Heat Pump not staying on

Reply

  #1  
Old 02-08-14, 02:26 PM
E
Member
Thread Starter
Join Date: Feb 2014
Posts: 24
Received 0 Votes on 0 Posts
Heat Pump not staying on

Been dealing with this issue for probably a month or more now. Had brand new everything installed last spring as my unit stopped working and it gets very hot in Alabama with no AC. Installer was a relative of a relative, seemed to do a decent job and everything was working. Then it got relatively cold (~5 degrees F) for several days here and I noticed that the house temperature was rather low and thermostat read AUX heat running. Started watching and noticed my outdoor unit was not running at all. Called the installer, he came out and said the unit was working fine. But the problem continues. I can switch off the thermostat, wait for the air handler to shutoff, then switch back to heat and the heat pump fires up and runs for ~5 minutes. I've even watched it shut-off, defrost, come back on for a few minutes, then abruptly stop and will not come on again. Eventually the t-stat will read AUX heat again and will stay in that mode pretty much constantly. Occasionally the outdoor unit may run again for a moment, but its not always functioning when the t-stat is calling for heat as it should.

I had another company come out yesterday after dozens of calls to my installer who keeps saying he will come but never shows. The other company tester also tested the unit and said it was working fine, told me it was a problem with my thermostat and left. Installed a new thermostat, everything continues to operate as before.

I've been trying to find a more detailed description of each wires meaning on the thermostat to see which lines actually return values to the t-stat and which only send signals to see if its a problem with how the t-stat is wired. I've also been given the understanding that AUX heat should only activate when the temperature is far below the set temperature (I keep at 69), but it shows to be running AUX heat when at 68 or 69 degrees.

Any insight would be a major help, I plan on calling the second technician again and making them come back out, but having some more knowledge to throw at them would be a great help.

Thanks!
 
Sponsored Links
  #2  
Old 02-08-14, 08:02 PM
Houston204's Avatar
Forum Topic Moderator
Join Date: Oct 2009
Location: Texas
Posts: 7,426
Received 17 Votes on 14 Posts
Aux controls your electric heat strips and will be energized with a little as a 2 degree demand.

An example of thermostat control with a common color code (but color codes vary)...

 
  #3  
Old 02-10-14, 05:29 PM
E
Member
Thread Starter
Join Date: Feb 2014
Posts: 24
Received 0 Votes on 0 Posts
Okay, so the company came back out, looked at the new thermostat I installed and said everything was fine and left. Its not, my unit won't run.

My new thermostat has the following connections:

G B O Y RC RH W2 A W1 C

I wired it in the following manner according to the previous wiring and the specifications for the thermostat:

G - connected to G
O - connected to O
Y - connected to Y, with jumper to W1
RC - connected to R, with jumper to RH
W2 - connected to W2
C - connected to C

What sort of readings should I be getting between the different terminals. Could anything in this wiring possibly cause my Heat Pump to not be activating properly? As stated before, it always comes on when the thermostat is turned to the "Off" position, wait for the air handler to shut off, then switch back to "Heat". But it only runs for a few minutes before shutting off. It will also sporadically turn on for a couple minutes, but its no more than once or twice a day, and only for a few minutes.

Are there any other tests that I can perform on the system to see why it refuses to operate normally?

Thanks,
Everett
 
  #4  
Old 02-10-14, 06:48 PM
Houston204's Avatar
Forum Topic Moderator
Join Date: Oct 2009
Location: Texas
Posts: 7,426
Received 17 Votes on 14 Posts
Verify that you have 24 volt AC between C and Y to the outdoor unit when it has a demand but is not running.

A 24 signal to Y should run your outdoor unit.

Some heat pumps have an outdoor thermostat that will turn off the heat pump below a certain temperature. 5 degrees is certainly a temperature that I would expect to lockout the heat pump if it has an ODT. The make and model might help to verify if you have an ODT. A few pictures of the inside of the electrical compartment of the outdoor unit wouldn't hurt either... Photo and image hosting, free photo galleries, photo editing

The jumper between Y and W1 is common with older Honeywell and newer budget thermostats like Lux and Hunter. What make and model stat do you have?
 
  #5  
Old 02-10-14, 07:45 PM
E
Member
Thread Starter
Join Date: Feb 2014
Posts: 24
Received 0 Votes on 0 Posts
Ugh, this site logs people out entirely too much. Lost my whole post.

