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  1. #1
    Join Date
    Feb 2012
    Posts
    17

    Problem with new Amana 18 SEER heat pump

    We just had a new Amana 18 SEER heat pump installed in our Southern Indiana home Jan 3 and have had nothing but problems ever since. Condensing unit is ASZC180481AC, Air Handler is AVPTC426014AA and ComfortNet communicating thermostat #CTK01AA. We replaced an older 12 SEER 3 ton Bryant heat pump that was having issues. We have a 1647 SF one-story home (over a crawl space)that we bought 3 years ago and gutted 90% of it and reinsulated prob. 90% of all exterior walls, installed new construction Low E argon-filled windows and replaced all but one exterior door. Needless to say, the house is not drafty. We had a larger 4 ton unit installed because we are adding an addition onto the house this spring. We also had all new duct work installed because we previously did not have any cold air returns in the house.

    Now the issue. Our first electric bill was $438 from 12/15 to 1/19 (avg 117.85 kw/day and Avg daily temp 39). We had to run on EM heat strips (10 Kw) from 12/15 to 1/3 when the new heat pump was installed. The new heat pump constantly cycled on & off. Sometimes it was 3 minute on/off cycles and sometimes at night it would be off for 10 min & then run for hours. We had it set at 68-70. We had the installers out at least 2-3 times each week during January because of the constant cycling. It warmed the house, but it ran at least half the time.

    Between 1/19 (when the meter was read) and 1/29, we used 1186 Kw (Avg 118.6 Kw/day). We talked to the installers again and said something had to be done because we were using as much electricity as we had when we were running on EM heat strips with the old unit! They were calling Amana and trying various suggestions. Nothing helped. We finally said we wanted another unit and they agreed to replace it.

    New unit installed 2/8 and nothing has changed. It was still running short cycles. Amanda tech rep here on 2/10 (left vehicle running in the driveway and brought nothing but a notepad). Suggested running shielded new thermostat wire because he thought it was high voltage interference. Told us that there was no way this unit was causing our high electric usage and left. Wire changed -- no change. Between 2/8 & 2/14 we used 712 Kw (Avg 118 Kw/day). In desperation, we turned off the furnace on 2/14 for 24 hours and continued to use everything else as normal. Used 50 Kw in 24 hours and temp in house dropped 11 degrees.

    Does anyone have any idea what could be causing the constant cycling and high electric usage? Thermostat does not show EM being used at any time.

  2. #2
    Join Date
    Jun 2003
    Location
    Jacksonville, FL.
    Posts
    4,313
    Are you getting any error messages on your tstat? The system has a wonderful system of diagnostic lights that usually are quite capable of pointing techs in the general direction of what's wrong....
    WHY?

  3. #3
    Join Date
    Feb 2012
    Posts
    17
    Not according to the installer or the Amana tech rep. We have used 3 different ComfortNet thermostats and they tried another (I think) Honeywell that was a non-communicating tstat. We had the same issues no matter what tstat was used.

    They tried recharging the first unit. They have now put in 2 drops in our crawl space just to see if it made any difference because the installer was getting told it was because the system was too large for our current space. No change in constantly cycling. The warmer it is, the less it cycles. When the temp outside gets below 35-40 degrees, that is when it really begins to cycle on and off. Frequently, the cycles are around 14 min. on & 14 min. off.

  4. #4
    Join Date
    Feb 2012
    Posts
    17
    The installer has run out of ideas. The factory rep doesn't seem to have any idea. Last night, the unit ran for 4 hours continuously and the outside temp was 38 when it started and 34 when I finally turned the thermostat down from 68 to 66 so it would stop running for a while and went to bed.

