Learn about using a Nest thermostat with a system that includes a hot water programmer

Depending on which Google Nest thermostat model you have, it either replaces your existing hot water programmer or integrates with a separate hot water programmer.

Select your Nest thermostat model below to learn about how it integrates with hot water control in your home. If you’re not sure which model you have, see our article about how to tell which Nest thermostat you have.

Nest Thermostat E 

  • The Nest Thermostat E is designed to work with combi boilers. If you have an Open Therm system it can control the hot water temperature.
  • If your domestic hot water system uses a separate hot water tank, the Nest Thermostat E can not control hot water. Instead, we recommend installing a 3rd gen Nest Learning Thermostat which can schedule when your system heats the water in the tank.
  • If you install a Nest Thermostat E on a system that has domestic hot water, you’ll need to keep your existing programmer. You’ll set the programmer heating schedule to always on while keeping your current domestic hot water schedule.

3rd gen Nest Learning Thermostat 

The 3rd gen Nest Thermostat can control your domestic hot water as well as your heating.

  • If your current thermostat controls both your heating and your hot water, you can simply have a 3rd gen Nest Learning Thermostat installed. There’s no need to install a separate hot water programmer.
  • If you currently have a thermostat and a separate hot water programmer, the 3rd gen Nest Learning Thermostat will replace both.

2nd gen Nest Learning Thermostat 

With a 2nd gen Nest Learning Thermostat, you keep the functionality of your current hot
water control. So if you already had a hot water programmer, that didn’t change when you
installed a 2nd gen Nest Learning Thermostat.

  • If you had a programmer that controlled both heat and hot water, your installer will have
    disabled the heating channel of the programmer when they installed your 2nd gen Nest
    Learning Thermostat. Your hot water continues to be controlled by your programmer.

  • If you replaced a thermostat that controlled both your hot water and heating, your
    installer will have replaced it with a 2nd gen Nest Learning Thermostat, which controls
    your heating. Your installer may have also installed a simple hot-water-only programmer
    (or your old programmer, if you had one) to control your hot water.

Note: In Ireland, it's common to have a single channel hot water programmer and switch heating on or off with a manual lever.

Was this helpful?
How can we improve it?