we are having some issues with our geothermal and I was wondering if anyone here could provide some suggestions on troubleshooting. I have been 'lurking' on this site for awhile and it seems like there are alot of resources here. I decided to put in a geothermal but i am no means an expert and have really a fairly basic understanding of the system.

We built new home a year and a half ago. 2 story with unfinished basement. 4000 sqft finished. Attached 3 car garage. there is infloor heating in garage and basement from geo. we have 2 units, a 5 ton for main floor and H2O and 3 ton for upstairs. Have a closed loop system. last year during the winter our electric bill was about $400-450 per month. The highest was $520. Last year I kept the garage at about 16-18 C. We also keep the house pretty warm - 22C down and 21C upstairs (Have 3 young kids). This winter our bill in Nov was $450 and then in Dec, which really was quite mild it was $750! There have been no other changes in terms of appliances etc that should account for this. As well it is having trouble keeping the garage warmed. This year I actually turned the garage heat down to 12C and it is usually only 10 or 11. Last year if I set it at 18C, it was 18C. We had somebody from heating installer's company as well as a representative from the company that makes the actual heat pump out to check the system last week and it seems 'things are not working properly' They didnt give alot of details other than to say they want to set up a meeting with the builder. I managed to get some time alone with the rep from the geothermal company (he was a little reluctant to say too much in front of the heating installer guy) and i think his concern is the temperature of what is coming in from the wells is not warm enough (?). Again i am not an expert. He was quite surprised we did not do an open loop system. There are no restrictions against open loops where i live, i honestly dont know why we dont have an open loop, i was never asked which i wanted. The main problem as i understand is that the geothermal is running so much to heat the house it is having to use auxiliary (?electric back up) more often and is also not able to heat the water enough to warm the garage.

I am very concerned that there has been 50% rise in electric costs - this to me means something with geothermal is not working. Also the comments of the guy about not putting in open loop have me concerned that i may not have gotten the ideal system/advice.

Does anyone have thoughts on what might be wrong or what things should be done to find the problem?? Also would I have been better off with open loop system??

Sorry for the length of this. Thanks in advance for any help or suggestions.

A few questions:

Using the site http://www.degreedays.net/ determine your heating degree days this year versus last for the months in question.

How much has electricity increase in your area?
What models of geothermal furnaces do you have? What model of thermostat?
Do you have auxiliary electric heat? Is is set to turn on?
Try to measure your loop, Entering water Temp (EWT)(before the furnace) and Leaving Water Temp (LWT) (after the furnace)


That's a good place to start

Hi, thanks
Electricity has gone up about 10%, we can see the increase on our bill of the Kwhrs used for nov and especially dec. We have electric 'back-up' that is set to come on if less than 2 degrees below the set temperature. Our units are nordic geothermal, made by maritime geothermal. in the basement we have a TF-65, upstairs is AH-45. When the heating people were checking the system they measured something that from your description sounds like the EWT - whatever they were measuring it was only 31 and i think they thought it was supposed to be 40. I will have to do a little more reading to figure out the heating degree days!
Does this info help at all?

well from my very basic understanding of heating degree days - with a base temperature of 19 - we actually should have been requiring less energy to heat nov and dec of 2008 compared to 2007.
the numbers i calculated are nov 2007=517, nov 2008=502. Dec 2007=820, dec 2008=700. The Jan '09 bill should be a shocker the HDD are calculated at 920 which is far higher than any other month the last year and a half.

Even though ground source units are very efficient, a 4000 sq. ft. (Mcmansion? :p :p ) house will still cost a lot to heat in a cold climate.

Your gas or oil bill would probably be well over $400 excluding water and all electrical appliances (and gas costs much less than electricity) with a regular furnace.

Hopefully the house was built above minimum code with respect to insulation.

I suggest getting the refrigerant charge checked. (Also change filter, make sure all vents are open, etc.)

We just had a closed-loop system installed and are novices with this kind of heating.

But a few questions occur to me.

Are your wells deep enough to allow the water in your loop to regain its warmth from the earth?

Are your wellheads below the frost line?

In the horizontal runs between wellheads or from wellheads to your house, is the piping below the frost line?

If they aren't, is the piping insulated?

These are the kinds of questions that would occur to me if the heating specialist wanted to set up a meeting with the builder.