oakguy,
i had similar overshoot issues w/ my forced air gas furnace. in my case, i appeared to suffer two problems: 1) the furnace appears to be oversized (5 ton) for my house (2200 sq ft house), and 2) the thermostat was located directly underneath the air return (which means there's a lot of airflow when the heat is running, and thus the temperature reading at the thermostat is a few degrees lower). interestingly, the overshoot problem seemed to become worse when i added the HAI themostat, compared to my old (dumb) Robertshaw digital thermostat in the same location. i can't tell whether my solutions will work for you, but this is what i did:
1. contacted HAI support about the missing 'heat anticipator' and 'heat EEC' settings. as i posted above, it was because my firmware was too old (1.02?) they agreed to let me send my thermostat in and update the firmware for me. when i got it back, the firmware had indeed been updated (to 1.03?), but this version was also too old to have these settings. when i called back, tech support explained that my hardware was not capable of accepting the newest (1.04?) firmware which was necessary for the missing settings. so they agreed sent me another (refurbished) thermostat (w/ updated firmware) in exchange for my existing one. the one they sent me in return still didn't have these missing settings (which are mentioned in their manuals, btw.. not sure why these early versions didn't have them available). after a few months of attempting to contact tech support by email and phone, i finally got a response from someone, and they did agree to send me a new rc-2000 that did have the right (1.04?) firmware. i adjusted the heat anticipator and heat EEC controls, and they did help somewhat, but the overshoot was still there and still a big problem.
2. i
wired up 4 hai
23a00 remote temp sensors to my RC-2000 thermostat. i installed the temp sensors in various locations throughout the house. the thermostat averages them together, and i disabled the use of the temp sensor that's built into the RC-2000. it has worked so well i have ended up changing the heat anticipator and EEC settings back to their default, and it works really well. i still need to play with the HVAC registers so they're properly balanced and the heating is more uniform, but the overshoot problem is basically gone.
i'm not sure whether the remote temp sensors will be as effective in the case of radiant heating, but it can't hurt to try it if the heat anticipator and heat EEC settings don't cut it. i would suggest getting in touch with the dealer/vendor you got the thermostat from and seeing if they will help you work w/ HAI to get the thermostat swapped out for one w/ the newest firmware. failing that, i'd say try contacting HAI support directly. as i found out, you may need to be persistent; they're all great people, but i think they get busy and maybe they aren't as organized as they should be.
good luck, and let us know what happens
