Heat Pumps and Electric Heating - No AC Power to thermostat
Doityourself.com community forum was created to provide answers to all questions related to home improvement and home repair. Doityourself community can help you find information about how-to topics on small fixes to large remodeling projects. With comprehensive how-to content and expertly moderated community forums DoItYourself.com makes it easy to tackle even the most complex home improvement projects.View Full Version : No AC Power to thermostat
reed3325
11-14-04, 01:37 PM
I was replacing the original mechanical thermostat on my Carrier 2 stage heat pump system with a Hunter programmable unit. After installing, I was getting a "NO AC POWER" messsage and after reinstalling then excahnging for a new one, I keep getting the same message. I reinstalled the old mechanical one and nothing works. I carefully labeled the wires and followed the installation instructions but I failed to turn the power off to the system before the first install. Could I have fried my wiring somewhere?
Ed Imeduc
11-14-04, 01:48 PM
Could have for sure. Check out the transformer in the unit and see if you have 24V there on it.can try and jump R to G see if you get fan. That should tell us if you still have the 24 V. Dont like to use the program tstat on a heatpump. When you set them back the home cools down ,when it turns the heat back up it will kick in the strip heater to help so you dont save much that way.
ED ;)
ED ;)
jpmorgan12
06-04-06, 07:56 PM
Help (hopefully Ed still checks this forum),
The exact same thing happened to me. Tried to hook up the new Hunter Heat Pump thermostat w/o cutting off the power. Got a spark, then I realized I needed to cut off the breaker; then installed as instructed. Got a "No AC Power". Cut my losses, hooked up the old mechanical thermostat and same thing - - no power!! I'm sure it is hooked up properly.
Did my stupid mistake likely fry something? How expensive of a repair could I be looking at? Would an AC expert be the person to call for the repair, or an electrician.
Frustrated in North Carolina!!! Please help.
Thanks. :confused:
The exact same thing happened to me. Tried to hook up the new Hunter Heat Pump thermostat w/o cutting off the power. Got a spark, then I realized I needed to cut off the breaker; then installed as instructed. Got a "No AC Power". Cut my losses, hooked up the old mechanical thermostat and same thing - - no power!! I'm sure it is hooked up properly.
Did my stupid mistake likely fry something? How expensive of a repair could I be looking at? Would an AC expert be the person to call for the repair, or an electrician.
Frustrated in North Carolina!!! Please help.
Thanks. :confused:
Ed Imeduc
06-04-06, 10:04 PM
Check for 24V there. could be the transformer. Also lots of units have a small fuse in them for the transformer.
ED;)
ED;)
dweekman
01-18-07, 04:07 PM
reed,
I know it has been 5 years since you posted your message but do you remember what the problem was and how you fixed it???
I know it has been 5 years since you posted your message but do you remember what the problem was and how you fixed it???
All_Thumbs
02-16-08, 12:43 PM
I had this same issue yesterday on a Trane HP. I had moved the thermostat for a remodeling project and neglected to turn the power off first. The Trane was thankfully smart enough to have a 5 amp fuse. Only downside was that none of my vehicles use 5 amp fuses, so it looks like another trip to the store!
Good luck!
Good luck!