Why doesn the temperature on the thermometer correspond to the temperature of the heater surface?
The dial thermometer on the heater indicates internal temperature. Some heat is lost on the transfer of heat to the outside of the heater adapters. Strong wind currents can also drop the surface temperature below the desired setting. Keep the heater in the insulated heater stand, when not being used to heat pipe ends. Loose heater plates or foreign material between the heater and the heater plates will also cause a drop in the surface temperature and the internal reading of the heater plate.
