i have no heat

i have no heat the blower works and the defrost works it just doesn't blow heat. I've been told that it could be the thremostat or the hearter coil. just needs some heads up on what to do next and how to go about it. just don't want to be cold this winter.

Is the thermostat working or present at all? Are both heater hoses hot? If one isn't you might have a clogged heater core. If that is the case, sometimes you can unclog them by disconnecting the heater hoses and back flushing the core with a garden hose. If both hoses are hot, the blend door under the dash may be stuck and not allowing the air to circulate past the heater core. The vacuum line to the door motor might be leaking and not allowing sufficient vacuum to operate the door.