Check the thermostat or the thermo switch. Either one might be faulty or there might be a loose wire.
Workin' on It was created in 2002.
If you get warm or hot air when in the a/c mode, you probably have little or no refrigerant in the system. Time to take it to an a/c guy to find out why it leaked out. The heater not working is a separate problem. SNAFU
No Keep Workin No Keep Workin
Workin' for a Livin' was created in 1981.
Workin' Overtime was created in 1988.
Workin' Band was created in 1988.
Workin' Together was created in 1970.
Workin' Them Angels was created in 2007.
We Workin' was created on 2009-11-03.
If there's no heat coming out, it isn't working properly. If you mean it's running, but not producing warm air, there are various reasons, but the heating coil may be out.
Workin' It Back was created on 1985-12-07.
Workin' at the Car Wash Blues was created in 1973.