Page 1 of 2 12 LastLast
Results 1 to 13 of 14
  1. #1

    Heat Pump Problem - Rheem

    I had a new Rheem system put in last May '08:
    Heat Pump: RPNL030JAZ
    Furnace: RGFD07EMCKS
    Thermostat: (-)HC-TST411MDMS (The modulating model)

    My understanding is that in heat mode the heat pump should not come on once the outside temp goes below some programmed value. I think I remember the installers say that that value was 35 or 38 degrees. That has worked fine but once the outside temperature warms back up the heat pump is not coming back on.

    I called my installers and they came out and looked things over. The guy said the furnace filter was clogged and that was triggering a pressure switch to keep the heat pump off. So I made sure the filter was clean all the time but the problem returned. I could reset the system by turning off the breakers for a few minutes when it happened but it was happening every time and the filter was clean.

    So I had them come out again and this time another guy said he "changed the path of 24v common from through defrost board to thermostat." Well, the heat pump is working now but it is coming on well below 35 degrees and I noticed that ice is building up inside the unit.

    I worried that with the heat pump not starting and stopping at the proper temperature I'm not getting optimal efficiency, and I'm worried that the ice will damage the unit. I'm about to lose confidence in my installers & I'd like some other opinions on what should be done.

  2. #2
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    66,817
    The heat pump running when outdoor temps are below 35, won't hurt it.
    Heat pumps with electric aux heat run when its -10 outside.

    The last tech may have had to lower the lock out temp to test teh unit. And forgot to reset it.

    Depending on your electric and gas rate, the HP may be more eeficient then the gas at temps well below 20F.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  3. #3
    Join Date
    Mar 2007
    Location
    Myrtle Beach, SC
    Posts
    2,919
    Heat pumps getting frost on the outdoor unit is normal operation. It has circuitry in it to defrost the outdoor coil periodically. I would not worry about that. It will switch to the gas furnace when the heat pump can't heat on it's own.
    Remember, Air Conditioning begins with AIR.

  4. #4
    Thanks for the replies.

    I checked the setting for the heat pump operation. It is at 35 degrees. So since it is considerably below that now I'm thinking the heat pump should not be coming on at all. Is that right?

  5. #5
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    66,817
    It depends on how far below 35 it is.
    There is a dead band in that setting.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  6. #6
    Join Date
    May 2000
    Location
    Indianapolis, IN, USA
    Posts
    33,415
    Is the outdoor temp displaying properly in the upper left of the screen? If so and the heat pump is definitely running below the 35 degree setpoint, got a bad stat.

    My pump shuts off at 20 out but I keep the house rather cool. In the low 20s, the heat pump runs about continuously even so. But in our area, still cheap heat. I don't set customer's changeover that low.

  7. #7
    BaldLoonie, I looked at the manual for the thermostat to see if things were set up properly. There is an outside temperature sensor on the heat pump but as far as I can tell from the thermostat setup it isn't using it. I turned the unit to 'off' and took a look at the settings. The 'df' setting is at 35 but the 'remote' setting is at off. I tried to set it to on and 'outdoor remote' but all the unit did was blink 'outdoor remote' with some dashes below it in the upper left area when I set the unit back to heat. Is there something else I should have set?

  8. #8
    Join Date
    May 2000
    Location
    Indianapolis, IN, USA
    Posts
    33,415
    Menu reference number 25

    gotta turn remote on then next option is indoor or outdoor remote so say outdoor

    if you still get the 3 dashes, something is wired wrong or the remote has failed. Need to have your installer check it. I had a tech change a stat and the outdoor remote stopped working. Got him a new remote, still no luck. Wouldn't let him walk off the job again, went out only to find that the dumb #$#* wired the sensor in wrong.

  9. #9
    I called Rheem and asked them to get involved on this. A guy from my installer came out today and discovered that they installed the wrong outside sensor on the initial install. I had reservations that the system was installed correctly and voiced them to the install company several times and was always (until today) assured that it was installed correctly. At this point I have no confidence in the installer company and am worried that the unit has been damaged and its service life shortened.

    I got a money back guarantee when the unit was installed & I have asked that it be honored. I was told that they will call me back to schedule a time to remove - we'll see.

    Thanks to everybody for the replies and help.

  10. #10
    Join Date
    May 2007
    Location
    Alabama
    Posts
    909
    There's no damage to the unit because of an oudoor sensor. You have a good unit, I would not have it removed because of the wrong sensor being installed. Every other part of the install might be A+. Your next install could be alot worse.

  11. #11
    Quote Originally Posted by BamaCool View Post
    ...I would not have it removed because of the wrong sensor being installed...
    That is not why I'm having it removed.

  12. #12
    Join Date
    May 2007
    Location
    Alabama
    Posts
    909
    OK then

  13. #13
    Join Date
    Jul 2008
    Location
    Dutchess County, NY
    Posts
    152
    sometimes tstats are programmed with an undetermined or non settable feature. this feature will not allow the heat pump to come back on until the temperature reaches above the determined setpoint you selected by 5 degrees or more.... in other words, your heatpump locks out at 35 degrees, it may not come back on till the temp. reaches 40! some refer to this as "droop" temp setting....

Page 1 of 2 12 LastLast

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