My wife and I recently purchased a home with a homemade outdoor wood stove and radiant heat tubes in the floor. I am curious about the amount of heat loss that is to be expected. My stove is approximately 70 ft from the house and my water heater side arm is an additional 60ft from where the PEX lines come into the house. I bring this up because I took the temp reading at the sidearm due to the fact that the lines are insulated and that was the easiest location to gain access. My heat loss from the stove to the side arm is about 15 degrees over roughly 130 ft. Half of which is underground. Is this normal?? Any help is appreciated.

I have a three-zone hydro system, connected to two air handlers and the hot water. The two air handlers are using Taco Sentry ZA024Q4A1 zone valves, and seem to work fine (they light up, turn properly, and fire the boiler). The water zone is using a Taco ESP075C2-1 09-01 valve. When the water tank calls for hot water, [B]the valve lights up and turns properly but does NOT fire the boiler[/B]. Eventually the water tank will show an error code stating it "hasn't been able to get to temperature for over an hour" (unless of course one of the other zones is firing, which is my current work-around until I call the plumber on Monday). We just bought the house a few months ago, so I'm new to the hydro game. Is anything I'm describing indicative of a specific problem (ie, bad Taco ESP)? Is there a simple way for me to test the ESP unit to make sure that's the problem? Thanks! PS: The zone failed two or three times since we moved in this past July; simply powering down the boiler via the boiler switch would automatically close the zone valve, and turning the switch back on would open it again and the boiler would fire. Only now does it seem to not be working at all, even when I try that trick.