Check the fuel filter on the units as well as the inlet and outlet filters on the back of the motor.
Watch the nose cone and see if the end starts to loose the glowing orange color before it quits. If the unit slowly looses the color then you have a fuel problem but if the unit just quits at full heat then you could have a electrical problem.
Typically the spark plugs on these heaters don't go bad.
Answers & Comments
Check the fuel filter on the units as well as the inlet and outlet filters on the back of the motor.
Watch the nose cone and see if the end starts to loose the glowing orange color before it quits.
If the unit slowly looses the color then you have a fuel problem but if the unit just quits at full heat then you could have a electrical problem.
Typically the spark plugs on these heaters don't go bad.