Greg, My loop temperature during the winter dips down to the mid 30's during the winter months. As long as the solution does not freeze, the heat pump is able to extract some heat from it.

I have noticed with my system that a day or two at 0 or below, the heat needs to be augmented by the backup heat source. With this new NDZ038 heat pump I am not looking forward to days where the temperature will be below zero for days and sometimes a week at a time. But on the other hand, I am looking at how the new heat pump performs compared to the old ES036 WaterFurnace heat pump.

Have you had a chance to look at my monitoring page? The output loop temperature sensor is currently not working. I am going to replace it soon.

Does anyone know if there is a minimum water temperature that a heatpump typically needs for the incoming water in order to function properly?

I live on Lake Michigan. The incoming water is quite cold, and my geothermal unit has had trouble keeping up ever since it was installed (18 months ago)...at least whenever it is cold. I am wondering if the issue is that the incoming water (at 40F or colder) is just too cold.

Thanks

Last week, the temperature got down to near 0 degrees F for a couple days. After about 23 hours at this temperature the Electric Backup Heat kicked in because the second stage geothermal could not keep up with the demand. It is not even cold yet!

This is of great concern. The previous Premier unit would not call for Electric Backup Heat until the temperature was below zero for a couple days in a row.

Supposedly the problem may be in the timing for the third stage heat call. The air handler is a Bryant unit and has three settings for delay of the third stage heat, 30, 60, and 90 second. I have been told that another relay (variable delay selection more than 90 seconds) should be installed.

I am not really sure about this, trying to grasp the concept. If the second stage geothermal can not keep up with the load, the electric backup heat should kick in. The second stage heat stays on for at least an hour at times before the electric backup heat kicks in.

I think an email to Tech Support for Waterfurnace is in order.

Hi Stu,

Yes it did. I have been collecting ground temperature data for over a year now. The short term charting is working well. The long term, 365 day trend is not operating properly. I still need to resolve the charting issues. You can see the results on the following page: www.duanesworld.net

Did it work? Did you install it? I just had a GSHP installed and I'd like to measure the ground temp. Did your system work??

Well, my heat pump was replaced on Tuesday November 10th. The new heat pump is a Waterfurnace Envision NDZ038.

I chose option 2 to have the heat pump replaced since the new heat pump has a 10 year warranty.

The replacement of the old unit was fun to say the least. A difference between the old Premier unit and the new Envision unit is that the Desuperheater is now internal to the heat pump. That being said, the old desuperheater was removed.

All temperature sensors have been replaced on the heat pump including the runtime monitors and the power monitor. I am having trouble getting the desuperheater run time monitor to operate. After placing it on the new unit, it worked for about 8 minutes then stopped working. The return ground loop temperature sensor is also not yet working.

Those are the only two casualties so far.

I'm still not pleased with the cost of this fiasco. Geothermal HVAC units are supposed to be easier and less costly to maintain.

So far my payback has been pushed back from 7 years to about 10 years. Now, ask me if I would do this again. I am trying to keep a positive attitude but it is getting increasingly difficult. I won't even say "What else can happen."

Thursday afternoon someone was on site to check the Heat Pump problem. The WaterFurnace Heat Pump is 5 years old and the first thing found was that the Loop water pump was bad.

The pump was replaced but the FAULT problem still existed. The Heat Pump has a Bristol Compressor in it and apparently there has been a lot of problems with these compressors. I don't know why WaterFurnace has not had a recall on these systems.

Well, after the Tech talked with WaterFurnace I have two options.

Option 1 is that WaterFurnace will replace the Faulty Compressor with a new compressor. The replacement will cost me over $600 since WaterFurnace labor does not cover all the work required. On top of that, there is no warranty on the new replacement compressor.

Option 2 is to have the Premier Heat Pump replaced with a new Envision Heat Pump. Apparently WaterFurnace is providing a discount on the cost of the Heat Pump but it is still costing me over $2000 to replace.

The new pump is supposed to be arriving at the end of the week for installation on next Monday. We'll see.

Hi Nolan,

They were pissed because all I wanted them to do was to check the loop pressure. Which by the way was a little low and needed a slight addition. After this was checked and added, the tech did not understand the electronics of the installation and while on site 'troubleshooting' he made a few calls to his office and to WaterFurnace for their guidance. After a frustrating (for me) time, I finally told the tech enough and I wanted him to stop. He said "fifteen more minutes" and magically within that time the system was again operating properly. Not understanding the system or padding the time to make $300 for the call? I still wonder.

The filter is a permanent filter which I clean and keep clean. No other work was performed. No cleaning, nothing. For the regular service this firm charges $300 for there is a list of points which they check. I am not a goethermal hvac professional but I know enough about my system that most of what they do is unnecessary. That is why I wanted them out for the loop pressure check only.

