The 3rd control knob, the one that's all the way to the right of the heater control felt like it was stuck. I tried to change the selection and had to force it a little and that's when it broke off. I went looking for a replacement on Ebay and found that this seems to be a common problem. There were several auctions for the knob and they were all expensive, in the $20 and up range. A quick look at completed auctions shows that there is no shortage of buyers, hence the inflated prices. BE ADVISED....there are 3 different types of control knobs. They all look the same from the front but the backs are different. If you get a replacement from Ebay or somewhere else, make sure that the back of the knob looks like the one you need or else it won't work for you.