white knight, is it the element?

Hi, I have a white knight cl847, on the high heat setting the drum spins for a few seconds stops, then spins for about a minute in the other direction seems to be heating up then stops, the reset button does not need pressed. If I wait for a minute it comes back on when the start button is pressed. On the low setting the dryer seems to run ok but with no heat. I have replaced the brush at the top of the drum and the exhaust sensor. Do you think it’s the element? Any help would be great.