I have a 2 stage climatmaster tranquility 30, 5 ton house is about 3800 sq feet system is open loop, single well 440' 20 gpm Outdoor air temp has been 15-20 during the day, 5-10 at night pump pressure set to 60 pounds bleed off starts at 50 and shuts off at 51 ground water temp is around 52.8 Delta T set to 7 ***************** Pic 1 is of system running first thing in the morning after it had been running emerg heat all night. It was in stage 2 when I snapped this. Shortly after snapping this pic it settled into stage 1 and the LT1 started rising, then it reached 1 degree over set point and turned off. When it first started running the incoming water was 52.8. After this first run as you can see the incoming water is down to about 48. I have the bleed off valve set to turn on when the temp reaches 50 and turn off when it reaches 51. The problem is that the system is going to fire up again, but this next time it won't start with 52.8 degree water. The bleed off MAY get it up to 50 degrees by the next cycle, but when it starts from that point the LT1 gets down to below 30 and it locks out. Pic2 is a screen shot of one of the many lock out conditions. *************** Are there are other parameters I could tweak so that it doesn't reach lockout? I've had the installer check it out and he make sure the refrigerant is full. For example, could the delta T value help me here? -Thank you

What exactly is LT1 and LT2 measuring? I'm assuming this is somewhere in the refrigeration circuit? Is LT1 the coldest point and locks out at 30F to prevent freezing in the water loop?

If it is an open loop system, why is your entering water temperature dropping? Where are you dumping your discharge water?

After reading through your post several times, it sounds more like you have a standing column well and bleed off water (where?) when the water temperature drops to 50 degrees F? Is that correct? How many GPM are you bleeding off at 50F? All 20 GPM or just a portion? Where is it going? Have you verified the bleed off is actually dumping water somewhere other than back into your well?

You state your well is 440', but what is the static depth to the water level? Can it supply 20 GPM continuously? What is the diameter of your well?

Why are you running the well pump at 60 psi? That seems excessive and a waste of energy if you are just using this water for the heat pump. Is this water also being used for home use?

There have been some quirks with the PC boards on these units, have installer make sure you have latest revision. You might try a lower delta T as well.

Hi guys - sorry for the late reply. I thought this forum would email me when there was a post. I now see there is a checkbox I need to set.

Arkie6 - As I understand it Lt1 is a thermister that is measuring the temp of the refrigerant and it locks out to prevent the water from freezing. You are correct. It's a standing well with a bleed off that dumps into a separate trench. I don't know how much water it dumps. What was described to me was more like a half a gallon a minute or so. I don't have any way to measure it. I don't know what static depth to the water means. I was told the water was 30 feet from the top of the well if that's what you mean. The 60psi was an attempt to tweak one of the many variables to push more water through the system faster.

Joe & Arkie6 - My installer was just here. He added a ground to the board as there have been some cases in faulty readings due to house electricity spikes - but the regional rep doesn't think that's the problem. His suggestion was same as yours so we changed the Delta T from 7 down to 5. Please correct me if I'm wrong but as I understand it (was just told) this means that in an attempt to keep the outgoing water only 5 degrees less than the incoming water the valve will open wider to push more water through. If more comes through then it won't get as cold. If I understand that correctly, then I don't see how cranking up the water pressure to 60 lbs would make any difference. Seems like the delta T setting would be the relevant parameter and I should be ok to set the lbs back to 50. Yes?

It's going to get down to 3 tonight so we'll see how the new setting works! Thanks guys!

Posted By Baker on 27 Jan 2014 12:33 PM
... It's a standing well with a bleed off that dumps into a separate trench. I don't know how much water it dumps. What was described to me was more like a half a gallon a minute or so. I don't have any way to measure it....

If you are using 20 gpm for the heat pump and only bleeding off ~1/2 gpm, that means ~19.5 gpm of nearly ice cold water is dumping back into your well.  No wonder the entering water temperature is dropping.

Is the end of the bleed pipe open above ground or below grade?  I'm guessing it is below grade.  If it was above ground or you had a place above ground where there is a joint in the pipe, you could put a one gallon container under the outflow and time how long it took to fill up to get an estimate of your bleed-off flow.

Yeah - it's below ground. I really don't know the capacity. One of the installers told me it isn't too much. He then said "something like this" and proceeded to turn on the kitchen faucet at a pace that I'd guess is between 1/2 and 1 gallon/minute but that's just a guess. What do folks normally do? Should it be more of a well dump when the water gets down to a certain temp?

Thank again

Great news! Changing the Delta T from 7 to 5 made a difference. This morning I woke to a temp of 7 and there was no lockout! Hooray!! I'm attaching a screen shot of the stat values while at delta T of 5 vs the locked out delta T 7. Next I'm going to drop the psi back to 50. I really don't think that adds any value. Thanks again guys!

The geo needs GPM not PSI. Should be good anywhere above 30

Cool. I've dropped it back to 50. If I survive tonight, which is supposed to get down to 9 degrees, then I'll drop it back to 40. thx!