North Dakota GeoComfort 4 Ton 11 Year Old Compressor Shorted to Ground - Repair or Replace

Discussion in 'Maintenance and Troubleshooting' started by geobc, Feb 5, 2021.

  1. geobc

    geobc New Member

    Hello all, I'm a new member here with a repair or replacement decision I'm looking for input on.

    I have an 11 year old GeoComfort 4 Ton Combination unit that the compressor went out on about 2 weeks ago - short to ground. The GeoComfort warranty was 10 years for the compressor so I'm SOL there. I have been trying to determine to repair or replace. My understanding is because of the way the compressor went out there is a high likely hood of acid in the system and that because this is a combination unit getting the acid completely removed from the system will be difficult if not impossible. I have gotten quotes for both repair the compressor and replace the system. Needless to say I'm very unhappy about the situation as I thought the initial investment would have lasted longer than 10 years!

    To repair will be approximately $3.7K with a 1 year compressor warranty and 30 labor warranty. Different dealers have stated concerns with repairing a combination unit compressor based on the way that it failed.

    The option to replace is a bit more interesting. The dealer is not recommending to replace with a Combo unit again (sounds like lessons learned over time) and is recommending repalcimng with a Water to Water w/ and hydronic air handler - GeoComfort 4 Ton unit. It would use my existing buffer tank. I understand there may be limitations to this during the time of the year when cooling/heating may both be desired (late spring/early fall). The replacement cost is ~$19K (after leaning on GC, was $20K+. This would come w/ a 10 year + 8 year compressor parts only warranty. With the current 26% tax credit, that brings it closer to $14K.

    I also have a quote for a GC and WF combo units which are around $15k and $17k but I'm not sure I want to go through this hassle again with a combination unit if they aren't built to last.

    For both GC options, there is an additional option of $1.2K to hook up a storage tank option for the DSH. The current combo unit had a DSH that was hooked up direct to a Marathon hot water heater, but no storage tank. Also, the DSH pump failed about 3-4 months prior as it got a cracked fitting and leaked water into the bottom of the unit but was caught within hours of occurrence but hasn't been fixed due to distance from dealer.

    Questions I'm looking for input on....

    1. Repair or Replace - reasons?
    2. If replace, Another combo unit or a water/water with air handler? Why?
    3. Is the DSH w/ a storage tank worth the extra cost?
    4. Any other options I should be looking at or investigating?

    Frankly, I have a sour taste in my mouth with GeoComfort right now based on the problems with the current one (compressor, DSH, previous board issues) and a lack of significant compensation for a replacement.
     
  2. ChrisJ

    ChrisJ Active Member Forum Leader

    Sorry to hear of this trouble.

    I had a combo unit that I had to replace after 6 years. I had to abandon the radiant floor heating. I put in a heat pump hot water heater for DHW. I spoke with Docjenser about the combo unit, we agreed that they are built on compromise, neither side of the unit (W to A or W to W) is great at doing it's job. Follow me?

    I would recommend replace with the water to water option....as long as the contractor has good experience doing your type of conversion.

    The high end fix is Waterfurnace 7 series and a separate water to water. If you have a big budget...
     
  3. SShaw

    SShaw Active Member Forum Leader

    The DSH option on my 4T Waterfurnace 7 series works great with a buffer tank. In the morning the water in the buffer is always at 130 deg. It drops during the day with HW use, but usually stays at 100 deg or more. That's in the winter. I'm not sure about the summer temperatures, as I just added the temp sensor to the buffer tank this winter.
     
  4. geobc

    geobc New Member

    Unfortunately the budget for this isn’t endless - meaning adding a w2w and a w2a. The conversion to w2w isn’t an issue for the contractor as it is remove the old and completely replace with new units.

    Why do you say the the combos are a comprise and neither side is doing a great job?
     
  5. ChrisJ

    ChrisJ Active Member Forum Leader

    Having 2 systems in one unit and having to switch between the 2 with a stop & start of the compressor. More circuitry to control it.

    Compared to a unit that is dedicated to one job....

    My combo was an odd brand (Hydro-Temp) It could heat water and air at the same time. If the radiant floor buffer tank was calling for reheat at the same time as the air heat was running, the LAT (leaving air temp) was reduced.

