Some Google Nest thermostats can control hot water in addition to heating your home. Depending on your thermostat model, it may work with a simple On/Off hot water tank, an OpenTherm hot water tank or an OpenTherm combi boiler.
Before you start
Make sure that your Nest thermostat works with your domestic hot water system. Refer to the table below.
How to tell which Nest thermostat you have
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Nest Thermostat E
|
3rd-gen Nest Learning Thermostat1
|
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Separate hot water tank with On/Off control
|
-
|
|
|
OpenTherm2 combi boiler (hot water temperature)
|
|
|
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Proprietary systems
|
-
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-
|
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Electric hot water tanks
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-
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-
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1 Only the models listed in the table above can control hot water. The 2nd-gen Nest Learning Thermostat doesn't control domestic hot water.
2 Check for the OpenTherm logo 
on your boiler, or contact your system’s manufacturer and ask about your model. To save more energy, learn more about how the Nest thermostat works with OpenTherm.
Separate hot water tanks (On/Off or OpenTherm)
If your system has a separate On/Off or OpenTherm hot water tank, and your Nest thermostat is compatible (check the table above), then your thermostat can control when your system heats the water in your tank.
Tip: If you have a combi boiler, these features aren't available because hot water is produced on demand.
Set up a hot water schedule
Automatically stop heating water when nobody's home
Get hot water on demand (Boost)
If you need hot water for longer or at a different time than what’s scheduled, you can use Boost to heat the water for a specified duration. After that, your hot water tank goes back to its regular schedule.
With the Nest app
- Open the Nest app
.
- Select Hot water
.
- Tap the large Boost button.
- Choose how long you want to boost hot water.
On your thermostat
- Press your thermostat's ring and select Hot water .
- To select how long you want to boost hot water, turn the ring, then press your thermostat ring to start.
Note: The menu should say 'Stop boost' if hot water is already being boosted.
Manually turn water heating on or off
Set hot temperature (OpenTherm only)
OpenTherm combi boilers
If you have a system that uses an OpenTherm combi boiler and your Nest thermostat is compatible (check the table above), then your thermostat may be able to control hot water temperature.
Tip: You don’t need to create a schedule or control when hot water turns on because combi boilers produce hot water on demand.
Set hot water temperature
In many cases, your Nest thermostat should be able to control water temperature with a combi boiler that’s OpenTherm compliant. So, you can turn up the water temperature in the winter for a warmer bath or shower, and turn it down in the summer to feel more comfortable in hot weather or to help save energy.
However, because OpenTherm standards can vary, your boiler might not be able to do this. If this is the case, you should be able to set the water temperature manually on your combi boiler.
To find instructions for setting hot water temperature, select your thermostat below.
Nest Thermostat E
Use your thermostat to set the hot water temperature.
- Press your thermostat's ring and select Settings
Equipment.
- Your current equipment and settings should appear. Select Continue.
- Select Hot water temp and then adjust the hot water temperature to your preference.
Tip: The minimum temperature setting for combi boilers with OpenTherm control (40ºC) (104ºF) is lower than hot water tanks (55ºC) (131ºF). Combi boilers do not store hot water in a tank and the risk of the formation of Legionella bacteria is very low.
Troubleshoot hot water control
If there aren’t any options
Check your thermostat model
Domestic hot water control is not available for the 2nd-gen Nest Learning Thermostat. In addition, not all Nest thermostats support all types of hot water systems. Check the table at the top of this article. If you’re not sure which thermostat you have, learn how to check which Nest thermostat you have.
Check the installation
If your thermostat is compatible with your hot water system but there are no hot water controls in the app or on the thermostat, you or your installer may have set up your thermostat to control heating only. If that’s the case, then hot water is controlled by your system programmer rather than your thermostat.
Contact a Pro installer
You can always contact a professional in your area to help you configure your thermostat to correctly control your domestic hot water.
If there are some options for hot water
Some of the options listed above don’t appear for certain types of hot water systems.
Simple hot water tank with On/Off controls
There's no option to control water temperature. That’s because this type of system doesn't support water temperature control through the Nest thermostat.
Combi boiler
Your combi boiler produces hot water on demand. So, there are no options to create a schedule, automatically switch temperature or boost your hot water.
.
Schedule 
.