We are in the process of selecting a geothermal system and have proposals for Waterfurnace 5 and 7 series as well as Comfort-Aire HZ Series. I’ve heard and read a lot about the Waterfurnace and benefits of the 7 series, but I was surprised by how good the Comfort-Aire HZ and HZS products looked. While the compressor is two speed like the WF 5 (not fully variable like the WF 7), both the circulation pump and blowers are continuously variable. The heating and cooling output and EER and COPs at full capacity are as good or better for same tonage (4 ton) and the warranty is 12 years (vs. 10). Anyone have any experience or advice on the Comfort-Aire HZ and HZS? What am I missing vs. WF 5 series and even 7 series? Price is meaningfully less.

I would suggest making sure the warrantee covers you through the payback period of the installation.

I have put geo in two of my houses and and both have had equipment failures that required compressor replacements. This totally ruined the payback and wont ever do geo again.

Both houses also had the option to heat with either Natural Gas or Geo because I like redundancy and in testing Naturel gas was 80% of the geo cost to run, so no savings.