How to Wire a Thermostat to a Circulator

Turn off water circulation using the switch on the circulator controller. Allow the circulator system to drain. Turn off power to the electrical circuit on which you'll be working.

Install the thermostat directly on the system pipes, so that it is able to most accurately sense water temperature. The thermostat should come with clamps or clips that you can use to attach it.

Use wire strippers to remove the insulation from about an inch of the ends of the thermostat wiring, being sure not to cut the actual wiring. Connect the wiring from the thermostat to the wiring on the circulator controller. Connect like colors together, using wire nuts.

Fill the hot water tank with water. Turn on the circulator switch, allowing water to flow through the pipes. Allow water to run for a length of time, and monitor whether the thermostat and circulator are properly connected by determining whether the circulator shuts off and turns on according to thermostat readings.