Page 2 of 3 FirstFirst 123 LastLast
Results 14 to 26 of 29
  1. #14
    Join Date
    Aug 2007
    Location
    MN
    Posts
    2,677
    Quote Originally Posted by RyanHughes View Post
    Hmm, there's a reference to my earlier speculation that it might be overcharged and locking out. Either way I know something's wrong with the system run times being too short. I think I'll look into a new thermostat (which one? ) and a checkup in the Fall to prepare for heating.

    Chuck, no worries; I don't think you're hijacking my thread. I really appreciate everyone's input in my thread here; you all have more knowledge than I do! I just want to make the right decision here. The question I have now is should I go ahead and try to install a new thermostat. I think I'm up to it; I'm good when it comes to electronics.
    I would get the honeywell visionpro, just has to be a HP t-stat.

    Just remember that if you change the stat and fry something cause you hooked it up wrong, you pay for the parts, if the contractor fries parts, they pay for parts
    You can't fix stupid

  2. #15
    Join Date
    May 2007
    Location
    DC Metro Area (MD)
    Posts
    3,371
    How easy is it to fry parts? I'm not that illiterate with wiring. What I would do is just reconnect the wires to the corresponding terminals on the new thermostat as they were on the old one. I just hope everything matches up. I didn't think this was too uncommon for homeowners to do if they had some electrical engineering knowledge. I think one, maybe even two of my close neighbors did it. I wonder what they'd charge for the installation and thermostat itself. I got a quote for one with another contractor to add a VisionPRO to a whole new system and it was higher than I had expected (can't post the price here, though). Oh, and I do have auxiliary heat (electric heat strips) in my air handler.

  3. #16
    Join Date
    Aug 2007
    Location
    MN
    Posts
    2,677
    Quote Originally Posted by RyanHughes View Post
    How easy is it to fry parts? I'm not that illiterate with wiring. What I would do is just reconnect the wires to the corresponding terminals on the new thermostat as they were on the old one. I just hope everything matches up. I didn't think this was too uncommon for homeowners to do if they had some electrical engineering knowledge. I think one, maybe even two of my close neighbors did it. I wonder what they'd charge for the installation and thermostat itself. I got a quote for one with another contractor to add a VisionPRO to a whole new system and it was higher than I had expected (can't post the price here, though). Oh, and I do have auxiliary heat (electric heat strips) in my air handler.
    If you feel you are capable, then go for it, sometimes the terminal designations on those old t-stats are different(lennox was horrible) but your right a smart guy can do it just fine, BUT I have gone out and fixed some really smart guys screw ups because they tried to save a buck. Just remember you have a mismatched system so if the terminal designations are not the same, the wiring schematics for the 2 units might not help you alot.
    You can't fix stupid

  4. #17
    Join Date
    Aug 2007
    Location
    MN
    Posts
    2,677
    I was taught in tech school that all electrical equip. run on smoke.
    If you let the smoke out, it quits working!
    You can't fix stupid

  5. #18
    Join Date
    May 2007
    Location
    DC Metro Area (MD)
    Posts
    3,371
    Haha. Well, I'm going to have to really think about whether or not I want to go ahead and change the thermostat. Could the two units being improperly matched affect the way it would have to be wired? Would just matching the terminal connections from old to new be an unwise choice? Maybe it's time for a... checkup. Any good contractors in the Maryland/Washington D.C. area anyone can recommend?

  6. #19
    Join Date
    Aug 2007
    Posts
    24
    Ryan, Has this "short cycling" only been happening since the new A/H was installed? Or was it doing the same before then? I have installed a lot of electronic t-stats,and even though some you can adjust for slightly wider temp spread between off and on,they generally cycle faster than the old mercury bulb t-stats because they measure temps with a thermistor. That is why I asked if the t-stat was away from any possible(cool) airflow from a supply register hitting it,or conversely is there a light or heat source that could be affecting operation.

