Our dryer was bought new & the wife has been complaining for a couple months that she didn't think it was drying as well. Then this morning it won't dry at all. Flame unit comes on & heats for 5-10 seconds then shuts off for about 1-2 minutes then does the same thing again. Dryer can't get hot enough to dry anything that way. Upon inspection, I found the thermistor to be bad. It senses the air temp coming out of the drum. The electrical schematic in the rear panel of the dryer includes a resistance chart for the thermistor. Checking it with an ohm meter and a heat gun I found it to be open (shouldn't be) at room temp, then as I heated it it would show resistance of about 2.5 k-ohms, then as it cooled would increase to around 3.8 k-ohms then go open again. This means the dryer thinks it is either 120 degrees or nothing. Going to replace it tomorrow.