Dryer heating element comes on sometimes and then shuts off.

SOURCE: Replacing Heater Element in Roper Dryer

before you replace the heater most common cause of heating failure is burn out of the thermal cut-out. (also called thermal fuse, overtemp cutout and probably half a dozen other names) These are a small screw on device on the exhaust duct, when exhaust air reaches too high a temperature, like a blockage, they fail before a fire.
examin the exhaust duct inside the dryer for devices that look like this or like this with wires connected to the terminals. there may be 2(hi lo), test with a ohmmeter -conductivity good, no conductivity replace.
there are only a few different kinds the local parts guy will have them all. take the dud one for him to match.

SOURCE: Dryer not heating...everything seems OK

Y'ou are zeroing in on your problem. Read the info below and hopefully you will have your answer:
If your dryer doesn't heat, check these:

Power from the house
Heating element
Thermal fuse
Wiring
Power from the house Check to see whether there's power getting to the dryer. Is it plugged in? Check for blown fuses or tripped circuit breakers--your dryer uses two fuses or circuit breakers. The dryer could tumble but not heat if only one of the two fuses is blown. If you have circuit breakers, one of the two circuit breakers can trip, even if the two for the dryer are connected.

Heating element Often a dryer heating element burns out, but doesn't trip the circuit breaker or blow a fuse. The heating element is simply a long coil of special wire. You can check it for continuity with an ohm meter. No continuity means the element is bad and you need to replace it--electric heating elements aren't repairable.

Thermal fuse On many dryers, there's a thermal fuse mounted to the exhaust duct inside the back cover panel. The fuse--which is about an inch long--is usually embedded in black resin and mounted in a white plastic housing. If the fuse has blown, you need to replace it. (You can't re-set it.)

Wiring A common problem is for the main wiring connection from the house, at the dryer, to burn and break its connection. Because the dryer can still tumble with partial power, the connection may be only partially defective. You may need to replace both the power cord to the dryer and the terminal block inside the dryer that the wire is attached to.

SOURCE: Dryer not heating...tumbles and blows OK - is 2 30 amp fuses enough

ELEMENT IS BAD NEED TO HAVE A SERVICE TECH REPLACE THE HEATING ELEMENT

Ned Halaweh

• 240 Answers
• Posted on Jul 08, 2009

SOURCE: newer kenmore dryer does not heat , element has continuity

Check the thermal cut-off located on the heating housing. check for continuity on that.

SOURCE: Whirlpool duet electric wil not heat

Remove 1 wire from the element . Your 220 V comes from ...110 motor , 110 control board . Check which wire is not getting 110 V , trace it and see which it comes from . That will tell you which one is defective .