Abstract: The present invention relates to a system for heating the well head assembly of a conventional oil well pumper. The system functions by routing a portion of the engine coolant from the pumper engine to a heat tracing loop. This loop enables a portion of the coolant to heat a well head assembly. Such heating reduces well head freeze ups and consequent well shut downs. The present invention also employs a temperature regulator which functions in optimizing the amount of engine coolant routed into the heat tracing loop. An amount of vaporizable fluid is in thermal contact with the heat tracing loop. Increased tempertures within the loop serve to vaporize the fluid. This vaporized fluid is then employed within an expansible bellows. Expansion of the bellows serves to open a poppet valve and decrease the amount of coolant routed through the loop.

Abstract: A indicating power cord system including a housing and an elongated extension cord having a first end connected to the housing and a second end having a plug coupled thereto for being releasably inserted in a standard electrical receptacle to receive power therefrom. Next provided is an electrical outlet positioned on the housing for being electrically connected to a block heater of a vehicle. The electrical outlet is electrically connected to the extension cord with a relay contact and associated relay coil connected therebetween. The relay contact has a closed unbiased orientation upon the lack of receipt of current by the relay coil and an open biased orientation upon the receipt of current by the relay coil. Also included is a thermistor positioned on the heater block of the vehicle. The thermistor can be connected to the relay coil for providing current thereto upon the engine block reaching a predetermined temperature.