That is a strange thought and made me look real close, good catch
sakrue... it looks like there's the default bare silver jumper back
behind there. It's strange that they'd connect heating and cooling power
together unless they both come from the sam...
In order to utilize a separate heating (rh) and cooling (rc) power
source you must use the learning thermostat. You are right that the
basic thermostat model just doesn't have enough terminals to do what you
need.