I have an old house with an oil furnace and water heated baseboards and no AC.
My house had 5 zones, all controlled by manual thermostats.
I wanted programmable thermostats to save money.
I basically have a three wire zone valve system and NO-ONE seems to make a programmable thermostat.
After extensive research, I solved the problem
3 WIRE MOTOR CONTROL and 3 WIRE SOLENOID CONTROLLED VALVES
The Ritetemp 8022, 8030, and 8085 can be modified to be used on 3 wire systems. This involves adding a wire by soldering it to a point on the back of the thermostat as per the attached pictures and instructions.
To connect to the Ritetemp thermostat:
Connect the W to the thermostats W (heat on)
Connect the R to the thermostats RH (power)
Connect the 3rd wire to the thermostats new wire. (heat off) (use a wire nut to connect).
Connecting just the R wire to the W wire turns on your heat.
Connecting just the R wire to the 3rd wire turns off the heat.
Most thermostats do not have the necessary 3rd wire function. The Ritetemp has the function but it is not available on the back plate yet. So to use the function, a 9 inch wire must be added as per the attached pictures. Do not use a thick or stiff wire.
The RC to RH jumper may be removed. The FURN mode may not be used. For hot water heat, we recommend changing the swing from 3 to 1.
Now your Thermostat will work at the temperatures that you set
Linear Mode
