re: Gas Heater in a home..what has to be done to get it working

Just went through this.

Most likely it's an auto start without a true pilot like the old days.

There should be a junction box that's outside the unit (presumably the unit is in the attic). Cut the power. This prevents the lockout switch from messing you up when you go to turn it back on.

Set your thermostat to heat, but a cold temp.

Take the panel off the side of the unit and turn the switch on the gas control module to "on" and also make sure the gas valve is open.

Turn the power back on to the unit and turn the thermostat up to a temp higher than ambient to make the unit run. There will be a delay, but this is the basic set of steps.

If this doesn't work, you may need to cycle the power to the unit again. The lockout switch kept getting me the other day and it will cause a delay of some sort.

Hope this helps