has been working very sporadically. When it receives a signal from thermostat to kick in, the pilot light comes on for may be 5 seconds but burners don't, then pilot goes out. After few cycles the burners eventually come on and house gets heated to desired temp. There are times when burners come on at first attempt but that's very random. The status LED indicates "Retry delay- third failure to light on same call for heat , trial for ignition after 5 mins delay" when that happens. When burners come on , the LED indicates Normal operation. Lst couple of years it has always came on eventually, but there's time in the winter when the temp dips real low since furnace needs 5 minutes waiting period to repeat 3 attempts to light up burners.
Your advice is much appreciated

I would guess your units needs a little bit of TLC.  The burners and flame sensor ought to be taken out and cleaned.  The chamber needs to be checked for any holes.  It might even be worth while to replace the flame sensor now before you really need it.


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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