I had a T622CW with no heat. I traced it to one of the thermal cut out switches (thermostats). I put a multimeter across it and found it to be open circuit. I have by-passed it and it works. I will leave it like that 'till I find a replacement. I also checked the elements by putting a multimeter across them and looked for resistance. I did not check the rest of the circuit but I presume the only other component would be timer switch.
Norrie Dorans, January 2005