HDPE MUST be used for anything buried, however, I would say that anything other than HDPE, butt fusion or socket fusion or commercially manufactured and approved headers in the ground heat exchanger circuit, at best, would be less than 'best practices'.

I would not like to see CPVC and glue as part of the ground heat exchanger - even within the envelope of a residential installation.

SR

SR

All of the burried lines are HDPE. The only place where CPVC was used is inside the house - manifold, valves, and lines to and from the heat pumps.

When I bought the system I knew very little about GT and even less about the various ways things could be plumbed. if I were doing it all over again today, i would have insisted on HDPE inside the house.

I just wanted to make sure that CPVC was OK, even if not the best, becuase I really don't want to yank all of my interior loop plumbing out. It looks like CPVC is rated to carry pure methanol so I shouild be OK with the plumbing as is.

As a safeguard, I recently added a pressure sensor that monitors the loop for low pressure. I have my loop pump control wired through this sensor so if the pressure drops below ~5 psi, the loop pump control and heat pumps will turn off. I added this in as a precaution to make sure that if a loop pipe breaks, I won't have hundreds of gallons of anti-freeze pumped into my house. The sensor won't catch a slow leak, but I check the pressure often and can deal with that if it occurs.

If anyone is considering GT, make sure that you do your research and ask the detailed questions before you give someone the contract. The small details on the manifold construction, loop pumps, loop pipes, fittings, and sensors to monitor the system are all important considerations along with the system cost and expected performance.

Sniffdog:

I think you're doing what's reasonable and called for in your situation. Reading you posts I know that you 'get it'.

I would suggest configuring your system, if possible, that when the pumps shut down due to low pressure that the system goes to emergency heat without the compressor so that you at least have heat when you're not home. You should also have a clear visual cue on your T-stat that this has happened so that you won't use more energy than necessary.

Should you have to swap out your headers, please see the link below. This is a 'Gold Standard' solution with a price to match. Sometimes you get what you pay for!

SR

Here is a link that might be useful: Geothermal Header

SR

Thanks for the data. That is what I wish my manifold looked like.