[mayzB]

I have a dual transformer electric ac with 5 wires. The old themostat was wired red wire to RH, white wire to W, yellow wire to Y, green wire to G, blue wire to RC. My new themostat doesn't have RC terminal.

R O B C Y1 E/W1 G W2 this is the terminal for new themostat. Putting the same color wires from old one to new (minus the blue wire), the heater works but ac won't turn on. Its not a heat pump unit so I know O and B aren't used, I tried the Blue (RC) wire in C terminal. Help

[Grady White]

Your new thermostat won't work. You have purchased a heat pump thermostat. If you have two transformers, you need a stat with both "R-" terminals.