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Nordic/Maritime Geothermal system

Posted by Ricky64 (My Page) on
Mon, Jan 28, 13 at 19:01

We had 2 geothermal heat pumps installed in our new home in 2007 thinking that it would be more energy efficient and trying to do our part for "green energy" but its been a lot of trouble since then.

Manufacturer is Nordic/Maritime and units are EMW 65 and TF 65. EMW is used for radiant/floor heating whereas as TF unit is set up for heating water and forced air use.

In the last 6 years the compressor for EMW unit has been changed twice which should not be happening as these compressors have along life, yes the warranty is 5 years but they live much longer. The first compressor replacement was covered under warranty but the most recent one is not.

I am not sure if the problem is with installation or the machine itself. My thoughts go to installation as the first compressor burnt out in 2 years and the 2nd compressor burnt out in 3 years. Is there any way to figure out what seems to be the issue? Has anyone else had similair problems?

We have paid more than 5000 in repairs since 2007 till today.

Other frequent issues with the system have been as follows
1. air lock or what they tell me is that air bubble got in the pipes and they purge the system. They dont tell me how the bubble got into the closed loop system? This had happened almost once a year

2. It never starts with just setting the thermostat to heat and setting temperature, always have to call the installers in who almost purge theysytem everytime

3. We have back up propane boiler (Buderus) which is supposed to start when temperature gets too low and geothermal cannot keep up but it never does so

Any help in this matter is graetly appreciated. Thanks Rick

Follow-Up Postings:

RE: Nordic/Maritime Geothermal system

Where are you located? Have you spoken with Maritime? They're usually quite good!

Where is the air lock, in the ground loops or on the radiant in-floor side?

Are these 2 machines on separate ground loops? What type of flow centres are you using? Are the ground loops pressurized or not? If it is pressurized is there an expansion tank or any device to automatically eliminate air? What details can you provide regarding the ground heat exchanger(s)? Are the ground loops in series or parallel? Do you have any means of checking the flow rate (see link below)? Are the headers inside the mechanical room or buried underground (assuming the boreholes are configured in reverse return parallel)?

It sounds like it might be an installation problem. Is your installer CGC or otherwise accredited?

BTW: We have a Nordic DX-45 for almost 10 years now. It's never broken down.


Here is a link that might be useful: Blue-White Flow Meter

RE: Nordic/Maritime Geothermal system

We are in Northern Ontario.

I am in touch with maritime but they dont have a local installer. But the lake loops were put in by Maritime' distributer and the machines installed by CGC certfied installer.

Air lock develops on radiant in floor side

We are on a lake with the house 80 ft from water and 40 ft above lake level. Closed lake loops, with supply and return lines approx 40 ft (total 80 ft) using slinky coils in parallel loop, depth more than 8 ft but less than 10 ft. I think it has 10 lake loops. I have attached the details.

Right now the installer is saying that the lake loops are "matt loop" and that is the issue. Maritime is thinking that there could be an installation problem

Does the information that I provided so far help you? Please help me out. Thanks Rick

RE: Nordic/Maritime Geothermal system

Your situation may not be possible to diagnose over the web. You may require the services of a mechanical engineer to trouble shoot your problems, as they appear to be loop related on both sides of the heat pumps.

Regarding your pond loops, the top of the loop should be a minimum of 7 to 8 feet below the bottom of the ice cover on the lake. I also question the wisdom of using 3/4in pipe in loop lengths of 600 feet!

Regarding the in-floor loops, there should be automatic air elimination devices as well as an expansion tank within that part of the system. This would likely eliminate the air lock problems.

How well documented is your project, do you have an 'As Built Book' or CD including piping schematics with all valves, headers, circulators and other devices? This would apply to the loops on both sides of the HP. Were the 'Start-up' procedures and measurements documented? This would provide a 'baseline' so that any competent technician or engineer can come on site and understand what's going on - assuming it worked properly when commissioned.

I hope this is of some help. Please post back as progress is made or when you have additional information.

Good luck.


This post was edited by fsq4cw on Fri, Feb 1, 13 at 15:34

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