How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask airheatman Your Own Question
airheatman, HVAC Technician
Category: HVAC
Satisfied Customers: 8259
Experience:  Furnace, A/C and heat pump specialist.
Type Your HVAC Question Here...
airheatman is online now
A new question is answered every 9 seconds

I have the Signature P374-1800 model thermostat. Last

Customer Question

hello, i have the Signature P374-1800 model thermostat. Last night the AC was not cooling down the unit, so I went to the electric power box and shut the power off for a minute and turned it back on. The problem is that the thermostat won't turn back on. The screen is blank. Can someone please help?
Submitted: 2 years ago.
Category: HVAC
Expert:  airheatman replied 2 years ago.
Hello. My name is ***** ***** I'll do my best to help. Let's get started and see what we can do.Do you have a multi meter so we can see if we are getting 24 volts to R and C terminals at thermostat?
Customer: replied 2 years ago.
Hi, multi meter>
Customer: replied 2 years ago.
Multi meter?
Expert:  airheatman replied 2 years ago.
Test meter. If you don't have one you can get one at Walmart for about 15 bucks. Then.Lets set to lowest setting above 24vac and put one lead on R and one lead on C and verify 24 volts.See link below:
Customer: replied 2 years ago.
There is power going to every light, appliance, electrical outlet. I highly doubt that the problem is stemming from lack of electrical power from the electrical source.
Expert:  airheatman replied 2 years ago.
The first step in troubleshooting your thermostat is to see if the indoor unit is providing 24 volts to the thermostat.
Lights,appliances,electrical outlets and such have nothing to do with this.
You can even have power going to the furnace, but if transformer is bad, a small auto type fuse on furnace control board or a bad connection between furnace and thermostat could be preventing the thermostat from getting power.PLease let me know if you wish to troubleshoot.

Related HVAC Questions