I have a Camray 5 around 14 years old which switches off after the initial 15 min burn. The wall thermostat has not clicked off. If I then either turn off the power or click off the wall thermostat and then back on again it comes back to life. It then does the normal procedure, burn for a few minuits then off for a few minutes then back on until the wall thermostat clicks out. This is a intermittent problem somtimes it works ok.