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 Phil Your Own Question
Phil
Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 5648
Experience:  Retired HVAC/ Electrical & Boiler contractor. Industrial
23932409
Type Your HVAC Question Here...
Phil is online now
A new question is answered every 9 seconds

Ran new tstat wire had lights on board. Turned tstat on

Customer Question

Ran new tstat wire had lights on board. Turned tstat on nothing. Now no lights unhook red wire still nothing tformer still good fuse good
Submitted: 1 year ago.
Category: HVAC
Expert:  BillyHvac replied 1 year ago.
is fuse blown
Customer: replied 1 year ago.
No
Expert:  BillyHvac replied 1 year ago.
Is transformer still ok?
Customer: replied 1 year ago.
Could it be wire to outside unit
Expert:  BillyHvac replied 1 year ago.
That is commonly where the damage is...the outdoor wire or contactor...
Customer: replied 1 year ago.
Transformer bench test ok
Expert:  BillyHvac replied 1 year ago.
If transformer is good and fuse is good but no light on board or thermostat power...it would be a bad board...
Customer: replied 1 year ago.
Unhooked the outside wire. No 24 volt on board
Expert:  BillyHvac replied 1 year ago.
no power R to C?
Customer: replied 1 year ago.
I had lights on board until I turned on tstat. Tstat works other unit in house
Customer: replied 1 year ago.
I'll check
Expert:  BillyHvac replied 1 year ago.
did it blow right away...or after turning to cool
Customer: replied 1 year ago.
Right away. Nothing r to c
Expert:  BillyHvac replied 1 year ago.
if fuse is still good and transformer is good then board is bad
Customer: replied 1 year ago.
OK thanks
Expert:  BillyHvac replied 1 year ago.
let me know if any other info pops up.
Customer: replied 1 year ago.
Ok
Customer: replied 1 year ago.
The same problem with the new board. I do however have 25 volts on the neutral with the door switch open

Related HVAC Questions