How to Wire a Thermostat to a Circulator

Connecting your hot water circulator to a thermostat allows you to heat your home efficiently.

A circulator is the set of pipes responsible for distributing hot water throughout your home, and a thermostat regulates the temperature of the hot water and turns the water pump on and off to keep water flowing through the pipes at a constant rate and temperature. Wiring a thermostat to a circulator is not a complicated process, although it requires some concentration and materials that you can find at the hardware store.

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.

Things You Will Need

  • Electrical wiring
  • Wire nuts
  • Wire stripper
  • Thermostat


  • The type of circulator tubing you are using is extremely relevant to the efficiency of the thermostat. PVC tubing, for instance, less readily conducts heat, so a thermostat attached to PVC may not be able to sense water temperature accurately and work efficiently. On the other hand, copper or steel tubing will work more efficiently and each kind of tubing has specific types of thermostats with which it will work particularly well.


  • Improperly wired electrical circuits can cause electrical shock and even death. Consult with an experienced electrician before attempting this project.

About the Author

Tricia Lobo has been writing since 2006. Her biomedical engineering research, "Biocompatible and pH sensitive PLGA encapsulated MnO nanocrystals for molecular and cellular MRI," was accepted in 2010 for publication in the journal "Nanoletters." Lobo earned her Bachelor of Science in biomedical engineering, with distinction, from Yale in 2010.