20 Year old Water Furnace Premier AT compressor out - Time to replace?

[Jerry_NJ]

My 20 year old WF two speed geothermal heat pump went into a fault condition a couple of days ago. A reset didn't fix the problem The indications I have show "Low Pressure" problem, likely a refrigerant problem. The service tech will be out tomorrow morning to take a look. I am on resistive emergency heat, wow what the electric meter spin.

It may be time to replace the complete HP (not ground loop). The WF Synergy 3D looks to have a "plug and play" in that the loop and electric supporting the existing HP will fit smaller unit nicely - my have a 3 ton unit..and think the Synergy 2 ton heating (3 ton cooling) will handle my house and is about 20% more efficient than my old Premier AT.

The reason I like th smaller unit is my 20 experience tells me the existing unit is bigger than needed, designed to support heating needs at 0 degrees outside. We have that about 2 nights in 10 years and it would be fine to have to cut in the first stage of resistive aux heat on those rare occasions and the smaller unit would work better on cooling - ie. run more and at more efficiency which removes more humidity the main grip in NJ summer amazon days.

My thinking is the compressor on my 20 year old unit could go at any time, maybe it did, but I think not at this moment as after a reset it would run for a couple of minutes before the controller took it off line. The compressor sounded smooth, so at least the bearings are still in there and rolling.

 

[woodgeek]

Even if its a leak, and that that is fixable, you will have to find a matching replacement refrigerant....presumably R-22??

I bet you can find some recycled R-22 for a price. Perhaps you will get 10 more years out of it.

 

[woodgeek]

The reason I like the smaller unit is my 20 experience tells me the existing unit is bigger than needed, designed to support heating needs at 0 degrees outside. We have that about 2 nights in 10 years and it would be fine to have to cut in the first stage of resistive aux heat on those rare occasions and the smaller unit would work better on cooling - ie. run more and at more efficiency which removes more humidity the main grip in NJ summer amazon days.

The step down makes sense...but going from 3 to 2 is a big move (if the specs say it is really a 1/3rd cut). If your old balance point was 0°F, your new one would be 70°F - (0.67*70°F) = 23°F. If I assume we have the same climate, when my balance point was ~23°F then aux was ~5-7% of my BTU usage. IF you are getting COP=4, then that 5-7% of BTUs would increase your bill 20-30% relative to the 3 ton system. This could wipe out the savings from your 20% more eff system.

If your balance was really below 0°F, or if you have made some improvements since that data, you could be ok, otherwise I would compute the relative 10 year costs (or whatever time period) of the 3 ton replacement (or even a 2.5) versus the 2 and 20% higher operating cost.

If you are saying the aux only came on a couple times when the temp hit 0°F, the balance point could be a little higher. Houses (mostly foundations I think) have some inertia, if the temp drops suddenly and stays there, I always use 5-10% more BTUs the second day relative to the first.

 

[Jerry_NJ]

Thanks for the views.

The dealer arrived today to repair my existing unit. He gets at least AAA rating: Response, Knowledge, and Cost. Add another "A" for having the parts and all equipment needed on his truck. The whole visit took about an hour and that was with at least 15 minutes being added by my questions and talking about fishing. Turns out he knows my neighborhood as he comes their to fly fish the South Branch, about 1/4 mile (down hill thank God) from my house. Oh yes, my little Terrier (Westie) added a few minutes with his warnings and inspection of all actions.

I suggested from the readout on the WF unit refrigerant might be the problem...he said could be electrical. I watched him open the correct doors without any reference to documents and said: Yes, the starter capacitor is blown. He replaced the capacitor and an associated relay and recharged the ground loop saying it was critically low, but some leakage is to be expected. He asked when was it last charged, I said about 3 years ago...the message is GET ROUTINE MAINTENANCE even on a geo-hp. Watching it takes a couple of pieces of special equipment to add antifreeze/liquid to the ground loop, not a DiY in my book. He also agreed the loop being low on liquid may have contributed to the failure.

The system is up and running and at specs.

He confirmed parts are scarce to non-existent on this unit, he can not get a new compressor if one is needed. While this repair was under $500, the past two repairs were each well over $1,000 each.

