Abstract: An energy control and transmission system which monitors temperature in piping systems, electronic systems and the like. Energy in the form of a heated or chilled fluid is delivered to the devices and/or regions of interest to maintain temperature conditions thereat within a safe range of values. Electrical energy employed in the system is confined to the location from which the fluid is pumped, eliminating the presence of electricity in hazardous or dangerous areas. Non-electrical temperature indicators are utilized to permit branching flow of the temperature controlling fluid from a closed loop responsive to detection of a temperature condition outside of the desired range of values. The opening of such a branching path triggers operation of a pressure sensitive switch which activates a pump for delivery of the temperature controlling fluid.