Louisiana Scared of my pumps

Discussion in 'Maintenance and Troubleshooting' started by bjl, Aug 14, 2019.

  1. bjl

    bjl Member

    I have two miami heat pumps, 2.5 ton and a 3 ton 2 stage. Been running since 2015, with few problems. I did the whole installation learning as i went. After the install for the first year everything was perfect till ewt started rising. Started at 68* and at 85* or so the 3.5 ton (now a 3 ton from a blown compressor, which is what the manual j called for) went to high pressure lockout. Figured out not enough water flow. Each unit had a single ups15-42f 1/25hp pump set to high and the same pump for the desuperheaters combined. I installed my swing pump in a push/pull configuration and it solved the problem.
    Fast fwd to now, I haven't installed enough insulation for what the system was desined for and the ground loop temps have been slowly rising. More Insulation is at the top of my list right now, but doesnt explain the pump overheating, i think. One pump on the the 3 ton actually melted the paint in one spot, see pic. 20190814_073135.jpg This pump was locked up, but i guess the other kept it from burning up, maybe. Never triped the breaker. Amp test on each pump is .38, below the .41 max. Housing temps on the 3 ton (both pumps) are at 140* in one spot by the manufacturer connections. The same spot on the other unit pump is 108*. Well last night the desuperheater pump almost caught on fire. This is the same spot I am testing on the other pumps 20190814_072636.jpg
    It almost seems like bad connection leading to overheating, but i dont know for sure. Is this a common problem? Or Do i have something wrong? Maybe need larger pumps?
    Ewt is at 111*
    Lwt is at 120*
    The delta T on both units has stayed at 10* +- 1* since install.
    I am in southern Louisiana (gulf coast)
    Predominantly hot and humid for most of the year.
    Loop field is horizontal unpressurized closed with 8 loops @ 90' spaced out 7' centers buried 10' down. Each contain 680' of 3/4 hdpe.
    It took me 3 years to build this house basically by myself and would hate to see it burn from a stupid pump (i do have small circuit breakers on the pumps)
    please advise!
  2. waterpirate

    waterpirate Well-Known Member Industry Professional Forum Leader

    Hi and welcome,
    grundfos pumps have a wet rotor design. That looks to me like the motor/pump was locked and the unit was calling for the pump. Capacitor could not take it and burned. Just replace the faulty pump and maybe try to filter your loop fluid doing a purge to check for debris.
  3. bjl

    bjl Member

    I finished putting the insulation in the attic. Added another 7 to 8" of cellulose. In just a week the runtimes are slightly lower. With the ewt @ 110* it'll take a couple cooling seasons for everything to settle down to what it should be, i believe. I tried running the units on heat and they go into lockout. My guess ewt is to high. I set a screen well @ about 9' down. My loop field is @ 10' sandwitched in 3' of sand while surrounding land is clay. Watertable is @ 5' down, so my theory was to use a small pump to remove some of the hot water within the layer of sand which will be replaced with much cooler water from below the field. Hopefully i will only have to do this, this one time. Its been running for 3 days now and dont see a drop in temp yet, but i am only pumping maybe 1gpm out the ground.

    Any thoughts on this would be greatly appreciated.

    I did replace my push/pull pump setup to a single ups15 55. The pump housing temps are still to hot to touch. Hanging around 140*.

    *Would these temps fall as i get my ewt down?

    *afterthought, should i go with a larger pump like ups26 99, and on my 2.5 ton run on low speed, on my 3 ton, stage 1 low speed stage 2 med speed?
  4. bjl

    bjl Member

    Hi Eric,
    Forgot to mention the pump in the picture is on the desuperheater in which i do have city water but does have alot in minerals. We get this pinkish calcium looking buildup. I believe it is manganese but never had it tested. The pump did have some buildup on it a i did clean it the previous day. The capacitor seems to be fine, i will test it to be sure. All the burned parts were on the pump contacts and the soot turned capacitor black.
    *could this be from running the pump dry?
    While replacing it, it dawned on me that i started the pump before opening the isolation valves. It was only 10 sec or so but it was ran.
  5. JD B

    JD B Member

    This may sound really stupid - but did you have a storm with lots of lightening around the time your pumps fried? Your burned pump elect. connection resembles my electric water heater - both elements at connections and unit connection were charred - burned - melted from a close lightening strike that damaged it, the HP condenser, my coffee pot, phones and other electronic items a few years ago. This year a strike hit near enough it shook my home and took out my well pump.

    The WH was in my basement and all its wires had clearly been on fire. Given the breaker boxes and big ticket 220v items installed in basement - I've installed smoke detectors down there. Anyway, given your pumps had been working correctly - could it have been a massive power surge?
  6. bjl

    bjl Member

    Hi jd b, sorry haven't been on in a bit. Im pretty sure no powee surge. My pumps run on tge same circuit as the ac unit and it has no issues besides high ewt. I find it peculiar that was the only pump inadvertantly was started dry and fried.
    New issue that arose was my domestic hot water temp shot up to like 140*. It has never been that hot. Does this mean to high of head pressure? My ground water temps were dropping then a coupl days of longer runtimes and its back up to 100*.
    And now... the big issue. My house stinks. After foaming my light fixters and vent box penetrations, i finished insulating to an r-38. That night the oder started mildly and got worse. Smells like an amonia base cleaer, which means mold as far as i can tell. I found a wet area under a tub enclosure and mold. Thought it was the problem so cleaned it thoroughly but the order is persisting. Checked both ac units, vents, exterior walls, under windows, walls and floors at plumbing fixtures. All clean. No signs of mold in attic. There is no oder in attic. Next step is moisture meter in sheetrock above plumbing fixtures (pex plumbing in attic) maybe a crown molding nail penetrated a line. And check ac plenum. We have never had flies in the house and now we do.

    If its not one thing its another!
  7. mtrentw

    mtrentw Active Member Industry Professional Forum Leader

    On the ammonia smell, with recent cellulose insulation, may be temporary off-gassing. Some cellulose products use ammonium sulfate as opposed to borate for the fire retardant.

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