thermostat heat pump help needed


  #1  
Old 11-22-08, 09:39 AM
L
Member
Thread Starter
Join Date: Nov 2008
Location: Usa
Posts: 3
Received 0 Votes on 0 Posts
thermostat heat pump help needed

Hi,
today I began to get cold and noticed that my thermostat was dead. I have 2 carrier heat pumps in my house and the downstairs t-stat is blank. No batteries etc. I've opened it up and checked with my voltage meter and have gotten nothing for power. Red to Green, Red to White nothing comes on, can't reset it etc. So I'm reading that it may be a fuse on my transformer. The dowstairs unit is in the crawlspace and I really don't know where to begin to look for the transformer. Do I take the panels off the unit and start looking for the part with 120 coming in and the 24v going out? If so how do I test it and do I shut the power off at the house main before using the voltage meter on anything? How will I know its the transformer or just the fuse and will the fuse be on the transformer? Thanks to anyone who can help. ~Lisa
 
  #2  
Old 11-22-08, 09:59 AM
Jarredsdad's Avatar
Member
Join Date: Oct 2002
Location: Troy, VA
Posts: 1,527
Received 0 Votes on 0 Posts
Check the breaker in the house breaker panel first.

Then check for a fused disconnect at the unit.

Then check for 220 VOLTS being supplied to the indoor unit.

If these tests prove good, then you can start to worry about a transformer or blown low voltage fuse.

Model and Serial Number?
 
  #3  
Old 11-22-08, 03:42 PM
L
Member
Thread Starter
Join Date: Nov 2008
Location: Usa
Posts: 3
Received 0 Votes on 0 Posts
Here's whats up

Ok, I've opened up the box that holds 2- 45 amp buss fuses. One was blown. Just as a test, I put this fuse set into the upstairs furnace and it wouldn't work, replaced it with its own and it worked. I've replaced the bad fuse and still nothing happens. There is not tripped breaker and I've reset the breaker. There is no reset switch out on the fan unit anywhere either. The only think I haven't checked yet is to see if there is a reset switch by the blower. I did try to take a meter reading from the box with the 2- 45 amp buss fuses are and I got nothing from my little multimeter. I'm not getting power somewhere and I don't know how to test to see if the breaker is bad. Again, Its never tripped. I'm confused and my digital thermostat is still blank. Any further advise for this carrier heat pump. I'll have to look for the model number.
 
  #4  
Old 11-22-08, 03:45 PM
L
Member
Thread Starter
Join Date: Nov 2008
Location: Usa
Posts: 3
Received 0 Votes on 0 Posts
also

I did replace the little 5 amp fuse with an extra sitting in the box. Still nothing. I used the multimeter to test where that fuse goes and got nothing on that reading either. Maybe I'm not testing correctly?
 
  #5  
Old 11-23-08, 05:48 AM
Jarredsdad's Avatar
Member
Join Date: Oct 2002
Location: Troy, VA
Posts: 1,527
Received 0 Votes on 0 Posts
Try and get model, be easier to point to different things.

There are two line voltage wires to the airhandler. Reading between the fuses should get 220 volts.

Reading R and C on the terminal board (Small colored wires) should get 24 volts.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: