Replacing mechanical thermostat with programmable
I'm looking for help from labman or any experienced HVAC person... here goes...
I recently purchased 2 Honeywell Focus Pro 6000 programmable model TH6110D1005 thermostats (I have 2 zone heating). I'm a replacing a mechanical honeywell dial mercury thermostats (Probably about 20 years old or so). When I took the cover off the old thermostat, I noticed there were 4 different wires. There was a red, black, green and yellow. The red and back wires were connected together to the R terminal on the thermostat and the green and yellow wires are connected together to the W terminal. There is a Y terminal on the thermostat, but no wires connected to it. It is a heat only system and I do not believe that there is a fan. I also went to the boiler to look at the configuration and there are two boxes (I assume one for each zone) and each box has two terminals named T and each one has two wires connected to them (Red and Black together and green and yellow together)
The Focus Pro has G W C Y R Rc slots. There is a jumper between the R and Rc slots. I have hot water baseboard heating system with a boiler. It is heat only. I got confused with the red and black wires and green and yellow wires connected together. Any idea on how to hook up the new thermostat with that configuration. Do I leave the jumper in the R and Rc or do I remove it?
My first reaction was to connect the new tstat the same way as the old one with the red and black in the R terminal and green and yellow in the W terminal and leave the jumper in. But I am hesitant to do that because I don't want to scew anything up and have to get someone in to fix my error.
The instructions for the focus pro say to have a professional install this thermostat, but I also looked at the RTH6300B thermostat that say a DIYer can install it? What is the difference and should I return the Focus Pro and get the RTH6300B thermostat?
Any help would be greatly appreciated.
Thanks so much in advance,
Scott