[HayZee518]

A question for you. where is your temperature detector mounted? at the rear and slightly above the back cabinet? remote of the whole heater? on a wall above the heater? the temperature thermister is very sensitive to temperature changes. it is responsible for the general room temperature. if it is mounted so it contacts a wall's surface, it will keep calling for heat unless it's tip temperature reaches the set point of the computer. the senser should be mounted so there is free air all around it. my brand new 2400 operates 24/7 rarely does it reach the set point. the room temperature over shoots the set point by two or four degrees before it goes into a shut down. as far as running on low for an extended time yes it is normal. its sort of like throttling down as the set point is reached.