Modine 75K nat gas heater won't cut on. Pilot is lit, and it has power going to it. There is no thermostat for this unit. I cant find a reset button.

How do you control on and off heat? is there a thermocouple?

The only one I see is the one that senses the flame. This is a heater in our basement at work. Last winter we would just turn the breaker off and on when the room got to a comfortable level. This winter the unit would not turn on at all. Is there a reset button on these? The unit does not try start or do anything when you apply power. Any suggestions would be appreciated.

That's a HUGE heater for just a basement.