  7. #20
    Join Date
    Jul 2007
    Location
    Beautiful, Philadelphia, the City of Brotherly Love!
    Posts
    1,096

    The dash R means factory installed restrictor, the restrictor is supposed to be

    Quote Originally Posted by RyanHughes View Post
    As to that article you are mentioning Kevin, that does alarm me a bit. I don't know if the actual model of my air handler, CB28UH-R has a TXV or not. It seems to be cooling fine, though; the short cylcing is what's got me all confused. I think the first step I should take is getting a new thermostat. Any ones out there you guys recommend? I know about the VisionPRO, but sadly, the thermostat cable I have is 20 years old too, and I don't know if it'll work. It was warm and humid out today. I know that partial change outs are not good at all, and I don't think I would ever have done it if my heat pump was only a few years old when I needed a new air handler. That just seemed wasteful to me. Who knows how long this Payne will last, though. One sales person told me 6-8 years.

    One thing that comes to mind, though: for a house that's 2500 sq. ft., wouldn't 3.5 be enough? I know there are many factors, but we have a good amount of electronics/computers/appliances and the home is 20 years old or so, so I would just think this is enough if not too small. Right now it sure seems like it's way too big. I've never run into a contractor (I've had 3 different ones) that have done a load calculation voluntarily; I guess I'll have to ask. Especially keeping in mind what that article said, if my system wasn't running to its full capacity and still short cycling, that's still pretty strange. Any recommendations on thermostats are still appreciated. I was thinking of the Honeywell VisionPRO 8320, but then a Carrier/Bryant thermostat came to mind because the original unit for the house was a Bryant and I have a Payne now, so maybe the wiring is right for it? Who knows; it was 20 years ago. Maybe something will come along and make me feel comfortable replacing these two relatively new units, but I'd like to get a longer lifetime out of them.
    changed to whatever restrictor the factory supplies with the condensing unit, if they are different. Lennox sells a TXV that will install into this unit as an optional part.
    Attached Images Attached Images

  8. #21
    Join Date
    Jul 2005
    Posts
    5,571
    Quote Originally Posted by RyanHughes View Post
    Hi there,

    I've always felt my system short cycled slightly, but today it just seems to be beyond belief. Seriously, every 5 (give or take a minute or two) minutes the system goes on, and every 5 (give or take a minute or two) minutes the system rests. I don't know why it's doing this other than the fact that it's humid outside. Some speculation has gone through my mind that the system is overcharged and it's locking out (although I doubt it) or my thermostat has become inaccurate over time and now is the peak of its inaccuracy. I know enough to know that this is bad for the components in my system. The air coming out of the vents seems very cool and the house is staying cool, though.

    My equipment is as follows:

    -Payne 10 SEER Heat Pump (installed in 2004 I believe)
    -Lennox 13 SEER Air Handler (installed this summer)
    -Bryant Mercury Thermostat (this is from when the house was built around 1986-1987)

    Please advise me on actions you'd recommend I take. I'm tempted to call back the company that installed the air handler and explain the problem; however, this is the same company that installed the Lennox air handler with the Payne system and assured us everything was fine, so I am tempted to choose another company.

    Thanks,

    Ryan

    Edit: After monitoring it for one cycle and one rest, the intervals seem to be approximately:

    6-7 minutes resting
    14-15 minutes running

    Thermostat is set at 71-72.

    Does this sound normal on a humid day outside?
    It could be normal, yes. It sounds normal. But the t-stat is old, so it wouldn't hurt to upgade to a digital. If you do, and if you adjust the temperature differential, then you'll probably end up with a temperature swing that's too large. You might find that more irritating than short off cycles when its warm and humid out. I'm sure that whoever is living there with you won't think it's an improvement.

  9. #22
    Join Date
    Mar 2007
    Location
    Myrtle Beach, SC
    Posts
    2,919
    Note that when they installed the new indoor unit, they could have installed a Payne to match the outdoor unit. Then the system would have been 10 or 11 SEER instead of ?????.

    Another thing about heat pumps is the indoor coil is the evaporator in the summer and the condenser in the winter. If you add Freon in the winter to bring the heat pressure up to where it should be for proper heating (13 SEER indoor coil has extra refrigerant volume), you may have to take Freon out in spring because now you high head pressure running in cooling. Because the low SEER outdoor can't hold the extra Freon.

