I AM REPLACING A BAD TRANSFORMER IN MY FURNACE THE NEW ONE IS A LITTLE
DIFFERNET DESIGN. I HAVE CONNECTED THE BLACK 120V AND WHIT COMMON FROM
THE TRANSFORMER. MY PROBLEM IS WITH THE SECONDARY 24 VOLT WIRING
FROM THE TRANSFORMER IS GREEN AND RED FROM MY THERMOSTAT I HAVE RED
AND WHITE (NO AC) FROM THE GAS VALVE I HAVE RED AND YELLOW HOW DO I
CONNECT THE REMAINING WIRES.
THANKS FOR ANY HELP
Connect the Red and Green secondary wires the same way the secondary wires
were connected on the old transformer. It doesn't matter if the colors are
different or reversed, (although I've never seen red and green used)
Please turn of the caps next time.
Next time mark them as you take them off. Makes the job a lot easier. :)
The hot 24 side of the transformer goes to the thermostat. The neutral 24
side goes to the neutral side of the gas valve.
The return wire from the thermostat connects to the + side of the gas valve.
Colors don't matter. They should but sometimes don't. You have to read the
markings on the transformer and the valve.
If your system was wired with color coding in mind red = red and green yellow. They just used a two wire cable to the thermostat, both of those
wires are really red.
Colbyt is correct in his explanation of how the unit is wired, but- and
this is VERY important- there is at the very least, a limit switch that
must be in the circuit somewhere. Some break the transformer primary,
some the secondary, and some also have auxillary limts/rollout switches
that must be in the circuit. Your best bet would be to find the
schematic for your exact furnace and wire it according to that. Good
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