Hey! We’ll break the Nest firmware update loop and get your device back online. Quick questions so we pick the right fix (Nest devices behave differently during updates):
• Which device is looping: Nest Thermostat, Nest Camera/Doorbell, Nest Hub, Nest Audio, or Nest WiFi?
• What do you see exactly: “Updating…”, “Downloading update”, “Update taking longer than expected”, a percentage that resets, or a reboot loop?
• Is it already added in the Google Home app (or older Nest app) or stuck during setup?
• Wi-Fi details: are you on mesh Wi-Fi, a combined SSID, or a dedicated 2.4 GHz network? Any recent router changes, new password, or firmware update?
Tell me those 4 things and we’ll do the fastest “no data loss” steps first (power + Wi-Fi + app), then only factory reset if we have to.

Got it — the Nest thermostat stuck updating scenario is common when something interrupts the download/verify step. The main causes are:
• Unstable Wi-Fi (weak signal, mesh roaming, band steering, captive portal, or packet loss) so the update restarts.
• DNS or firewall filtering blocking update endpoints (some “ad-block” DNS profiles can accidentally break updates).
• Power instability (low battery / no C-wire issues can cause reboots mid-update).
• A “hung” update process where the device needs a forced restart to finish cleanly.

We’ll do this fast in a safe order:
1) Confirm power + battery isn’t the trigger.
2) Stabilize Wi-Fi (especially 2.4 GHz / mesh settings).
3) Restart the thermostat to “unstick” the update.
4) If it still loops, do an app-side cleanup (remove/re-add) or a factory reset as a last resort.

Perfect — we’ll prioritize “keep settings” steps first.
Step 1 — Check power (this prevents update reboots)
1) On the thermostat, go to Settings → Technical Info (or Battery/Power info, depending on model).
2) If you see low battery warnings or the device feels “sluggish,” that can cause a Nest update restart loop.
3) If your model can be charged via USB (some displays can), a short charge can stabilize it during the update. If it’s hardwired, we just confirm it’s not power-cycling because of wiring.

Step 2 — Check Wi-Fi signal where the thermostat sits
• Mesh networks can roam devices between nodes; during firmware updates this can break the download/verify process.
• If possible, place a mesh point closer or temporarily move the thermostat (or node) to get a stronger signal during update.
• If your mesh supports it, try temporarily turning off “smart steering” / “band steering” or creating a dedicated 2.4 GHz SSID for smart devices.

Once we stabilize those two, the restart step usually completes the update within minutes.

Great — that message usually means the device can’t consistently reach the update servers.
Step 3 — Put Nest on the most stable network (fastest fix)
1) Create 2.4 GHz SSID (example: Home_IoT_2G) with WPA2-PSK (AES) if possible (avoid WPA3-only while troubleshooting).
2) Move the mesh point closer OR temporarily use the main router (less roaming) for the update window.
3) Reconnect the thermostat to that stable SSID (Settings → Network).

Step 4 — Restart the thermostat to break the firmware update loop
• If it’s been stuck more than ~15 minutes: do a restart from Settings (or hold the device control to force a reboot, model-dependent).
• After reboot, leave it alone for 10–15 minutes. Avoid opening/closing settings repeatedly (some models restart the update check).

Step 5 — Router-side quick wins (if it loops again)
• Reboot router/mesh (power off ~60 seconds → on).
• Disable “AP isolation / client isolation” on the IoT SSID if enabled.
• If you use custom DNS/ad-block DNS, temporarily switch to default ISP DNS or a standard public DNS just to test update completion.
This combination fixes most “Nest stuck updating software” loops without factory reset.

