We are visiting my single sister in Charleston, SC from Grand Rapids, MI. She just bought a new home (with a heat pump) and needed some help in getting things done around the house. Being a handyman type, I packed my tools and headed south. Unfortunately I seem to have brought Michigan weather with me. They've had a slew of freezing or below freezing temps since I've been here, which complicates the matter I write qbout:
The first project was to replace the old thermostat with a new programmable one since she goes to business each day. The old thermostat was a Honeywell T874R1483 and the new is a Honeywell RTH7500D. I'm a retired telephone dude and am familiar with wiring, but to make sure, I went to the air handler circuit board and copied down the colors and terminals. Here's how my wiring went:
Air Handler Terminal Wire Color New Thermostat Terminal
C Brown C
O Orange O/B
Y Yellow Y
W2 White AUX. strapped to E
G Green G
Red is connected R
to another red at
air handler
-------------------------------------------------------------------------
Now here's the problem: With the day temp set for 68 and night to 58, the day comfort is fine, but during the night (and lower outside temps) we have cold air coming out of the vents. We had a HVAC tech come out and he said he found a loose wire on the strip heaters (I guess there's two of them?) He said he tested the heaters and they were okay. He also recharged the outside unit. Could you please verify my wiring and also tell me how I can test to see if the heat strips are functioning? I brought a multimeter with me and know how to use it.
I'd appreciate whatever help you can be. I've had a guilt trip since there wasn't a problem with the old thermostat, but then again, they hadn't had these lower temps before I came.
-Dick