How to wire a thermostat

[darrellmak]

I am trying to connect my gas furnace/ac (which has 5 wires including a common wire) to a White-Rodgers programmable thermostat that does not have a connector for a common wire.

Will the thermostat work if I just leave the common wire unconnected?

THANKS!

[Ed Imeduc]

Info info helps what you have now and what the new one is. Could be the old one the common was for a system monitor Does the new tstat, runs on batteries????

ED ;)

[hvac4u]

if it has batteries, do not use common