PDA

View Full Version : Honeywell RTH7400 wiring


digger72x
Jul 7, 2009, 02:19 PM
I want to replace an old non-programmable 2 wire thermostat with a Honeywell RTH7400 programmable one. What terminals do I put the two wires on in the Honeywell. My heater is just a propane wall unit without a blower. I just need to control when the heat is used. It is in our Church Sunday School Room and only used on Sundays. I will program it to come on about 0ne hour before Sunday School starts and go off at noon. The rest of the week it will be set at 54 degrees to prevent freezing in the winter months. The available terminals in the 7400 are: C, G, Y, W, RC, R, W2, Y2.

hixton
Jul 16, 2009, 07:11 PM
R and w

digger72x
Jul 17, 2009, 09:51 AM
Thank you!!

digger72x
Oct 16, 2009, 05:51 PM
OK Guys, the Honeywell RTH 7400 programmable thermostat for the church worked so well they want one in the office too. The old thermostat there has 4 wires RC, G, W, and Y. Do I just use the R and W this time too? If so, which two existing wires would I use? I'm guessing the old RC wire to the R and the old W to the W on the Honeywell. Can you help me again? Thanks in advance.

digger72x
Oct 20, 2009, 10:32 AM
More information. The unit I'm trying to hook up to the Honeywell has a fan. I'm assuming the extra two wires are for the fan operation. What connectors on the honeywell have control of the fan and I'm also assuming the burner uses the R and W connectors like the one without the fan used. Please help! Thank you.