The 5 degrees that I spoke of was a real oddity lasting a couple days, but that was over a month ago, and the same time that I started noticing that the unit wasn't working properly. Since I've seen 50 degree days where the outside unit is not running while the thermostat is calling for heat.


The thermostat is a Lux. The old stat that was "supposedly" bad was an Emerson.

Y reading at outside unit:
On:
27.24
Off:
27.86

The unit has a Guardian label on it. Model # GHGD30S21S1B
A quick search provided:
B72-525 | Evcon | GHGD30S21S1 | Johnstone Supply

And a technical guide:
http://www.virginiaair.com/docs/techguides/ghgd-2.pdf

Now I did take some readings off the thermostat, and other than connecting from R to C (27.24), everything else read less than 1V. At first it seemed like something was wrong, but I believe once the faceplate is removed, nothing remains to produce a signal.

When I was first messing around with the unit a little while ago, I decided to try something different. After the unit ran its normal cycle, I switched off the outside breaker to the unit and tried switching it back on. Nothing happened. So I switched it back off and started taking the casing off to see what wires were coming in from the house. As I was inspecting the wires, I heard a noticable pop, followed by a draining sound from the unit. Switched the breaker back on and the unit started running again. If I'm not mistaken, that would be a relay.

I will follow up with some pictures shortly.
 
  #6  
Old 02-10-14, 08:05 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 58,593
Received 1,045 Votes on 969 Posts
Everett..... in the future if you have a problem losing a post..... go to the bottom of the reply page and click on restore auto-saved content and the system will restore your post. This board auto-saves your postings every 15 seconds or so. See the pic below.

Name:  auto.JPG
Views: 650
Size:  17.1 KB
 
  #7  
Old 02-10-14, 08:11 PM
Houston204's Avatar
Forum Topic Moderator
Join Date: Oct 2009
Location: Texas
Posts: 7,426
Received 17 Votes on 14 Posts
Does the heat pump have 240 volts AC to the contactor when it drops out?

 
  #8  
Old 02-10-14, 09:29 PM
E
Member
Thread Starter
Join Date: Feb 2014
Posts: 24
Received 0 Votes on 0 Posts
Across L1 - L2 I have a reading of ~244 VAC, across T1 - T2, its reading about ~0.6 VAC

@PJMax, thanks, the problem was it redirected me to the login screen so I couldn't use that button, nor would the back button on my browser return me.
 
  #9  
Old 02-10-14, 09:57 PM
Houston204's Avatar
Forum Topic Moderator
Join Date: Oct 2009
Location: Texas
Posts: 7,426
Received 17 Votes on 14 Posts
Does the contactor have 24 volts when it drops out (with 24 volts present between C and Y)?
 
  #10  
Old 02-11-14, 09:48 AM
E
Member
Thread Starter
Join Date: Feb 2014
Posts: 24
Received 0 Votes on 0 Posts
With the 27.4 VAC still showing across Y - C, the contactor is showing 0 VAC between the terminals.
 
  #11  
Old 02-11-14, 04:26 PM
Houston204's Avatar
Forum Topic Moderator
Join Date: Oct 2009
Location: Texas
Posts: 7,426
Received 17 Votes on 14 Posts
Sounds like a pressure switch lockout. Looks like that unit has a low pressure switch and a high pressure switch.

I'd try to determine if the 24 volt circuit opens across one of these switches when this problem occurs. You can place one lead on C and check each side of the switch for 24 volts.

http://upgnet.com/PdfFileRedirect/03...001-a-1210.pdf
 
  #12  
Old 02-11-14, 04:43 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 58,593
Received 1,045 Votes on 969 Posts
Everett..... that stored info stays there indefinitely. Doesn't matter if you log out.... or come back days later. If you had something on the page it would be stored. If you look.... that restore text might be there along with your lost post.
 
  #13  
Old 02-11-14, 04:51 PM
E
Member
Thread Starter
Join Date: Feb 2014
Posts: 24
Received 0 Votes on 0 Posts
Okay, both pressure switches are located inside the unit, rather than taking it apart, i traced the wiring back to the circuit board. Each of the two pressure switch terminals on the board are reading 27.84 VAC when connected across the C terminal.
 
  #14  
Old 02-11-14, 06:45 PM
Houston204's Avatar
Forum Topic Moderator
Join Date: Oct 2009
Location: Texas
Posts: 7,426
Received 17 Votes on 14 Posts
Everett, Are you checking common to 3 spots or 4 to get the reading across 2 pressure switches?

