2 weeks ago ,dryer ran but didnt get hot,found thermal cut off blown, the one that is on the top part of the heating element duct. got thermal cut off kit and replaced the bad part. as i was reading on another post i now understand that i should have replaced both, i didnt replace the one w red on it, #3390291. i also read about checking for the heater to be grounded ,i removed both wires and got basically 0 on the meter, is this possible the thread said it should be about 10 ohms, also,between the connector and the case i got open ,which is what i am supposed to have.

thanks for your help, I am still not sure on the testing of the heating element, my analog meter only has 2 settings, RX100, RX1K,do i need a meter with a RX1 setting in order to get a reading of 7 to 11 ohms

do i need a meter with a RX1 setting in order to get a reading of 7 to 11 ohms

No the meter you have should do, even if you do not have the resolution to get a 10 ohm reading.
You are basically looking for continuity or an open on the heating coil and thermostats.

When you check for a grounded element also visually check the coil, sometimes when it gets hot it can sag and touch the case then when it cools it will open again.

Here is the wiring diagram
http://www.servicematters.com/d...0Sheet%20-%203401725.pdf

Also check that all the internal seals are OK re: drum etc.
The unit sucks air over the heater and through the drum, it then blows it out the exhaust. The operating thermostat is on the blower so if the unit is sucking in room air somewhere the dryer will run hot and not regulated the temperature correctly. If you cannot find a cause for the heater's thermal fuse blowing then I would also replace the operating thermostat as odds are high that it is not regulating the temperature correctly.

Could be the operating thermostat's contacts are welded together.

Why do you have to replace both together if one is still good?

The lower thermostat opens around 250 degrees, then closes after a rather long cool down period, the upper thermal fuse blows at 350 degrees, so for "normal" conditions, it never sees 350 degrees. In the event of low airflow, or a fire, or defective lower limit thermostat, the upper thermal fuse will blow.
Most of the time, the lower limit thermostat just failed to open due to a trip temperature above 350 degrees, thus it must be replaced. They both come in a kit for these reasons.
In the event of nuisance repeat fuse blowing, I have put a bunch of limit thermostats in an oven, selected the one with a lower trip temperature and the problem was solved. In these cases, however, I never found the problem as the measured air flow and cycling thermostat temperature all where "normal". Suspect customer overloading, or the use of fabric softener sheets that clung to the back vent. I also suspected a batch of out of tolerance thermal fuses, but was unwilling to destructive test a bunch of them. Also, I have discovered erratic cycling thermostats, mostly the heated ones, and erratic, high turbulence venting.
In view of the above, anyone doing dryer repair must have a decent airflow meter or manometer and a accurate digital thermometer.