    Our experiences may be different with combo units, did you have a good experience other then the unfortunate compressor failure?
     
  6. geobc

    geobc New Member

    Yes this combo unit worked differently, it could only heat the air or water individually at one time. The calls were prioritized for the air first as the water was for basement slab.

    The other issues I had was a control board issue early on and I think the board got replaced if my memory is correct. The other issue was the cracked dsh pump fitting this fall that led to water leaking inside the cabinet. Overall not impressed with an 11 year life for the unit.

    If I’m going to go the replacement route I want something solid as the tax credits aren’t as good this time and I expect this equipment to last longer than 11 years. I’m unaware of the hydronic coil air handlers and if they’ve been used for a period of time and have been proven with geo systems?
     
  7. wing

    wing Member

    I have two Terra Therm air handlers hooked up to a 5 ton water to water heat pump and they work great. I particularly appreciate that the entire system then becomes modular and easy to monitor or troubleshoot versus a high priced, complicated, black box combination unit that requires a specialist to repair.

    My application is slightly different from yours as the main heat delivery to the house is via in floor radiant heat. The air handlers are for heating a section of the house that does not have radiant floor, or for cooling in the summer or as electrical resistance backup to the heat pump system.

    If you decide to go water to water then no need to plumb in a DSH. The output from your water to water can be connected directly to a specialized water heater with internal coils. This allows the entire heat pump output to be directed to heating water, much more efficient than the small percentage of heat pump capacity that can be generated by a generally troublesome DSH.

    Same problem here with daily requirement for both heating and cooling. Mine is during the summer months with high diurnal variations - heat needed in the morning and night, cooling during the days and early evening. I went with a separate buffer tanks for heat and for cool along with an array of zone valves to switch between tanks.
     
  8. geobc

    geobc New Member

    wing - that is part of what I like about w2w w/ an air handler - the simplicity vs the combo unit. If I decide to replace, that is likely what I will do. The costs is high and I'm wondering how far down the road a compressor repair would get me or do I "bite the bullet" while there is a little tax credit left.

    To add, the floor heat I have is only for the basement and is for comfort and provides a lower elec rate based as it is noted as storage heat. Otherwise, there are separate forced air zones for the 2 levels. So I could do a water to air and then add some sort of boiler but I think the costs/lost efficiency wouldn't be a smart choice.

    I wasn't aware of the water heater option w/ internal coils that you mentioned. Who manufactures this type of water heater? Is it used like a buffer tank with a DSH?

    I hadn't thought of or been provided the solution of 2 buffer tanks for heating/cooling demand. I already have a buffer tank for the existing radiant heat. It was stated on days that you needed both that the tank would need to go from hot to cold or vice versa to provide what was needed. I also figured if absolutely needed that the plenum in the air handler could be used for this but obviously again defeats the efficiency of geo. Can I ask your approximate location and how often/many days you believe you run into this situation?

    Is there a reason that you have 2 air handlers instead of 1 larger one?
     
    Last edited: Feb 6, 2021
  9. wing

    wing Member

    I have the 120 gallon Caleffi NAS20123 with electrical backup for hot water generation using a water to water heat pump. @docjenser , who posts here frequently, commented that a dual coil Stiebel Eltron would provide improved heat transfer. What I have works, the Stiebel unit would be better.

    The plumbing is a little different versus a conventional DSH where you generally circulate potable water through the DSH. These hot water heater heaters are based on heat exchanger coils located inside the hot water tank. That avoids the big pitfall with most DSH setups - crud from the water mains /water well clogs up the DSH piping.

    I am located in Eastern Oregon. It’s high desert country and I will alternate between heating / cooling depending on time of day from June through September.

    The reason for two air handlers was that this is a timber frame house with a third and fourth (tower) levels. It was easier / cheaper just to run insulated hPex tubing to a third floor hydronic air handler room versus extending bulky ductwork up and around the timber frame.

    From the description of your setup , you would have a water to water unit with load water directed to the hot water heater, air handler or basement hydronic tubing based on thermostat calls.

    Good luck on your geo journey.


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