O-rings for heated machines?

I was using my heated machine and surface cleaner the other day and went through TONS of o-rings. Went to my local harbor freight and even picked up a viton o-ring kit and still blew out tons of them. Can anybody point me in the right direction on which ones i should be buying?

Envirospec has special high temp Orings. You might be having a problem with maintaining a constant temperature. Is your water turning to vapor steam at times?

only after hitting the cold ground! lol