A/C works fine but when I run the heat it just blows regular air. My wire setup is RC, Y, G, W, C.
I bought an Amazon thermostat today and the Heat and AC work fine (same wire setup). Suggestions? Maybe a faulty unit? I have a single stage electric furnace.
You might have a faulty thermostat. This seems very likely if another different thermostat works fine using the same wires. When the thermostat calls for heat, it is really just switching power from Rc to W1 and G. It sounds like your thermostat is not having trouble switching to G, but might be having issues switching on W1. Does it work when you run it in test mode?