  5. #5
    Join Date
    Jul 2004
    Location
    Massachusetts
    Posts
    6,826
    On what basis was the unit up sized to 4.0-tons. I know you said you're going to add on but did they do a real room-by-room load analysis or just assume since you said you're adding on, that you needed a 4.0-ton system? If they did do a load analysis, did the design the new ducts to Manual 'D'? Does your thermostat give you the static pressure in the system? If so, what is it? If not, you should request a static pressure check because a variable speed blower motor pushing against a high static will eat HUGE amounts of electricity. Variable speed blowers are great but they cannot tolerate undersized ducts that result in high static pressures. This is a 2-stage system so does your t-stat show it as operating in 1st stage or 2nd stage at 38F? If it's short cycling, are your positive it's not locked into 2nd stage below 40 or some such? It would be called HP latch up temperature in all likelihood. FYI, if the unit is approaching the 1st stage heating capacity of the system at say 34F, I'd expect it to be operating non-stop or nearly so. When it can no longer hold set-point on 1st stage, it should then cycle up to 2nd stage for a while and then again stage down to 1st stage. That would be constant operation, just maintaining room temperature but also be normal operation for a 2-stage system.
    If YOU want change, YOU have to first change.

    If you are waiting for the 'other guy' to change first, just remember, you're the 'other guy's' other guy. To continue to expect real change when you keep acting the same way as always, is folly. Won't happen. Real change will only happen when a majority of the people change the way they vote!

  6. #6
    Join Date
    Jun 2003
    Location
    Jacksonville, FL.
    Posts
    4,313
    Well, I'm sorry, but I'd have to take a look @ it personally to get some kind of idea.
    My first instinct is that something's not wired right or set up right....
    WHY?

  7. #7
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    66,758
    You have a house that probably needs 2.5 tons since you made those improvements. That has a 4 ton unit, that has no place to go with the air it needs to move.

    A bit late now. But almost always better for any sizable addition to have its own unit.

    Probably about the only thing o do besides tear it out and get a properly sized one. is to have them dump all of the excess air to the crawlspace, and add returns to it to get the air flow up to where it should be.
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  8. #8
    Join Date
    Feb 2012
    Posts
    17
    We told them we had a 3 ton system and explained the size of the room addition (500 SF) that we were planning. We do have a vaulted ceiling in our great room/dining room area and regular 8 ft ceilings throughout the rest of the house.

    They did not do any load analysis and NONE of the 8 companies that we got estimates from said anything about doing one. They all said we needed a 4 ton unit so we assumed it was what we needed.

    We have asked them to do a static pressure test and they have not done one. The factory rep did not suggest one and he said there was sufficient cold air returns (Of course, again, he left his vehicle running in the driveway so he did not anticipate staying very long). He said everything was running like it should but could not explain the frequent run times. They have removed the pleated air filter and left it open to see if it was because of restricted air flow. No change. Now they have installed 2 drops into our crawlspace to compensate for the oversized unit. No change.

    When it is running in these short cycles, it is primarily running in 1st stage. It will occasionally ramp up to 2nd stage for a minute or two and then goes back to 1st stage.

  9. #9
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    66,758
    They sized you by sq ft. not by the heat gain and loss of your house. A 50 sq ft addition didn't/won't add 1 ton to the size you need.

    In first stage, its running 75 and 80% of its full capacity.
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  10. #10
    Join Date
    Aug 2011
    Location
    Eastern Shore, MD
    Posts
    798
    id check youre airflow....then your charge. tech support doesnt like to do that

  11. #11
    Join Date
    Feb 2012
    Posts
    17
    They recharged the first unit they put in and it didn't change anything. They said it was very difficult to determine the charge needed in the winter but they said their head pressure was right.

    Unfortunately, the installers have done all they know or have the equipment to do, apparently. The factory rep only brought a note pad and did not have any equipment to analyze anything.

    We have been keeping track of run times, outside temps, etc. in an attempt to provide more information to them.

  12. #12
    Join Date
    Feb 2012
    Posts
    17
    The installers have told us they will put whatever (Different brand or type of heat) we want in just to make us happy. We were hoping that the first Amana 18 SEER unit was defective and the second one would work okay. Now we continue with the same issues. They have contacted Amana in Houston trying to get tech help also.

    Any suggestions (size, Brand, etc.)? Natural gas is not available. Propane is an option but, due to cost, not as desirable as a heat pump.

  13. #13
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    66,758
    Did the old 3 ton heat and cool your house ok.
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