If you can persuede him to travel that far, I'd recommend Rick from Ashville Geothermal.

Followup on the air in the Waterfurnace. I installed an air trap with an automatic valve in the keep fill line and a check valve. I also installed Calleffi air separators on the top of both water loops. System has not needed pump out in two years. I would recommend air separators on all closed loop systems. My contractor fought me on installing this but it has eliminated the risk and cost. Parts cost less than 500 total.

But now three of the four water furnaces have required fan replacements. Now a total of 3 fans. The last fan cost me 957 dollars with the controller unit. This seems excessive to me. They are of course out of warranty. Not happy with my service company based on price gouging. If you work in the Charleston SC area let me know.