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.

SR

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

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

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.

SR

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