Temro's of Canada makes an energy saver cord that goes around the Inlet interior heater hose. This unit sense the temperature of the hose and will turn the block heater on until the hose temperature reaches 40 degrees F. The unit can handle up to 1500 watts. Part number 3600013 phone 204-667-2260 I purchased mine at the local NAPA store in Fairbanks AK I think the price was around $30. two years ago.