PJ, I did not know this information about retrieving lost posts. I often lose my post when trying to add pics. Thank You. I will have to try this the next time it occurs.
 
  #15  
Old 02-11-14, 07:44 PM
E
Member
Thread Starter
Join Date: Feb 2014
Posts: 24
Received 0 Votes on 0 Posts
Currently, I've only been checking the values at 2 locations. As stated, the pressure switches are located inside the unit, making them impossible to reach without taking a lot more apart. I traced the wires, one end of each are going to a large connector block, which I'm assuming is a common hot lead for all the heat pump components. The other ends run into a circuit board, which is where I tested them from. I also realized I never attached pictures, so here they are. At the very top of the first photo you can see a yellow and black wire coming in to a label "Switch", these are the pressure switch hookups and where I am testing



 
  #16  
Old 02-11-14, 08:02 PM
E
Member
Thread Starter
Join Date: Feb 2014
Posts: 24
Received 0 Votes on 0 Posts
I went ahead and cut the zip-tie holding most of the wires together so I could better trace whats coming from and going to different places. One end of each pressure switch runs into a connector linking them together, the other two ends run to the circuit board shown. I am testing 27.84 VAC at both links on the circuit board as well as 28.04 VAC at the link between the two switches
 
  #17  
Old 02-11-14, 09:06 PM
E
Member
Thread Starter
Join Date: Feb 2014
Posts: 24
Received 0 Votes on 0 Posts
I was just looking more at the wiring connections from the thermostat to the outside unit and noticed something peculiar, at least based upon my understanding.

On the thermostat the following connections with wire colors:
G - Green
O - Brown
R - Red
Y - Yellow
W2 - White
C - Blue

On the outside unit:
W1 - Not connected
W - White
O - Green
Y - Yellow
C - Blue
R - Red
X/L - Not connected

By my understanding, the green shouldn't be connected to O as that is the signal to the attic fan, and the brown should be connected to O since thats the reversing valve control.
 
  #18  
Old 02-11-14, 10:50 PM
Houston204's Avatar
Forum Topic Moderator
Join Date: Oct 2009
Location: Texas
Posts: 7,426
Received 17 Votes on 14 Posts
The stat wire runs to the air handler and the heat pump wire runs to the air handler. Can you post the wire connects at the air handler?

A pic of the wiring diagram for your outdoor unit would also help since I cannot find a useful manual for that unit.
 
  #19  
Old 02-15-14, 12:16 PM
M
Member
Join Date: Feb 2014
Posts: 3
Received 0 Votes on 0 Posts
Did you have any luck with this issue? I have been experiencing the same exact symptoms for several weeks now. I had a repair man tell me the defrost board was bad, but i just swapped it out and i'm still having the same problem.
 
  #20  
Old 02-15-14, 02:08 PM
E
Member
Thread Starter
Join Date: Feb 2014
Posts: 24
Received 0 Votes on 0 Posts
Maryland1
Did you have any luck with this issue? I have been experiencing the same exact symptoms for several weeks now. I had a repair man tell me the defrost board was bad, but i just swapped it out and i'm still having the same problem.
No, still haven't figured out what the exact problem is.

The stat wire runs to the air handler and the heat pump wire runs to the air handler. Can you post the wire connects at the air handler?
Stat - Thermostat
A.H. - Air Handler
H.P. - Heat Pump

Stat Green -> A.H. Green
Stat Brown -> H.P. Green
Stat Red -> A.H. Red -> H.P. Red
Stat Yellow -> H.P. Yellow
Stat White -> A.H. White -> A.H. Brown -> H.P. White
Stat Blue -> A.H. Blue -> H.P. Blue

Which explains why the green is connected to the O on the outside unit, but is that correct having the white connect to both white and brown on the air handler? The air handler does not have a yellow connection, which makes sense.

A pic of the wiring diagram for your outdoor unit would also help since I cannot find a useful manual for that unit.
I'm not sure what you are looking for beyond the picture I posted previously. I cannot find any better wiring diagrams for the unit in any of the manuals, so other than trying to draw up something on my own, I don't know that I could provide anything better than the picture given.
 
  #21  
Old 02-15-14, 03:58 PM
M
Member
Join Date: Feb 2014
Posts: 3
Received 0 Votes on 0 Posts
Based on your picture, it looks like we have different units, but our defrost control boards are identical. Here is the schematic that came with the new one i just installed.
 
Attached Images  
Reply
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


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