Changed contactor, now coil ices up

Reply

  #1  
Old 12-12-14, 08:11 PM
A
Member
Thread Starter
Join Date: Dec 2014
Location: United States
Posts: 19
Received 0 Votes on 0 Posts
Changed contactor, now coil ices up

Heat pump was working well. I heard sparking sounds from the outdoor unit and decided to change the contactor. Bought one with the same specs, took several photos before removing wires and replaced it with the new one. I turn on the thermostat, the blower starts working. But now the inside coil freezes up after an hour (the air blower also stops, although no point in blowing chilly air). But the outside fan is still running. Could it be that the new contactor was faulty? Or did I mess up the wiring?
 
Sponsored Links
  #2  
Old 12-13-14, 12:01 AM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 57,774
Received 932 Votes on 869 Posts
Welcome to the forums.

If the condensor unit doesn't shut down then the inside coil will ice up if the blower isn't running. In heatpump mode the refrigerant lines coming inside from the condensor should be warm/hot.

Your thermostat probably shuts off the inside blower and removes power from the reversing valve which will switch unit back into A/C mode if the compressor doesn't shut down.

It would appear that you miswired the contactor. Can you shoot and post some well lit clear pictures of the contactor wiring. The make and model of the condensor unit would be helpful too.

http://www.doityourself.com/forum/el...rt-images.html
 
  #3  
Old 12-13-14, 02:39 PM
A
Member
Thread Starter
Join Date: Dec 2014
Location: United States
Posts: 19
Received 0 Votes on 0 Posts
Thanks for the reply.

This is the old contactor and the wiring
Name:  20141209_095346.jpg
Views: 604
Size:  32.6 KB
Name:  20141209_095048.jpg
Views: 559
Size:  35.0 KB

This is after installing the new contactor
Name:  20141213_113921.jpg
Views: 418
Size:  35.6 KB
Name:  20141213_113831.jpg
Views: 464
Size:  29.1 KB

The make and model of the outside unit is Payne ph10ja024-e

I pushed in the wiring today to ensure proper contact after taking the photos and turned it on. The heat pump raised the temperature from 57 to 67 and the refrigerant lines were hot and no ice formation , but it was not very cold outside, so maybe it did not go into defrost mode and stay there . I will turn it on tonight and run it when it is colder outside and write an update.
 
  #4  
Old 12-13-14, 07:25 PM
Houston204's Avatar
Forum Topic Moderator
Join Date: Oct 2009
Location: Texas
Posts: 7,426
Received 17 Votes on 14 Posts
It looks like you correctly installed the contactor.

Does the outdoor unit now turn off when the stat is satisfied?
 
  #5  
Old 12-14-14, 04:26 PM
A
Member
Thread Starter
Join Date: Dec 2014
Location: United States
Posts: 19
Received 0 Votes on 0 Posts
The coil froze again. I am wondering maybe it is accidental that this started happening after I changed the contactor.
It heats up well and refrigerant line is very hot, but then after I hear a noise outside (probably defrost mode kicking in) it blows cold air, and then the coil ices up. I think it gets stuck in defrost mode. Any suggestions?
 
  #6  
Old 12-14-14, 04:40 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 57,774
Received 932 Votes on 869 Posts
Defrost mode puts the heatpump back into A/C mode and uses the warm air inside the house to defrost the outside condensor. The defrost should be a short cycle. 20-30 minutes as a guess. Usually during defrost the reheat coils are turned on inside the air handler to keep the flowing air warm inside the house.

Do you have electric coils in your air handler ?
What is the outside temperature there now or what was it when the inside coil froze up ?
If you shut the heatpump off at the thermostat... does the outside unit shut off too ?
 
  #7  
Old 12-14-14, 05:21 PM
A
Member
Thread Starter
Join Date: Dec 2014
Location: United States
Posts: 19
Received 0 Votes on 0 Posts
No Electric coils I think. Outside is 42 F. The fact that it switches to AC and keeps at it until the whole coil is frozen is weird.
Yes the outside unit shuts off when I switch it off at the thermostat.
 
