How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask BillyHvac Your Own Question
BillyHvac, Journeyman HVAC Tech
Category: HVAC
Satisfied Customers: 22627
Experience:  Endorsed for unlimited heating, cooling, oil burners, boilers, refrigeration, hydronics
Type Your HVAC Question Here...
BillyHvac is online now
A new question is answered every 9 seconds

I am wiring a replacement ac air handler transformer but colors

This answer was rated:

I am wiring a replacement ac air handler transformer but colors seem backwards from original install. My original transformer had two prongs on one side labeled "LOAD" attached to a red and brown wire. The other side has 3 prongs and has a "230" to a black wire, "208" empty and "C" to a pair of yellow wires. My replacement has wires no prongs (totaline P201-3401). On the sticker it says


it seems like the blu/yel are opposite between the transformers where original seems to have been my HI V side with 3 prongs as two are labeled 230/208. My new one clearly labels blu/yel as secondary 24V. So which go to which when I install?



tie the 2 yellow wires to the transformer white

tie black wire to transformer orange

cap the transformer red and black wires separately and do not use.



24 - load


tie the red furnace wire to the blue transformer wire

tie the brown furnace wire to the yellow transformer wire.

BillyHvac and other HVAC Specialists are ready to help you