Digital t-stat question

[HomeGrown]

I did the digital t-stat mod, and it works great on the AC. Since I removed the propane furnace, I want to harness the t-stat output to control a 110v dedicated outlet for a couple of space heaters. Should be relatively easy to accomplish with a relay, BUT I can't seem to isolate the outputs for HEAT on the stat. I know the white wire is for heat, but relative to what other wire? I cycled the heat on & off (could hear the stat's relay clicking), but I found no change relative to any other terminal using my autoranging DMM. I expected to find a NO or NC change with heat on/off relative to the common terminal. There was no apparent activity from the white wire at all. This shouldn't be that complicated.

[RONSTAR911]

Get wiring diagram and manual for your model off the internet if you dont already have one, it should show where the relay contacts connect to witch color coded connections. you are right in thinking the contacts will close when heat is called for. typically one common wire feeds all the outputs so you may have to tap one of the wires going to the a/c relay to make the other closed contact for your heater relays. this is ok but be care full for feedback loops from one system to the other.
best of luck
Ron

[Kemosabi]

In the heating trade, red and white wires usually are the heating wires. Red (RH) is the common power and white (W) is the heating wire. A diagram from your stat manufacturer should confirm this.

GL

Kemo
Wildwood Lodge 392QBBS
2003 BMW K1200LT