Okay Nigel, I'm in a cold climate zone here, so maybe I should plan on being able
to run a defrost cycle sometimes. So, perhaps I'll plan on controlling the 4-way valve.
I was just trying to learn how they work at this site:
Heat Pumps
First, I need to get the leak brazed. Once that's done, I should be able to
figure out how to test the unit, making sure it will meet my needs.
Hopefully, the T-Run/Test function will allow for a somewhat normal heating operation.
Just saw this informative video on youtube.
YouTube - Brazing with Nitrogen vs. Brazing without Nitrogen