In the last few months, we've seen an increase of reports regarding a "w5 error" for Nest thermostats, causing them to be unable to connect to Wi-Fi. Some device owners have accused an update of being the cause of their woes, but whatever might be triggering the problem, Google tells us its a known issue affecting a very small number of users, and the company is issuing replacement devices if and when other troubleshooting methods fail.

Reports for w5-related issues stretch back to the end of last year on Google's Nest product forums, but the frequency of reports seems to be picking up in the last three months or so, and one seemingly primary thread on the subject has over 200 replies at the time of writing. Those with the problem are unable to connect their Nest thermostats to Wi-Fi or, consequently, remotely control them. When examined, the thermostats themselves show a w5 error in settings, which can apparently appear in a handful of different ways:

Two different w5 connection error screens you might see. Images via "" on the Google Help Forums.

While general Wi-Fi woes are almost unavoidable sometimes — especially with smart home hardware — this upswing in w5 error reports has a twist: Most of the folks responsible for this recent increase in reports are reportedly unable to resolve their issues with the traditional troubleshooting methods.

Some of those that are running into problems claim the issue first happened immediately following an update to their Nest thermostats, though the details (and level of detail) included with customer reports vary. Some speculate that their "Wi-Fi chip" was somehow "fried."

Whatever the precise cause of the problem may be, we reached out to Google for more information about it, and a Google spokesperson informed us that it is an issue the company is aware of. In the event troubleshooting fails, the company is issuing replacements — though, based on reports, you might have to jump through a few hoops with customer support to get them.

"A very small number of Nest thermostat users are experiencing a known issue with the Wi-Fi chip that causes remote connectivity issues. This does not affect the thermostat’s ability to control the customer’s heating and cooling system in the home, but does impact the user’s ability to manage the thermostat remotely. If a user sees this error and it can’t be resolved through troubleshooting, they are prompted to contact customer support for assistance and will be issued a replacement device." - Google spokesperson

If you're among those that are suffering from a w5 error on your Nest thermostat and the troubleshooting steps here fail, try to reach out to Google's customer support for a replacement.

Source: Google Help Forums: (1), (2), (3), (4), (5), (6), (7), (8), (9), (10), (11), (12), (13)...

Header image via Fermion on the Google Help Forums.