[babzog]

Hey good folks!

I've got an older WaterFurnace PremierAT (model ATA040A100CLT) and it's (original) thermostat croaked. My contractor temporarily installed a Honeywell FocusPro t-stat but said it wasn't the right one (I need a 3H/2C one). I then went out and picked up a White-Rodgers 1F95-1277 (but what I really wanted was a VisionPro IAQ).

Well, my IAQ came today and I've installed it. Only problem is, the unit has a big red light on inthe upper right corner of the t-stat case and the screen keeps flashing code 40 (compressor should be on but it's not). It's set in Heat Pump mode. I have the L wire hooked up but the docs for the WaterFurnace seem to indicate that L is for faults only (whereas it seems to me the IAQ uses it for monitoring). I can turn on the compressor and aux heat by cranking the temp up so I'm not sure what I might have messed up in the install.

Willing to post whatever needs to be posted to help diagnose and resolve this. I'd love to keep the IAQ!

I should note... when I had the WR t-stat installed, it would briefly flash "call for service" when the unit switched off. Maybe I should just disconnect the L wire? But then, I'd have no fault reporting, correct? Can the IAQ be set to use L for faults only (no monitoring)?