Steve, I'm not sure I'd expect a 50 degree ground water temp at 5-6 feet, especially as you are drawing heat from it at a high rate. However I'm not sure I like your temp diff. between EWT and LWT. Are you confident that these are good numbers? Can you get us the In and Out air temps? Make sure you are on 2nd stage with no aux. coil for this measurement.
Joe

Steve,

the reason your loop temp is low is the fact that you have been taking heat out of the ground. It is a common misconception that the ground can replenish the heat as fast as the heat pump can pull it out.

Joe is right, you should see a bigger spread between EWT and LWT. What brand and model is your heat pump? Can you find out the gpm through your loop?

I have a Florida Heat Pump ES049.
Today after a nice 3-4 day warm spell i have the following data:
First Stage Heat RAT 73.5 SAT 86.2 EWT 38.4 LWT 35.4 Flow 11.96 GPM
Second Stage Heat RAT 73.5 SAT 88.3 EWT 38.6 LWT 34.5 Flow 11.92 GPM

Steve, your system is doing great. Where do you live? How many feet of slinky pipe do you have?

Is there a performance chart in your manual?
J

Outside of Pittsburgh PA.
I have 4800 feet of slinky 6 trenches 5 ft wide 5 ft deep 800 ft of 1" pipe per trench.
I have dumped around $400 into flow meters and temperature probes to get this information because the frost on the refrigeration dryer inside the unit scared me insane.
You see my numbers and say the system is doing great. Can i get a refund? LOL. Does frost on the dryer worry you?

Frost is part of refrigeration process, but can sometimes indicate trouble.
J

How important is meeting the required 12 GPM?

Performance chart for my unit says i am not within the ranges:
First Stage Water Temp Change 4-5 deg F Air Temp Change 17-21 deg F
Second Stage Water Temp Change 5-6 deg F Air Temp Change 19-23 deg F

If your delta T was higher..like 15° instead of 4°, then you would need to increase the flow. Since your delta T is 4-5°, you don't need to worry about the flow.

You are a few degrees short on the air temp change. Increasing your loop flow will not help you. Is it keeping your house warm? How have your power bills been?

I am generally satisfied with the air handler side the frost scared me insane but if you say it is normally i want to know at what point i should be afraid of frost? My heating problems this year stared with a water to water unit Florida Heat Pump WP036. The compressor went in November and I have been dealing with Warrenty claims and in talking to FHP i was told that i wasnt getting proper flow to the unit. It requires 7 GPM and i am gettign 5.43 GPM. So that problem put the fear in me since that unit is a luxury and the air handler is a necessity.

Once i replaced the Compressor i found that both units ran fine independently. However when running at the same time the Water to Water Unit (WP036) would freeze up on the dryers and the unit would stop producing heat. The only thing that linked the two units was the Flow Center. This is why i was under the impression that low flow caused frost and frost caused the unit to stop producing heat.

sorry the 5.43 GPM was with the WP036 running independently.

so do you have one flow center and two heat pumps?

It sounds like your flow center can provide enough flow for one or the other but not both at the same time.

If this is the case,  you need more pump

Or separate flow centers

You don't seem quite up to snuff. Based on that, but... what GPM is it based on? Is the filter clean?
I'm ok with the gpm, it's important, but we can round it up. That's a lot of loop in the ground.
J

are your heat pumps in series or parallel with the flow center?