I took of my old Honeywell thermostat to replace it with a new setback thermostat. I found there are 5 wires total. 3 red, 1 white and 1 black. The white was on the "w" term. the black on the "b" term, 1 red on the "r" and the other two reds wires each connected to a "Tr" terminal. The Tr I'm pretty sure means transformer. The system is
24v, gas fired, hot water and about 50 years old.How would these wires translate to the new setback thermostats? I think the white goes to "w", Black I guess is not connected, but how about the three red wires? None of the new thermostats seem to make provisions for three wires. Do they go to Rh and Rc and ?
Thanks in advance.