Old 05-20-01, 02:27 PM
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I am trying to change my theromostat from a standard on/off
slide, to an electrical/timer one. My old one had 5 wires
connected. Green, Yellow, White, Red, and Blue. The new
thermostat states very clearly where the green, yellow, and
white go, but not the red and blue. My choice for
connections are g y w rh rc. I know what the g, y, and w
stand for, but not the rh and rc. I can connect all 5
wires and get HOT air to blow out, but not the nice COLD air
I had before I started this project. I have tried not connecting one of the blue or red, but then I get nothing.
I need help, it is 100+ out today ( I live in Az) and I
need the AC back. HELP!!
Old 05-20-01, 03:24 PM
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What you need is the markings on the terminals of the original thermostat, and what wire was on which. Sadly, installers often ignore the wire colors in the thermostat cable, and use their own "house" standard code. That's why the new thermostats usually come with the numbered and lettered code stickers to mark the wires as you take the old t-stat apart.

Assuming that your system is not a heat pump, most frequently, red goes to RH and blue goes to RC (red=heat, blue=cool).

Again, try to remember which one came off which terminal, and use the translation chart that's in the new t-stats instructions. There may also be a reset on the new thermostat that has to be set before it will function.


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