Coil Freezing
Results 1 to 6 of 6

Thread: Coil Freezing

  1. #1
    Join Date
    Apr 2005
    Location
    Richmond, Virginia
    Posts
    365

    Unhappy

    I've been working on Janitrol 1.5 ton heat pump with a piston metering device. The initial call was a no cooling/frozen coil. I squeezed them in inbetween calls since I was in the neighborhood. I found a leaking shrader, so I replaced it added a pound got the super heat and sub cooling dialed in and told the homeowner there was a possibility there would be more but I didn't have time to look for other leaks. I explained this was temporary fix until I could get back and service the unit.

    I got a call from the home owner a couple of days ago and said the coil was freezing up again. Went out there yesterday and pulled the charge, checked for debris in the piston, blew it out with nitrogen, put in a liquid line filter drier, pressurized to 200 psi (held for 30 min), pulled vacuum held for 30 min, started unit. Here are the conditions I left the unit in:

    Indoor 68 wb 77 db
    Outdoor 85
    Suction line 40 F (68 psi) - 57 F = 15 F super heat
    Liquid line 110 F(225 psi) -88 F = 32 F sub cooling
    These were constant for 30 min.

    Got a call from the home owner saying the coil was freezing up again! But he said it wasn't totally frozen over. I checked the coil it was clean, the filter was dirty but I've seen worse.

    Any thoughts?
    Sean Cantrell

  2. #2
    Join Date
    Feb 2005
    Location
    Dothan, Al
    Posts
    3,453
    Jnitrol hve blower time delay that will sometimes not energize the blower motor - replace the time delay and see if that helps

  3. #3
    Did you check motor amps?

  4. #4
    Join Date
    Apr 2005
    Location
    Richmond, Virginia
    Posts
    365
    I checked compressor amps they were ok. Didn't check blower amps. I'm going back out there this afternoon.
    Sean Cantrell

  5. #5
    Join Date
    Aug 2002
    Location
    manitowoc wisconsin
    Posts
    4,943
    what was the temp drop across the coil?are you moving enough air?
    Take your time & do it right!

  6. #6
    Join Date
    Apr 2005
    Location
    Richmond, Virginia
    Posts
    365
    22 F delta T 650 CFM...

    Replaced relay and cap cycled the thing 10 times. With homeowner standing right there.
    Sean Cantrell

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event