Pick the gentler reset first. Most "my Nest is acting weird" problems are software hiccups that a restart resolves in 90 seconds. Factory reset is the nuclear option — it removes the thermostat from your Home app, wipes the schedule, learning data, and equipment configuration, and forces full setup again. Restart preserves everything. The flowchart is short: restart → if not fixed, restart from the menu → if still not fixed, factory reset and re-onboard.

Restart (soft reset) — Learning Thermostat (1st, 2nd, 3rd, 4th gen)

  1. Press the ring once to wake the display.
  2. Turn the ring to highlight Settings (gear icon) and press the ring to select.
  3. Scroll to Reset and press the ring.
  4. Select Restart and confirm.
  5. The thermostat reboots in about 30 seconds. All settings are preserved.

If the menu is unresponsive, do a manual restart: pull the thermostat head straight off its base (it pops off), wait 10 seconds, push it firmly back on until it clicks. The thermostat boots fresh with all settings intact.

Restart — Nest Thermostat E

  1. Press the ring to wake the display.
  2. Turn the ring to Settings and press to select.
  3. Choose Reset, then Restart, then confirm.

For a hardware restart on Thermostat E: press the display in toward the wall for about 10 seconds until the screen goes black, then release. Press and release the ring once to power back on.

Restart — Nest Thermostat (2020 model, the budget one)

  1. On the side, press and hold the button for about 10 seconds until the screen turns off.
  2. Release the button. The display will power back on automatically.

Before any factory reset — save your setup

  • Photograph the wiring. Pull the thermostat off the base and take a clear photo of the connector block with the wire colors visible.
  • Write down the equipment settings: go to Settings → Equipment and note system type (heat pump, conventional, etc.) and accessory wiring.
  • Note any custom schedules, eco temperatures, and safety temperatures.
  • Confirm WiFi password is available — factory-reset Nests need full re-onboarding through the Google Home or Nest app.

Factory reset — Learning Thermostat

  1. From the home screen, press the ring to open the menu.
  2. Turn to Settings → Reset → All Settings.
  3. Confirm. The reset takes a few minutes.
  4. The thermostat shows the welcome screen. From there, follow the on-screen prompts and re-add it through the Google Home app (current) or Nest app (legacy).

Factory reset — Nest Thermostat E and 2020 Nest Thermostat

Both models reset through the same menu path: Settings → Reset → All Settings → confirm. Older Thermostat E units may show the option as Factory Reset rather than All Settings.

When to factory reset vs leave it alone

  • Restart is enough: WiFi drops, frozen screen, missed schedule changes, won't respond to ring, software-update hiccup.
  • Factory reset is the right move: selling the home, moving the device to a new property, transferring ownership to another Google account, persistent issues that survive multiple restarts, locked PIN you no longer have.
  • Don't factory reset for: a single WiFi blip, a one-time temperature swing, or a missed wake/sleep transition. Try the gentler fix first.

After a factory reset

  • Re-add the thermostat in the Google Home app (newer Nests now require Google accounts and the Home app).
  • Re-enter the equipment configuration from the wiring photo and the settings notes you saved.
  • Re-confirm the schedule, eco temperatures, and any home/away routines.
  • Rejoin household members to the home so everyone has app control.
  • The Learning algorithm starts over — expect a week or two before it re-learns your patterns.

Good maintenance rhythm

  • Monthly: check the battery icon (Learning and E models have an internal battery topped up by HVAC wiring).
  • Quarterly: confirm the schedule still matches your routine; adjust seasonally.
  • Twice a year: pull the thermostat off the base and wipe the connector pins with a dry cloth.
  • Yearly: review the equipment settings after any HVAC service or new accessory.
  • Ongoing: restart before factory reset; factory reset only when the situation truly warrants it.
Add reminders to the HomeSaver mobile app to always stay ahead of your home maintenance.

Sources