Have HVAC Questions? Ask an HVAC Expert for Answers
Hi, I'm Tim and I'm an HVAC expert here to assist you with your questions. Please provide all information I request as it makes it more difficult to troubleshoot something when I'm not there onsite. Essentially, you become my eyes and ears. Thanks for the opportunity to help. At the end of our dialog, you will have a chance to rate my service, but please wait until we are finished and you're satisfied you have all the information you need. Please be patient as many times we work with several customers at once.
What is the make and FULL MODEL NUMBER of the furnace? What position do you have the fan switch at the thermostat?
That is your outdoor unit.
Which fan is running constantly, indoor or outdoor?
By the way, that last model number you gave me is for your COIL? See here.
That's your gas valve. See here. Still not the furnace model I need.
When this happens are you in heating mode or cooling?
Next time it happens, go down and check for a flash code in the lower door. The furnace may be going out on a flash code error.
On page 82 of this document, these are the error codes you will be looking for.
There will be a series of short flashes followed by a pause and then so many long flashes.
Should be a small window through which you can see these codes.
Sometimes on the Carrier and Bryant furnaces, you need to take the bottom panel off and then there will be a second panel with a small window.
This flash code will ONLY HAPPEN when furnace shuts down (burners go off) on an error code. It will not happen during normal operation.
Wait until the next time this happens and let me know. Question will remain open, so don't worry if it does not happen right away.
I have to step out for a bit, but will check back a bit later.
Did you have all the information you need here? Please let me know so that if you do, we can close question.
Is the fan running without the burners on for extended periods?
That is what I need to know. After the burners shut down, fan should run maybe a maximum of 2 minutes, then shut down.
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