Heat regulator
I believe the answer is:
thermostat
(Other definitions for thermostat that I've seen before include "Temperature controller" , "Temperature regulator" , "Heating device" , "Form of control" .)
I believe the answer is:
thermostat
(Other definitions for thermostat that I've seen before include "Temperature controller" , "Temperature regulator" , "Heating device" , "Form of control" .)