Bryant heat pump, Auxiliary heat only.

Reply

  #1  
Old 12-28-11, 03:50 PM
M
Member
Thread Starter
Join Date: Dec 2011
Location: usa
Posts: 7
Received 0 Votes on 0 Posts
Bryant heat pump, Auxiliary heat only.

Hi, my Bryant heat pump is 7 years old.
Today I noticed the house was getting colder and I heard the thermostat click like it normaly does when it starts the heat pump.
I went to check and it was 6 degrees below the temperature that we keep the house at.
I tried cycling it to a/c and lowered the temp so that it would turn on, again the thermostat clicked but the heat pump nor the blower would turn on, same as when it was set to heat.
So I tried the eheat, and it is working fine, the house is warm and the blower runs.
I checked the breakers, none have been tripped. I replaced the contactor and the fan motor on the outside unit this summer. I do have a multimeter and am ready to do some troubleshooting, but I'm not sure where to check and what readings to look for.
Any advise?
Thanks
Mike
 
  #2  
Old 12-28-11, 04:02 PM
Houston204's Avatar
Forum Topic Moderator
Join Date: Oct 2009
Location: Texas
Posts: 7,425
Received 17 Votes on 14 Posts
Is the dual capacitor in the outdoor unit swollen on top?
It should be flat on top.

 
  #3  
Old 12-28-11, 07:41 PM
M
Member
Thread Starter
Join Date: Dec 2011
Location: usa
Posts: 7
Received 0 Votes on 0 Posts
Thanks Houston, I'll check that out in the morning and let you know what I find.
 
  #4  
Old 12-28-11, 08:06 PM
Houston204's Avatar
Forum Topic Moderator
Join Date: Oct 2009
Location: Texas
Posts: 7,425
Received 17 Votes on 14 Posts
This is a condenser example, your heat pump will also have a defrost control but this may help...



A heatpump will require 24VAC between Y and C to energize the compressor. It will also require 24VAC between O and C to set the reversing valve in the cooling position.

 
  #5  
Old 12-29-11, 08:53 AM
M
Member
Thread Starter
Join Date: Dec 2011
Location: usa
Posts: 7
Received 0 Votes on 0 Posts
Very helpfull diagram, Thank You.
The capacitor looks good to my eye, still flat across the top.
So I started checking voltages per your diagram.
With a heat demand from the thermostat the contactor had 235v coming into it, and no voltage anywhere else.
While I was checking voltages I somehow engaged the contactor and the heat pump and the air handler both came on. I turned off the heat by lowering the thermostat setting, waited for about 5 min and raised the setting again, the thermostat read "heat on" but neither the air handler nor the heat pump came on. I went out to check the voltages again and ended up with the same readings, and again while checking, being carefull not to short anywhere, the contactor came to life and the whole system started.
While running, on the contactor, I get 230v on 2 ends and 24v on the other 2 wires.
 
  #6  
Old 12-29-11, 11:10 AM
M
Member
Thread Starter
Join Date: Dec 2011
Location: usa
Posts: 7
Received 0 Votes on 0 Posts
To check the voltage between Y and C, I set the thermostat to cooling and lowered the temperature setting. The thermostat read "cool on", but nothing is running. So I went outside and checked the voltage at Y and C where they connect to a circuit board, got no voltage. So I started walking inside and the system started up, this was maybe 5 minutes after the thermostat called for cooling.
 
  #7  
Old 12-29-11, 12:05 PM
M
Member
Thread Starter
Join Date: Dec 2011
Location: usa
Posts: 7
Received 0 Votes on 0 Posts
I turned the unit off at the thermostat and waited for the air handler blower to stop running, turned the thermostat to heat and it came right on.
I did not mention that I disconnected the contactor and cleaned the contacts before the last post.
So I turned the breakers all off reassembled everything, turned the breakers back on and set the thermostat to heat again. It took a couple of minutes from the time that the thermostat read "heat on" till the system came on, but it is on.
Not sure what to make of it, but for now it seems to be working.
Thanks again Houston for pointing me in the right direction.
 
 

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