He said after rebates a System 5, 4 ton could be installed for around $10,000. Sounds good to me, and this price would reuse the existing ground loop and pumps (both pumps were replaced two years ago) and the existing wiring. He said major sheet metal work would be needed as the newer units have larger heat exchangers to gain in efficiency. His rough estimate included sheet metal and I assume removal of old equipment.

This repair man is a owner/operator, often the best we can get and is at the core of the American Private Enterprise high quality and value... not government run/screwed-up beyond what government does already with regulations and taxes.

I had some doubts about WF, and still do, but this dealer reestablished my faith in one of their dealer. He is a senior, but may be working for a few more years, he has installed Premiere AT WF HPs in the mid-late 1990s. He said my model is older than (mine is a series A, he installed C and D series units in his early years) - but I felt really optimistic (and justified it turns out) as I learned who had arrived on my cold doorstep to fix my HP.

He said my choice of a Synergy 3D was not the best, saying the Synergy is designed to deliver hot water heat and if one uses forced air for heating the System 5 is the best, lower cost, system. This was the reference for the $10K rough estimate. I'll check this out and I may upgrade next fall to a new System 5. I want to get a few hours of use out of my just finished repair. He said as far as my existing unit is concerned it could last for several more years but the high cost or repair and lack of parts support will require it be replaced.

Interesting too he recommends the two stage Scroll compressor, not the variable single speed (think I have it right the single speed varies how going to "Stage II" by varying the pumping load, not changing speeds, no stop-start). He is not yet convinced the newer design will hold up, time will tell. Hey, my two speed is still (cross my fingers) switching after 20 years on the job.

If someone in Northern Central NJ (Flemington North) needs a WF dealer who is a true expert, let me know. I had mentioned my feeling of a loss when the dealer who installed my unit retired, this new contact knew that dealer well and had high respect for his work/person.

I feel like I got an early Christmas Present on this repair,

Merry Christmas to all.

 

[sloeffle]

I have had the Series 5 Envision furnace for about 3 years now and have had no issues so far. Knock on wood. It was the top of the line model until the 7 Series came out in the last year or two. I did have my loop pressures checked every 6 months until my HVAC guy went out of business. They seemed to remain stable after the first full year of running it. I need to get them checked out in the spring time again. Luckily their are some Waterfurnace dealers in the area that can work on it.

What are you using for antifreeze in your loop ?

Scott

 

[Jerry_NJ]

Thanks for the experience on the Series 5, my new (the one who installed my existing unit 20 years ago has retired) WF dealer said he'd recommend the Series 5 as he considers the the new variable speed compressor needs more field experience before he is sold on as an added value. The two speed compressor I have, which does a lot of switching back and forth, trying to run in Stage I COP = 4 as much as possible, is still running (cross my fingers - I'd like to install a new Series 5 in the spring or fall when I don't need the HP). My measurements of the BTU delivery and the power consumed continues to verify the 20 year old is still meeting efficiency specs. The dealer agreed and used the same measure I use, the temperature rise across the plenum. I got a calibration my measuring the temperature rise with just the 4.8 KWatt Aux first stage running, and found it to be about 10 degrees with the fan on 1400 cfpm (top speed). The stage II hp only gives me a bit over 20 degrees, or the same heat as 9.6 Kwatt (33KBTU) and uses about 2.8 KWatts to do it. 9.6/2.8 says a COP of 3.4, better than the specs for 32 degree loop, but the loop was much warmer than 32 degrees, almost always is. The only reason to replace it is fear of end-of-life catching me in a bad negotiating position (cold or hot weather and I need the new HP NOW). As I think I said above it looks like I can get a 4 ton Series 5 installed for about$10K after tax rebate, using my existing ground loop including the pumps which were replaced about 2 ye ar ago. Even if a replacement compressor and heat exchanger were available (they are not) it would likely cost around $5K to replace them, my wild guess based on the cost of two other repairs. Those repairs were done by a Geopro I didn't call back, I had some issues with him, and he is no longer a Geopro anyway - and I've learned that is awarded by WF to dealer who sell a lot of new equipment, not necessarily those who get rave reviews for repairs.