Wait for the unit to cool if it has been in use.
Test furnace gas valve.
Some gas valves cannot be checked with an ohmm.
Take out the bolts in the service panel on the side of the furnace using a nut driver.
Pull the wires off.
This one covers a simple way to find out if the gas valve is being energized on the newer gas furnaces.
How to check the furnace gas valve with a multimeter step 1.
This one shows how to do a voltmeter check of the gas valve.
Turn off the furnace at the wall control.
Locate the gas valve.
Sweep out any hair lint and foreign debris with a feather duster.
This video is part of the heating and cooling series.
Have an assistant plug in the appliance and turn on the gas feed valve.
I will be checking various gas valves to see if you can check the continuity of the solenoid with an ohmmeter.