I have a Colman central electric furnace model # 3400A818
The heat seemed to work fine until temp outside falls below 30 deg.
Took front panel off, blower works fine but coil elements only get slightly warm.
It also has a heat pump and on the thermostat an emergency heat switch,
When I tried to use it nothing happened.
I'm kind of girly, but with good instruction and or advice maybe I could fix it.
Don't have the money to hire out, also can't find manual that goes with it.
It's 16 degrees outside any help would be much appreciated.