Hello all. My first post ,after reading here for a month or so.

I have a Econar 5ton hydronic GSHP, installed Nov07, running open loop.

The source coil froze and broke last fall, apparently due to a breif water flow problem, and the low pressure cutout failed to stop the compressor, because I discovered that that part of the control board has failed (if you pull one of the leads, it has no effect).This is Econar's only freeze protection, they used to use an extra sensor, but opted for one combined 35-60 psi. pressure switch on the suction side for open loop application.

Reading info on at least 4 other unit manufacturers, they all use some sort of other protection, thermistors, flow switch, etc.

My question is: Do any installers use extra site added freeze protection to guard against such problems or do you rely solely on the unit's devices?