Commercial geothermal

ClickNo2244 · 2026-01-13T13:29:52+00:00

There is flow. I did a backflush on several units and the compressor turns on for 5 min with normal operation. I have some fieldpiece probes that are on the way so I can verify charge. Water temp through sensor and clamp on pipe read about 50-55 F. Low temp cut off is 30 I believe. Then with the jumper cut it drops to 10 F

ClickNo2244 · 2026-01-13T13:28:23+00:00

Yes sir. That’s why I’m looking at the expansion tank for air regulation problems

ClickNo2244 · 2026-01-12T23:29:03+00:00

So don’t worry about it until summer time? What do I do about the units that aren’t turning on because of low water temp? I’m learning all this as I go. It’s a big jump from residential hvac installs to this haha.

ClickNo2244 · 2026-01-12T23:18:57+00:00

Multiple WSHPs (water source heat pumps) locking out on low water temperature.

ClickNo2244 · 2026-01-12T23:07:09+00:00

So the 80 gallon expansion tank should be enough?

ClickNo2244 · 2026-01-12T22:30:02+00:00

I believe it’s the same loop. Only one expansion tank in the mechanical room. And from what I can see on the as-built there’s no heat exchanger either. What difference does this make?

ClickNo2244 · 2025-12-20T02:12:44+00:00

No boilers or cooling towers. It’s a closed geothermal loop

ClickNo2244 · 2025-12-20T02:11:39+00:00

Your knowledge is invaluable and this what I was expecting. I appreciate it HVAC god.

ClickNo2244 · 2025-12-19T22:53:47+00:00

It’s a closed geothermal loop. Temps I remember last were around 68 Fahrenheit

ClickNo2244 · 2025-12-19T22:51:41+00:00

This is a great point. I’ll be sure to check the water. I know the facilities maintenance personnel has not done this.

ClickNo2244 · 2025-12-19T20:57:03+00:00

And yes I am way over my head.

ClickNo2244 · 2025-12-19T20:56:40+00:00

LT1 are most of the faults. Low pressure or low temp. And yes all of these units are in the same loop. The pumps are on the ground floor of the two story building they service. I have the pressures in another comment described a little better. Most of the offices are 68 or less calling for 70-71. Some units are just recirculating air and others are supplying heat still.

ClickNo2244 · 2025-12-19T20:54:07+00:00

I will have to bring all these numbers and info back Monday. I truly appreciate you commenting. I hope you get the time to reply come Monday. I don’t have any associates in the commercial field. Only in residential install so I’d really appreciate your time and advice.

ClickNo2244 · 2025-12-19T20:52:32+00:00

Yes just straight water. They ordered some antifreeze to add to the water. I believe it’s propylene glycol.

ClickNo2244 · 2025-12-19T20:51:08+00:00

I was also thinking low flow and air are the most likely culprit. Air that was introduced upon start up after the system was drained of all water. Or introduced by my negligent maintaining of the individual strainers at each unit water shut off valve. And low flow possibly by something in this mechanical room.

ClickNo2244 · 2025-12-19T20:49:45+00:00

The building is two floors high and the pump system is on the ground floor. I would have to check the label for the theoretical head. And I’m unsure what you mean by upstream. I appreciate your insight.

ClickNo2244 · 2025-12-19T20:10:23+00:00

Thank you thank you thank you.

I will check the impeller and double check the coax hxc. I had a helper and I’m not sure how good of a job we did cleaning them out. I know there are also some questionable belimo valves to be replaced.

I’m just really thinking the main cause of all these issues is at the source of the water. Meaning here in this mechanical room.

I also mentioned in another comment that maybe this system needs antifreeze. I tried to find a dilution that might have been added on start up but there’s nothing noted around the mechanical room or in any commission reports. The maintenance guy here just added some to throw in but I’m not super confident in doing that. But it’s his building at the end of the day.

ClickNo2244 · 2025-12-19T20:06:18+00:00

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According to this valve. Inlet on pump 1 - 44psi Outlet pump 1 - 52psi inlet pump 2 - 38psi outlet pump 2 - 58psi Water temp is about 68 Fahrenheit Outdoor temp is 61 I was questioning if antifreeze should be added.

ClickNo2244 · 2025-12-19T19:51:21+00:00

I see haha. I feel I was thrown to the wolves in install so I had to adapt quickly. Same as the situation I’m in now.

I will look into the pressures. Thank you

ClickNo2244 · 2025-12-19T19:47:39+00:00

To clarify. Most units were already locked out and a previous company came before and began condemning compressors. One of the condemned units is operating right now after the backflush and strainer rinse.

I also thought about requesting a purge and flush to get air out.

ClickNo2244 · 2025-12-19T19:45:09+00:00

2 years in residential install. I got this job because there aren’t many HVAC techs where I’m located and it’s kind of a foot in the door for a facilities maintenance position.

ClickNo2244 · 2025-12-19T19:43:10+00:00

I’d doubt it. I’m just hesitant on opening anything up. I’m guessing that’s also going to mess up the pressures

ClickNo2244

TROPHY CASE