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HVAC Guru
HVAC Guru, HVAC TECH
Category: HVAC
Satisfied Customers: 15084
Experience:  15yrs in the HVAC industry with certificates and degrees.
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Tried to swap out thermostat. New Nest thermostat didn't

Customer Question

Customer: ***** *****. Tried to swap out thermostat. New Nest thermostat didn't fire up, so replaced original thermostat, which displayed briefly, then no display after that. Now furnace is indicating polarity reversed, although no wiring was touched. Just thermostat wires.
JA: Thanks. Can you give me any more details about your issue?
Customer: Other than what I just provided?
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Customer: okay
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Submitted: 1 year ago.
Category: HVAC
Expert:  HVAC Guru replied 1 year ago.

Hello and thanks for using this service, if you have been waiting do not worry or get upset I am just one of the techs on here and I try to get to as many customers as I can and I just picked up your question now. Please give me time to respond sometimes I get your replies late so there may be a delay in my response.

Shut the power off to the unit for 30 seconds then try it and check the low voltage fuse on the unit, if it still displays that code the board is bad, not much else causes that code other than a bad board something likely happened to it when you were switching the thermostat wiring.

We are on the honor system for our time, all I ask is please rate my service using the STAR RATING LINK on your page before you leave. If you are not happy with the service please let me know before leaving a negative rating. This is the only way I am paid or credited through the site for my time. This will also allow you to get directly back to me for FREE follow up questions and tips are greatly appreciated! Thanks