mdesmarais
Active Member
I had an issue this week with my Omnistat. . . when it would call for AC, the furnace and compressor would kick on, and the thermostat would reset, and it would get confused about what state it was in, and stop calling for cool. I also recalled that i had seen it reset a few times during the winter heating season. When I did a little googling, I found out that HAI makes a couple of specific products to address this exact issue- which occurs because the 'stat is powered parasitically off the heat and cool lines, which glitch when the relays on the furnace control board switch.
Well, I didn't really want to wait to get in one of these pieces (power supply or isolation module), so I went looking for a way to wire in my own 24VAC supply. . and found this page, the last post of which turned out to solve my problem perfectly- I stole the FAN wire, since there were only four wires, and we never run the fan separately, and hooked it up to the C terminal on both ends, and presto- no more resetting thermostat, and lots of nice cool air. Just thought I would share it here in case someone else runs into the same issue.
Markd
Well, I didn't really want to wait to get in one of these pieces (power supply or isolation module), so I went looking for a way to wire in my own 24VAC supply. . and found this page, the last post of which turned out to solve my problem perfectly- I stole the FAN wire, since there were only four wires, and we never run the fan separately, and hooked it up to the C terminal on both ends, and presto- no more resetting thermostat, and lots of nice cool air. Just thought I would share it here in case someone else runs into the same issue.
Markd