    So it is still a bad match.

    If I have an old Lennox indoor unit that can't be changed, I can call Lennox and they will tell me what new outdoor units will match it. They tell me the indoor coil should have 1.4 to 1.8 times the Freon volume of the outdoor coil for proper operation. This is because the outdoor fan moves more air than the indoor blower for a given size of unit. What is the chance that is the situation here?

    Even on a straight AC there are considerations, but on a (reversing) heat pump, the considerations are more critical. It may work, but how well and for how long? Improper charge can cause slugging or high suction superheat. Either can shorten compressor life.

    Not trying to be a jerk, I know this sort of thing is done a lot. Sometimes it seems to work, sometimes not. But almost never as well a a properly matched system., properly installed.

    In the words of Dirty Harry.....So, are you feeling lucky?......
    Remember, Air Conditioning begins with AIR.

  10. #23
    Join Date
    Jul 2007
    Location
    Beautiful, Philadelphia, the City of Brotherly Love!
    Posts
    1,096

    What difference would installing a Payne 13 seer coil have made?

    Quote Originally Posted by Kevin O'Neill View Post
    Note that when they installed the new indoor unit, they could have installed a Payne to match the outdoor unit. Then the system would have been 10 or 11 SEER instead of ?????.

    Another thing about heat pumps is the indoor coil is the evaporator in the summer and the condenser in the winter. If you add Freon in the winter to bring the heat pressure up to where it should be for proper heating (13 SEER indoor coil has extra refrigerant volume), you may have to take Freon out in spring because now you high head pressure running in cooling. Because the low SEER outdoor can't hold the extra Freon.

    So it is still a bad match.

    If I have an old Lennox indoor unit that can't be changed, I can call Lennox and they will tell me what new outdoor units will match it. They tell me the indoor coil should have 1.4 to 1.8 times the Freon volume of the outdoor coil for proper operation. This is because the outdoor fan moves more air than the indoor blower for a given size of unit. What is the chance that is the situation here?

    Even on a straight AC there are considerations, but on a (reversing) heat pump, the considerations are more critical. It may work, but how well and for how long? Improper charge can cause slugging or high suction superheat. Either can shorten compressor life.

    Not trying to be a jerk, I know this sort of thing is done a lot. Sometimes it seems to work, sometimes not. But almost never as well a a properly matched system., properly installed.

    In the words of Dirty Harry.....So, are you feeling lucky?......
    The Lennox coil is a superior product, now when the old Payne craps out his installer can supply a 13 seer or higher outdoor unit, with a TXV is he so chooses. The Lennox coil can be adapted to 410a also.
    I agree with you on the heat pump mode, this is a crap shoot with the refrigerant charge. Obviously there is a price point here as the installer believed the HO didn't want to spend the money for a new thermostat.

  11. #24
    Join Date
    Aug 2004
    Location
    North Richland Hills, Texas
    Posts
    14,914
    Any recent changes to the house, like powered attic ventilator installed, change from a wood roof to composition, etc.?
    If more government is the answer, then it's a really stupid question.

  12. #25
    Join Date
    Dec 2006
    Location
    Middle Tennessee
    Posts
    11,347

    *

    Quote Originally Posted by Kevin O'Neill View Post
    The air handler doesn't KNOW anything.


    LOL



    .

  13. #26
    Join Date
    Aug 2006
    Location
    houston
    Posts
    40

    I have short cycle problem too

    I have a 4 ton carrier package unit to cool two rooms 10X13 & 10X15. With one return duct. The room is a computer room (15 computers and monitors). The t-stat (space sensor) set point is 73 degrees, but the unit comes on like every two-five minutes. and space temp does reach 73 degrees. Superheat 12 subcooling 10. But the room stays humid the miniute it shuts off it feels hot. There is no float switch and drain is working properly. I recommended a humitiy stat but the unit is gas heat. There is no outside air for the return.
    any ideas would help.

Page 2 of 3 FirstFirst 123 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