Before testing the flame sensor, unplug the clothes dryer or shut off
the power at the fuse box or breaker panel to avoid an electrical
shock hazard.
A gas dryer blows air through a
burner assembly to heat the air. The burner assembly consists
essentially of a gas valve, ignitor and in dryers that use a glow
type of ignitor, a flame sensor. If the flame sensor fails, the
ignitor may not go off and the gas flow will not start.
The easiest way to diagnose the
flame sensor is to observe the burner operation. Remove the small
access panel in front, select a high temperature setting and start
the dryer. Watch the burner assembly, shortly after starting the
dryer the ignitor should begin to glow. If it glows for several
seconds (up to 15 seconds) and then goes out, then the problem
is probably the solenoids (coils). If the ignitor glows and stays
on, then the problem is usually the flame sensor.
For testing purposes, the sensor
should show continuity at room temperature and no continuity when
it is heated by the ignitor.
