how does Nest switch on/off my hot water?

dubb

Hi,

Nest is decribed as a low current switch. 
How does it switch on/off my immersion - 13A / 3 kW?

Thanks

Electric Ireland: David

Hi dubb,

Thanks for getting in touch.

Do you have an electric immersion? The 3rd Generation Nest can control hot water provided the water boiler is connected to your heating system. As electric immersions aren't generally connected to a heating system, the standard installation of the Nest wouldn't control an electric immersion.

For more information, see the following link on the Nest website:

What kind of hot water tanks can be controlled by the 3rd-generation Nest Learning Thermostat?

Please let us know if you have any other questions.

Thanks,
David

dubb

Aren't most immersion heaters electric?

Your answer is as I expected, but I think there's misinformation out there from nest (probably because they consider US households more than Irish homes), and perhaps even from EI. Consider the text below from your link. Most hot water tanks do NOT use a 3A switch.

---

Because the 3rd-generation Nest Thermostat can control domestic hot water, it can replace your hot water programmer. The 3rd-generation Nest Thermostat works with most domestic hot water tanks connected to a heating system

Most older hot water tanks use a simple On/Off control over 240 V and 3 A current max. The Nest Thermostat can control these hot water tanks, and you ll be able to set a hot water schedule

EI: Aoife

Hi again dubb,

Thank you for getting back to us.

A member of our Home Services department would like to give you a call.

Can you please send us a private message with your full name, your contact phone number and the best time to give you call?

If you have any other questions, please do not hesitate to ask.

Thanks,
Aoife