Ac problem with the Honeywell Chronotherm III Therm
 

I just got a Chronotherm III to replace my old Honeywell dial therm.
When I installed it I get the -AC message. Witch in using the groups I
found out means no Ac power. What is wierd is when I turn off auto
and switch to the fan, it comes on.

Any Ideals, Any would help

THank You

Ac problem with the Honeywell Chronotherm III Therm
 

"David Ehrenreich" wrote in message
om...
I just got a Chronotherm III to replace my old Honeywell dial therm.
When I installed it I get the -AC message. Witch in using the groups I
found out means no Ac power. What is wierd is when I turn off auto
and switch to the fan, it comes on.

Any Ideals, Any would help


Easy enough.
You replaced a T87F that did not have a common lead. Ten to one, the wire
that is missing, or isnt hooked up at the thermostat, or the unit since it
wasnt needed, was the C line.
You still have power to the stat, the stat just has no way to know it.

The reason your fan comes on, is that like your old stat, the auto-on switch
is nothing but that...a switch. You are completing the circuit to the fan
relay.


THank You