Here is the Service Agreement in a nutshell (This service for $179.00 includes as visit in spring and one in fall):

1. Furnish tools and labor to perform HVAC maintenance service and checkup for the HVAC system.

2. Check condition of existing air filter.

3. Clean/Vacuum equipment housing, burners.

4. Lubricate all necessary parts.

5. Check electrical and low voltage controls.

6. Check all electrical connections located within equipment housing.

7. Check refrigerant pressure and charge. Add up to 1/2 lb. refrigerant if necessary (Conventional HVAC systems only).

8. Check blower and make adjustments as necessary.

9. Start up equipment and check temperature of the supply and return air.

10. Check temperature of supply/return loop water (geothermal hvac systems only).

11. Check operation of loop circulating pump(s).

12. Check freeze protection limit (geothermal hvac systems only).

13. Check Auxiliary electric heater operation (geothermal hvac systems only).

14. Check Desuperheater pump operation (geothermal hvac systems only).

I'm curious, what do they include for $300? I mean seriously, geothermal systems are virtually maintenance free. What are they charging you that much for? Changing the filter?

Hello Jill,

A couple questions first. What is the manufacturer or your Heat Pump / Geothermal Furnace? What area of the country are you located? How old is the Heat Pump?

Unfortunately I have found that installers are not very quick to respond to problems unless you can prove to them there is an issue. By the description of the two leds that are on your unit, it seems there is a mechanical problem.

Does your installer know that these leds are illuminated?

I would download the manual for the Heat Pump unit you have if you haven't done that already or if you have the paper manual in front of you. This will give an explanation of the led status.

Next, I would contact the Heat Pump manufacturer to find another qualified service organization in your area. Explain to them the problem you are having getting your system serviced by the installer, and let them know who the installer is so they can document the complaint. Most manufacturers are willing to work with home owners.

The key here is to get your system fixed as soon as possible.

Our geothermal is not working. Thermastat shows "fault" so back up electric heat kicks on. HVAC installer says we keep having electric gliches from our utitlity company (Ameren) and the geothermal system is so sensitive that it shuts off. So he has been telling me to shut off electricity at the eletrical panel and then turn it back on. Sometimes it works, but for the last week the thermastat has been at "fault". I am waiting for the installer to show up. It's been 6 days counting. I looked at the geothermal furnace indicator lights and there are 2 flasing red lights: Lo Pressure and Water Flow. Can anyone give us an idea?

That is a good point John. Thank you for the feedback.

How does that saying go, "Sometimes it is hard to see the forest through the trees"?

Its unfortunate that they had a hiccup, but the tech obviously saw something that caused concern.
One reason to keep from checking pressures is that the freon loop is a closed system, so every time you attach a set of gauges you are opening the system to contaminates (like air) and if the operating temperatures are right, there's really no need.

I am happy with the output of the main Ground Temperature Data page which shows the hourly temperatures and the current temperature reading meters from 1 foot to 11 foot depths.

I am still working on the other charts though, please be patient.

I am looking at looking an hourly average temperature for the One Day, One Week, One Month, and initially One Year charts. This new chart is still being developed and has not been placed on the pages yet.

I will update the post when I get closer to accomplishing this.

Earlier this summer, I accessed the ground temperature settings and placed some grout material in the tubing.

Previously, when I installed the sensors I left the cpvc tubing from the junction box ( at the 1 foot depth ) down to the temperature sensor hollow.

I have since come to the conclusion that the sensor might be effected by the air within the tube from the shallow depths.

As a result, earlier this summer I placed grout material in the hollow spaces between the tube and the wire to the sensor.

We shall see if this effects the temperature readings at the lower depths this winter. From last winter, I would have expected the temperature at depths of 10 and 11 feet to be more consistent and not cool off as much.

It is almost winter and almost time to put the humidifier to the test. I recently changed the humidistat adding an outdoor sensor to assist in the automation of the humidity setting. We will see in the next few months.

Robby,

Digital Thermostats have not been a topic of discussion on this site. My understanding is that most thermostats for Geothermal HVAC systems are Digital.

Please correct me if I am wrong. Digital versus Programmable thermostats should be discussed. I do not believe that you want to run a programmable thermostat with a Geothermal unit since the benefits of the system and basically the efficiency depend on longer run/cycle times.

You got me on this one. Im looking through your site trying to find some info on digital thermostats. Email me if you discussed this anywhere here.Thanks.

Technology is getting crazy!

http://www.san-antonio-air-conditioner-and-heating.com

Not good customer service. I would call around and find a contractor that is intrested in making you a life time customer. Had that company do the repair or corrction of existing installation. send the bill to the orginal installing company.