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Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 6022
Experience:  Retired HVAC/ Electrical & Boiler contractor. Industrial
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I have an old Marley D22 thermostat controlling 2 6 foot

Customer Question

i have an old Marley D22 thermostat controlling 2 6 foot electrical baseboard heaters. The old thermostat has 2 red wires and 2 black wires. I have 3 sets of black/white wires with ground coming from the electrical box to the old thermostat. I am replacing the old thermostat with a Honeywell RLV4305 thermostat with 2 black wires. From the box I have one set of wires with black going to 1 thermostat red and the white going to the other thermostat red. Then the other two set of wires from the box, both whites going to 1 thermostat black and the 2 black going to the other thermostat black. How do I wire the new Honeywell with only 2 black wires.
Submitted: 1 year ago.
Category: HVAC
Expert:  gotoman for ac replied 1 year ago.

You have two wires coming from load. Take one wire and connect to black on thermostat,, The other black from thermostat connect to second power wire, The thermostat will make and brak on side of power going to load. Do same on other thermostat. Russ

Customer: replied 1 year ago.
i forgot to mention that the old wiring where box white and black are going to thermostat reds, the white has a black jumper going to red and the black has a white jumper going to red. I have a phone picture if that helps explain the wiring schematic any better, I just don't know how to send it to you.
Expert:  gotoman for ac replied 1 year ago.

Can you take photo and attach. Russ