NO HEAT WHEN CLOTHES ARE ADDED

Check to see if vent hose is not restricted. If it goes up inside wall, it could have lint clogging it. Most dryers regulate heat with air flow. Wet clothes can restrict flow even more if vent is clogged or pinched. Air flow is crucial to heat cycle. If the vent is resrticted, heat will rise quickly, but not cool down fast enough to allow heat thermostat to cool down and turn on heating element again. It may seem hot inside dryer but if no air flow it will increase dry time or not dry them at all before timer shuts off. If vent goes up inside wall, buy a small chimney brush and try cleaning out vent from attic if you can.