Indiana Troubleshooting American Standard Geothermal System

Discussion in 'Maintenance and Troubleshooting' started by Rus1981, Jan 12, 2018.

  1. Rus1981

    Rus1981 New Member

    Last edited: Jun 9, 2019
  2. arkie6

    arkie6 Active Member Forum Leader

    30+ deg F temperature rise across the air handler? Were the heat strips on when this was measured? If not, this often indicates too little air flow across the coil. You should see around 20 deg F rise across the coil with the heat pump in second stage. Was the fan speed set up correctly with the new unit? The fan should be set to move ~1600 CFM on stage 2 and this is often dip switch configurable on the control board. Some people don't like the "not hot" air coming out of heat pump registers, so the installer may intentionally set the fan speed to a lower value to make the air feel warmer, but this is not the most efficient way to operate the heat pump. Are your air filters clean? Are your return filters sized large enough to accommodate 1600 CFM without excessive pressure drop across them? Do you have zone dampers or balancing dampers in your duct work? If so, could one or more of them be closed off? Are you getting good air flow at all of your registers?

    That 11 deg F differential temp on the water side indicates insufficient water flow. Should be closer to 5 deg F differential. Are you sure that you are getting 10 gpm water flow through the unit? Can you measure the water flow coming out of the unit? A 5 gallon bucket and a stop watch works. Do you possibly have a clogged water supply filter/strainer?

    That 1 HP water pump running on a 50% duty cycle and cycling frequently is going to be an energy hog.
  3. waterpirate

    waterpirate Well-Known Member Industry Professional Forum Leader

    Agree with everything arkie said. For the cost of just the variable speed controller, you could replace your 1hp pump twice. The best money that can ever be spent is on envelope improvements. Insulation. I live in a turn of the century farm house. Initial manual J was botched badly. By making envelope improvements I have got the house to match the system, not the system match the house. I have no electric backup so when the system crashed before I burned wood. The effort of burning wood as aux. heat put money for envelope improvements on top of the list of expenditures.
  4. Rus1981

    Rus1981 New Member

    arkie6 - Thank you for your response. According to my thermostat, that was strictly in Heat Pump 2 mode with no strip heat. I opened all of the dampers in the system (one closes off upstairs, one closes off half of downstairs, one closes the other half) and did the tests again. In heat pump 2 mode, with the strip heat off at the electrical panel, I saw a rise of 38* F (64*/102*). In Heat Pump 1, I saw a rise of 33*F. My filter was replaced a couple of months ago and is an Aprilaire Whole House that is supposedly good for a year (I replace it every 6 months). As for the fan speed, I opened the lower cover and checked the DIP switches. It looks to me like it is set as follows: Recirculation - 800, Stage 1 - 1350, Stage 2 - 1550, Aux - 1575. Return air in this house has always been an issue because of the way the ducts were run almost 40 years ago when my dad bought the house and had it outfit for forced air. I think we are probably good on that, but I know that we don't have enough return air ducts upstairs (but we don't really have much of an option).

    As for water flow, I did exactly as you recommended, I used a 5 gallon bucket and a stopwatch and timed the fill time. It took almost exactly 30 seconds to fill the bucket. I checked the temps again, and they read IWT 57*F and LWT 48*F in Heat Pump 1. In Heat Pump 2 it was 55* and 46* respectively.

    With the cycling issue in mind, and the high cost of the variable speed set-up, should I be thinking of swapping out the 44 gallon pressure tank to at least one 86 so that the cycles are longer and fewer?

    Thanks again.
  5. Rus1981

    Rus1981 New Member

    waterpirate - Envelope improvements have been on the agenda for a long time, and since we moved here almost 6 years ago, I have replaced all of the single pane windows from the 1900s with dual pane, low-E/Argon windows and done as much insulating as is possible. All the exterior doors have been replaced, and new storm doors added. The process of insulating the attic seems so outrageously daunting that I keep putting it off. Maybe I'll just have to bite the bullet and get an energy audit done and have the attic hired out.

    I'll be honest, the property is 8 acres. It's the house where I grew up, and when my dad died my wife and I decided to buy it from my mom. Dad was sick for a lot longer than he led on, and I've found issues on every single building or system that needed to be repaired or risk losing the building entirely. I've been in triage mode since the beginning. Add in 2 kids and lives little troubles, and I've put insulating the attic below new roofs and broken pipes.

    Thank you again for the help.
  6. waterpirate

    waterpirate Well-Known Member Industry Professional Forum Leader

    No worries I and anyone else who buys the stewardship of a older property is in the same boat with you! I did not buy the family home but opted for one even older. IMHO they are worth the time and money so long as you enjoy the journey.
    In regard to your purchase of a larger tank, you can buy a additional 44 gallon tank and add it to your existing for a total of 86 gallons.
  7. warmbrus

    warmbrus New Member

    Hi, I am new to geothermals and not an expert. My issue is that I have replaced two heat exchangers and the copper pipe to the heat exchanger is very thin. I live in Kentucky and my system is open loop on a well (pump and dump). I have a Carrier unit which is made by ClimateMaster and I believe is same as the CllimateMaster Tranquility. The Carrier model is GT-PX 50YDV049KCK301. It is a 3 1/2 ton unit with scroll 2 stage compressor. The pressure switch on the well is set 30 psi to 50 psi. When the water pressure is near 50 psi it sounds like cavitation in the Taco 556 control valve. However, I am thinking my issue is particulates in the well water is eroding the piping and heat exchanger. Does anyone have info on external/indirect heat exchanger sizing information. The cure may also be a water filter if anyone has information on sizing a filter or knows who can help. Thanks.

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