Yes — sometimes the device is fine, but the update state in the app becomes “sticky,” especially if you migrated devices between Nest app and Google Home or changed Wi-Fi mid-update.
Step 6 — App-side refresh (safe, doesn’t wipe the thermostat)
1) Force-close the Google Home app and reopen it.
2) Make sure the phone is on the same network as the thermostat (Home_IoT_2G is fine).
3) In Google Home: open the thermostat device → Settings → check Wi-Fi/network status and confirm it’s actually connected where you expect.
4) If the Home app is clearly wrong (shows offline while thermostat is working), sign out/in of the app once (rare, but helps).

Step 7 — For cameras stuck “downloading updates”
Nest cameras/doorbells are even more sensitive to Wi-Fi drops during firmware updates. The fastest fix is a clean power cycle + stable 2.4 GHz signal, then wait. If it’s still stuck, we do a factory reset and re-add in Google Home (last resort).

If your thermostat still reboots every time it verifies the update, DNS filtering is a big suspect. Any Pi-hole / “family safe DNS” / router security filters enabled?

That’s a strong clue. Network-level ad blocking can block update checks or certificate validation, which creates a repeating firmware update failed loop.
Step 8 — Quick DNS test (fast, reversible)
1) Temporarily switch router DNS to default/automatic (or a standard public DNS) for 15–30 minutes.
2) Keep the thermostat on 2.4 GHz with strong signal and try the restart one more time.
3) Let it complete without interruptions. If it finishes, you can turn your DNS profile back on and then whitelist/update-allowlist if your DNS tool supports it.

Step 9 — If it still loops: factory reset (last resort)
A factory reset is the “clean slate” fix when the update state is corrupted. It can remove some local settings depending on model, but it’s often the fastest way to stop a Nest stuck updating issue that keeps restarting. After reset, re-add it in the Google Home app on the stable 2.4 GHz SSID and let it update immediately (don’t change networks mid-setup).

If you tell me your exact thermostat model (Learning Thermostat gen / Nest Thermostat 2020, etc.), I’ll point you to the correct reset path so you don’t wipe more than necessary.

Nice — that confirms it was network filtering + stability during the update.
How to prevent a Nest update loop (thermostat, camera, hub)
• Keep a dedicated 2.4 GHz IoT SSID and avoid changing SSID/password often. Updates hate mid-stream network changes.
• On mesh systems, keep the device near a stable node during updates (avoid roaming). If your mesh has “device priority” or “stick to node,” use it.
• If you run Pi-hole / ad-block DNS / security DNS: create an allowlist for Google/Nest update traffic (or temporarily disable filtering during updates).
• Avoid WPA3-only on IoT. If you use WPA3 on your main network, consider WPA2 for the IoT SSID for compatibility while troubleshooting.
• After a router firmware update, re-check settings like client isolation, DNS, and IPv6 (some routers flip defaults).
These steps massively reduce “update taking longer than expected” and random Nest reboot loops.

Same core idea (stable power + stable network), but here’s the fastest device-specific path:
Nest Cam / Nest Doorbell stuck downloading updates
1) Power-cycle (unplug/turn off breaker if wired) → wait 30–60 seconds → power back on.
2) Ensure strong Wi-Fi signal (prefer 2.4 GHz, avoid roaming/extenders during update).
3) If it’s still stuck for a long time, factory reset and re-add in Google Home on the stable SSID (last resort).

Nest Hub / Nest Audio “update taking longer than expected”
1) Unplug device for ~1 minute → plug back in.
2) Reboot router/mesh for ~1 minute.
3) If it keeps looping, factory reset and set up on 2.4 GHz if available.

If you ever see a repeating 0%→99%→restart style loop, it’s almost always signal/packet-loss or blocked update traffic, not “a broken screen.”

Summary: To stop a Nest firmware update loop, stabilize power, put the device on a strong 2.4 GHz Wi-Fi connection (avoid mesh roaming during the update), reboot router/device, and temporarily disable DNS/security filters that can block updates. If it still won’t finish, a factory reset + clean setup in the Google Home app is the last-resort recovery. Want me to tailor it to your exact Nest model and router? Open the chat and we’ll fix it step by step.