2006 holliday rambler admiral

"Bloyce"......It's a small disc within a few inches (less than 6") of the heater. Just some info if you're new to a Monaco bay heater. You should have a switch inside the coach with an adjacent indicator light. When you turn the switch "ON", the light DOES NOT light up. Turning the switch on, only activates the unit. When the temperature drops to a certain level in the bay, somewhere around 28 degrees, the indicator light, inside the coach, will come on, showing that the heater is on. As soon as the temperature is reached, somewhere around 35, the light goes off. I use to know the temp numbers, but it's been a long time.

You can test the system by turning on the switch and placing an ice cube against the sensor for a while.