Talkin Tech: Using the Nest Thermostat on Shabbos

By: Rabbi Mordechai Lebhar

לא תבערו
אש בכל מושבותיכם

The Nest is an energy efficient thermostat that senses when people
are in the house through cameras and the occupant’s smartphone and then
‘learns’ the occupant’s behavior, too.

If the heating or air conditioning is off, and one passes the Nest,
it automatically turns on. Obviously, this function must be disabled before
Shabbos.

What about the other ‘smart’ functions where the Nest is constantly ‘learning’ your habits and patterns to determine when you generally sleep or go away? Based on that, it automatically activates utilities in the home.

The potential issurim:

  1. Activating the air conditioning is probably medrabanan; the heater is more likely a de’oraysa.
  2. While it is ‘learning’, the memory is being recorded on the magnetic card. This could be tikun mono/make bepatish or molid.

The potential hetterim:

  1. There are multiple algorithms for the Nest to decide how – or if – to modify and change the temperature. This means it is a safek psik reisha.
    1. Usually safek psik reisha is subject to the machlokes between the Taz and Rav Akiva Eiger, and Poskim are generally lenient on issurei derbanan; however, here, the resident is interested in the Nest learning his behaviors; therefore, we say he is nicha lay, which would necessitate being more stringent.
    1. There is a potential solution, whereby, in addition to removing the auto turn on function when one passes by, the occupant sets an override schedule [and intentionally leaves his phone at home]. This way, he is demonstrating that he does not want the Nest to learn his true habits on this day, thereby resulting in a safek psik reisha where it is lo nicha lay.