Heat pump going into defrost cycle when cooling?

Reply

  #1  
Old 05-17-20, 07:34 PM
W
Member
Thread Starter
Join Date: Dec 2019
Posts: 6
Received 0 Votes on 0 Posts
Heat pump going into defrost cycle when cooling?

Had an A/C company come out to look at our Goodman 3 ton heat pump. They installed a new control board in the condenser. Ever since the heat works fine but when trying to cool it will go into defrost cycle and blow warm air into the house which defeats the purpose of the cooling mode.. I tried to explain to the repair guy that it was doing this and even though my wife has felt the warm air coming out of the registers in between cycles of cool air he doesn't believe it's happening. Any suggestions as to why this is doing this? It never happened before but since the new control board was installed it happens all the time.
 
Sponsored Links
  #2  
Old 05-17-20, 08:28 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 56,343
Received 741 Votes on 696 Posts
As far as I know..... with power on the O (reversing valve) line ....... the defrost board should not be active since the system will be in A/C mode.

Post the model number off the condenser.
 
  #3  
Old 05-17-20, 10:52 PM
W
Member
Thread Starter
Join Date: Dec 2019
Posts: 6
Received 0 Votes on 0 Posts
It's a CPKE30-1B

Come to think of it he messed around with the wires by the air handler too the day he installed the circuit board.
 
  #4  
Old 05-18-20, 09:54 AM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 56,343
Received 741 Votes on 696 Posts
There are several boards that can be used in there between OEM and universal replacements.
The most common replacement is the ICM control. Based on the wiring diagram..... there may be a problem with the defrost thermostat. As far as I can tell.... that sensor needs to get close to freezing temps before it tells the board to start defrosting.

Name:  def.jpeg
Views: 37
Size:  37.8 KB
 
  #5  
Old 05-18-20, 05:03 PM
W
Member
Thread Starter
Join Date: Dec 2019
Posts: 6
Received 0 Votes on 0 Posts
Thanks for the info.

I work nights so I sleep during the day, woke up this afternoon and warm air was coming out the vents. I checked outside and the compressor was running but the condenser fan was not. A couple minutes later and it started blowing cool air and the condenser fan kicked back on so it definitely is going into defrost mode even though it high 70's, low 80's outside.
 
  #6  
Old 05-18-20, 05:13 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 56,343
Received 741 Votes on 696 Posts
Are you sure it's not just the fan with a problem ?
The fan could be shutting down on thermal overload.
The only way to know for sure is to check the fan's AC power.

You can usually tell when the unit shifts in and out of defrost as the compressor will make some type of noise as the refrigerant valve changes.
 
  #7  
Old 05-18-20, 09:49 PM
W
Member
Thread Starter
Join Date: Dec 2019
Posts: 6
Received 0 Votes on 0 Posts
I wondered about the fan being thermally protected and shutting itself down to keep from burning itself up too. It does make a loud woooshing noise before the fan kicks back on. I ordered a defrost thermostat, it was only $8, I'll install it when it gets here and see what happens.
 
  #8  
Old 05-22-20, 12:03 PM
S
Member
Join Date: May 2019
Location: USA
Posts: 24
Received 0 Votes on 0 Posts
The only way it could blow warm air in defrost mode is if the backup heat strips are wired to come on to prevent that cold blast of air in the winter. Sounds like it's definitely going into defrost mode so I'm guessing they wired it back up wrong. Why don't you get them to come back and fix their mistake?
 
  #9  
Old 05-22-20, 02:21 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 56,343
Received 741 Votes on 696 Posts
It does make a loud woooshing noise before the fan kicks back on.
That loud noise is the changeover out of defrost.
Your system is going into defrost when it shouldn't be.
 
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: