I have a samsung gas dryer that heats minimally. I have torn it down and tested the following parts
Sensors:
Thermistor at 48F garage temperature reads 17 - 18k resistance. not sure if this value is acceptable.
Dryer Thermostat continuity is good
Dryer Radiant senor assembly continuity is good
High limit thermostat continutiy is good
Components:
Igniter gets bright hot
Coils at 48F reading ok 3 prong readings ~1500 ( outside and middle) and ~600 ( outside to Outside)
Observation: when the dryer turns on the drums spins freely. 10 seconds later I hear the first click at which point the igniter starts to heat up. 5-7 seconds later gas valve opens and there is ignition. At this point the ignition stays for 5-7 seconds and gas gets shut off. I read on this forum that the coil may function when they are cold but once they warm they could malfunction.
You’ve got either a weak hi-limit thermostat AP4201898, a weak flame sensor AP4201717, or a bad valve AP4203162.
Get to where you have access the hi-limit thermostat on the heater assembly, run the unit and wait for it to quit heating. Once it stop, unplug the dryer, disconnect the wires from the thermostat, and take a continuity reading across the terminals on the thermostat. If it is open then the thermostat is weak.
If the hi-limit is good then you’re down to the flame sensor or valve. The flame sensor usually opens about 7-15 seconds after ignition, so I’d probably replace that before the valve if it is opening 5-7 seconds after ignition.