I know I asked 6 months ago, thank you all who replied then. Checking in to see if anyone else has anything to report on their experience using a hydronic water to water heat pump (or DX to water). I am (slowly) getting my ducks in a row for converting my propane fired radiant floor heating system over to geo. Any failures of the Heat Pumps themselves? Particularly good performance or factory response? Thanks for any feedback! PBG

We've installed loops for Climatemaster, Heat Contoller, and Waterfurnace water-to-water heat pumps. All these heat pump have worked well and we haven't had any issues with them. The only current issue that I know of is that these water-to-water units will not allow you to apply for the 30% tax credit, at least as far as I've heard so far. Someone correct me if I'm wrong. Keep an eye on the Waterfurnace. These units based on nominal tonnage will outperform the competition. You'll just want to make sure you have a good loop field attached to the system.
Dan

We have seen great results in using EarthLinked DX heat pumps for water heating, both domestic and hydronic. The EarthLinked does qualify for the 30% tax credit. Typically, we see avg. COPs of 3.8-4.2 in the field with the EarthLinked when heating hydronic water and using a different brand (oversized) hydronic heat exchanger. If we use EarthLinked's heat exchangers, we typically see avg. COPs of 3.3-3.8 in the field. (this is here in Utah, with 50-55 deg. earth temp.)

thanks Dan and Clark, Dan - glad you're having good luck with the machines, we will have to figure out how to lick the tax credit problem... Clark, I am interested in looking at DX too, it does seem a simpler system then using an open loop (water well, pumps and dumps, etc.) What do you think is the upper safe limit for leaving water temp for radiant? Can you give any details on the heat exchanger required? thanks!

Anyone have experince with the Econar on demand hot water?
J