  #8  
Old 12-14-14, 05:29 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 57,774
Received 932 Votes on 869 Posts
It uses the inside heat of the house to unthaw or defrost the outside condensor.
Reduced air flow across the inside coil will cause it to freeze up.

I'm trying to find out what puts your unit into defrost mode.

Is the filter in good shape?
Is there good airflow coming outof the registers ?
 
  #9  
Old 12-14-14, 07:40 PM
A
Member
Thread Starter
Join Date: Dec 2014
Location: United States
Posts: 19
Received 0 Votes on 0 Posts
The filter has been replaced and in good shape and a lot of air coming out of the registers. Warm at first and then it got cold, probably when it kicked into defrost mode and stayed there.

Since this all happened after changing the contactor, I am just gonna try another contactor and see how that goes.

One question on the board of the outside unit, this white part gets very very hot (shown in image). What part is that and is it normal to for it to get that hot?

Name:  20141214_214208.jpg
Views: 589
Size:  30.2 KB
 
  #10  
Old 12-14-14, 08:52 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 57,774
Received 932 Votes on 869 Posts
That part looks like a ceramic power resistor and they do usually run hot.

How long is the outside unit staying in defrost ?
You could also be low on refrigerant ?

If the outside unit is shutting down when the t'stat tells it to.... the contactor is doing its job.
 
  #11  
Old 12-14-14, 09:57 PM
A
Member
Thread Starter
Join Date: Dec 2014
Location: United States
Posts: 19
Received 0 Votes on 0 Posts
When it goes into defrost, it just stays there until the inside coil turns into a block of ice. Let me add again that it does heat up, yesterday the refrigerant line nearly burned my hand, haha!

Low Freon...Maybe, I read this somewhere, don't know if it is true:
For Heat Pump systems that run as flooded evaporator type systems, low freon levels will cause extreme icing of the evaporator. This can cause the internal unit to become a solid block of ice during the AC season and for the external unit to do the same during heating season.

According to this the outside unit should ice up in the winter?
 
  #12  
Old 12-14-14, 11:03 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 57,774
Received 932 Votes on 869 Posts
Well yes..... the outside unit does ice up or can ice up and then the unit reverses and the inside coil becomes the cold coil again trying to extract heat to be used to defrost the outside coil.

Maybe my partner, Houston, has a better idea.
 
  #13  
Old 12-15-14, 08:43 AM
A
Member
Thread Starter
Join Date: Dec 2014
Location: United States
Posts: 19
Received 0 Votes on 0 Posts
I was going through the forums, I saw someone suggested changing the time delay relay. He had this problem in summer, his AC would not work at night. I thought I'd give that a shot (I know, that's desperation ). Is that the black part on the circuit board on the bottom left of the last photo?

Or I can just change the whole board. I have another unit so I can just switch their boards and see what the problem is.
 
  #14  
Old 12-15-14, 09:35 AM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 57,774
Received 932 Votes on 869 Posts
The defrost board is a complete unit so it would probably be best to swap the whole board. Make sure all the wires are marked or take some pictures of it to aid in reconnection.
 
  #15  
Old 12-15-14, 10:35 AM
Houston204's Avatar
Forum Topic Moderator
Join Date: Oct 2009
Location: Texas
Posts: 7,426
Received 17 Votes on 14 Posts
The defrost timer has at least one sensor clamped to the outdoor coil tubesheet. The sensor probably has 2 pink wires.
Is it still connected to the ubend or has it fallen off?

Name:  Payne PH10.jpg
Views: 871
Size:  46.5 KB
 

Last edited by Houston204; 12-15-14 at 03:58 PM.
  #16  
Old 12-15-14, 08:10 PM
A
Member
Thread Starter
Join Date: Dec 2014
Location: United States
Posts: 19
Received 0 Votes on 0 Posts
I'll check the sensor tomorrow.

