A software bug has hit tons of Nest smart thermostats, draining the batteries and knocked heating systems offline, just as a cold snap arrived in the UK.
Nest owners have reported waking up to frigid homes over the past few days.
The firm stated the issue stems from an update that was released last month – but has not yet been able to fix it.
Some of those affected took to Nest’s own forum and social media to vent their anger about the problem.
Why does it seem like my @nest is always offline?! #frustrating
— Melissa Reid (@MrsMelissaReid) January 7, 2016
@nest what's going on with the server? My gen2 thermostat has been offline and low battery since this morning.
— CTrinh (@CTrinhTweet) January 8, 2016
Google-owned Nest said that it was aware of the issue and that it had been fixed for “99.5%” of users.
It recommended that, for those still experiencing problems “performing a manual reset should help”. It also published a nine-step fix.
The £200 Nest thermostat has been designed to learn the right temperatures for a home at any given time, potentially saving money on heating bills. Nest also offers a smoke alarm and security camera to allow users to keep an eye on their home via a smartphone.
The firm was bought by Google for $3.2 bn (£2.2 bn) two years ago.
Analyst firm Gartner predicts that 6.4 billion connected things will be in use in 2016 but it warns that the costs of making sure such systems were secure would also rise.