Dimming Thermostat - general questions

[Normnet]

I did a similar project; A PID algorithm temperature controlled laminator.
It used HPWM to operate a zero crossing solid state relay.
The PIC HPWM at lower settings operates the SSR more off than on and visa versa at higher settings.
Darrel's low frequency PWM would be good however mine worked with regular HPWM.
I included the light in the rocker power switch with the heater to give a visual indication of the on/off pulsing of the SSR.

Norm