I am trying to install a new Noma programmable thermostat.
My problem is that the existing wires leading to the thermostat are, Red, White, White, Red.
Does anyone know how this should be wired?
I've tried a lot of different combinations, and nothing works at all?
Thanks

You have a non code wire color wiring going to your thermostat. You will have to sound out each wire and find where it goes.