Tonight I turned on the thermostat and it was blowing cold air, and the outside fan was working (why doesn't the fan go off if it is in defrost?). I tried to force the unit in defrost mode by unplugging the pink wires and shorting the plugs, then I shorted the speed up pins. I was hoping the fan would turn off. I shorted them for a minute, nothing happened. Why would the fan not stop if it is in defrost mode? (or why was it not forced into defrost?)
 
  #17  
Old 12-15-14, 08:54 PM
Houston204's Avatar
Forum Topic Moderator
Join Date: Oct 2009
Location: Texas
Posts: 7,426
Received 17 Votes on 14 Posts
It sounds like you might need a defrost timer.
It would be a good idea to test the defrost thermostat on the other side of those 2 pink wires.

http://dms.hvacpartners.com/docs/100...06/38-10sm.pdf
 
  #18  
Old 12-17-14, 09:53 AM
A
Member
Thread Starter
Join Date: Dec 2014
Location: United States
Posts: 19
Received 0 Votes on 0 Posts
Houston, is the defrost timer on the circuit board?
Thermostat sensor is probably a good place to start

The circuit board was OK (switched their boards with each other). One thing I noticed when switching on the system, the pros will probably know what this could mean:
The system that works starts working and powers up when the thermostat sends the signal for heat.

The system that does not heat, clicks and after 4-5 seconds the fan starts running.
 
  #19  
Old 12-17-14, 04:36 PM
Houston204's Avatar
Forum Topic Moderator
Join Date: Oct 2009
Location: Texas
Posts: 7,426
Received 17 Votes on 14 Posts
Yes the circuit board on your heat pump is a defrost timer.

The manual that I posted gives you instructions for also testing the defrost thermostat with an Ohm meter.

Is the defrost thermostat still clipped to a ubend of the heat pump coil?
 
  #20  
Old 12-17-14, 06:01 PM
A
Member
Thread Starter
Join Date: Dec 2014
Location: United States
Posts: 19
Received 0 Votes on 0 Posts
Yes, it was clipped. Pretty awesome manual though, Thanks! I will check the thermostat in get back to you.
 
  #21  
Old 12-18-14, 03:46 PM
A
Member
Thread Starter
Join Date: Dec 2014
Location: United States
Posts: 19
Received 0 Votes on 0 Posts
If I disconnect the defrost thermostat(the pink wires from the board), if the problem is from the thermostat, it should not go in defrost though, right?
 
  #22  
Old 12-18-14, 06:24 PM
firedawgsatx's Avatar
Member
Join Date: Jul 2013
Location: USA
Posts: 1,727
Received 0 Votes on 0 Posts
In my opinion, you are correct in your thinking. If the defrost board is working as designed, the defrost operation should not start unless the defrost thermostat is closed. The defrost board is settable to check every 30, 50 or 90 minutes of run time. After the set run time has been reached the defrost board checks to see if the defrost thermostat is closed because it is cold enough to close the switch. If closed, it will start defrost operation. If open, defrost will not occur. With the defrost thermostat removed it should show as open when defrost board does it's check.
 
  #23  
Old 02-19-15, 08:40 PM
A
Member
Thread Starter
Join Date: Dec 2014
Location: United States
Posts: 19
Received 0 Votes on 0 Posts
OK. Finally got around to ordering everything and getting it fixed.
Symptoms: The indoor coil was freezing into a block of ice in winter. The outside unit started after 5 sec delay after hearing a click sound. (this happened after changing contractor, but was completely unrelated to that).

Solution: Unplugged the pink wires from the defrost board and it would work. The unit will not go into defrost though. Changed the defrost sensor and everything works now. Tested the the old defrost sensor and it was not working indeed.
 
  #24  
Old 02-19-15, 08:44 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 57,774
Received 932 Votes on 869 Posts
Good job. Just in time for the big freeze.
 
  #25  
Old 02-20-15, 02:15 PM
Houston204's Avatar
Forum Topic Moderator
Join Date: Oct 2009
Location: Texas
Posts: 7,426
Received 17 Votes on 14 Posts
I'm glad that you were able to get er fixed

Big freeze? I'm ready for some hot weather and overtime.
 
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: