Google Nest Thermostat never turns off

[Shia]

Hi all,

I purchased a Google nest thermostat and connected it to our new tankless water heater. As soon as I mount it on the wall, the heat turns on-regardless if the thermostat is set to a low temp. Or completely off.

There is no schedules or hold set.

I had a technician inspecting the wires and installation and even had Google sending me a replacement unit but it has the same issue. 

There are no error codes.

I purchased a cheap honeywell unit just to see if I'm getting the same issue but it works perfectly. 

Wiring is C W R

Thanks

[ByronP]

Hi Shia,

Thank you for posting. I'm sorry that your Nest thermostat never turns on with your new heater.

Before we continue, we need to ask a few questions to verify the main issue that caused the thermostat to turn off.

1. What type of Nest thermostat do you have?
2. Do you have a Heat Link?
3. What type of heater have you installed before?

Please keep me posted.

Regards,

Byron

[Shia]

Hi,

thermostat never turns OFF our nation tankless water heater. Seems like it's sending power to the W wire all the time, even if it's set to off. Water heater only turns off when I unmount the thermostat 

[ByronP]

Hi Shia,

Thank you for posting the details.

For this concern, please fill out this form. Our specialist team will reach out to you soon for further assistance with this issue.

Let me know once you're done.

Regards,

Byron

[Shia]

Please provide form

[ByronP]

Hi Shia,

Thank you for posting. I'm sorry, my bad. Here is the link to fill out the form.

Let me know once you're done.

Regards,

Byron

[Shia]

Hi Byron,

Form has been filled out

Thanks!

[ByronP]

Hi Shia,

Thank you for posting. I got your form, and our specialist team will reach out to you soon for further assistance on your issue.

Regards,

Byron