The Nest Protect is a connected home smoke and carbon monoxide detector. Much like Nest’s smart thermostat, the company has taken what is generally an unremarkable, mundane household object and re-engineered it so it now not only looks good, but has several smart features built in.

The annoying chirps in the night for a low battery are a thing of the past with the Nest Protect but there is a lot more to it than just that. If your home was built pre 2006, the chances are that the smoke detectors in your home are now due to be replaced. It’s something most people don’t know or even think about but the detectors do expire over time. I don’t know about you but until recently I have never checked the efficacy of the smoke detectors in my home. It was only when you burned toast that they might go off and even then you probably hoped they didn’t but what happens if you don’t burn toast for ten years?

The last time I heard someone from Nest speaking at a conference they came out with a stat that really resonated with me: 85% of house fire deaths in America in the previous year occurred in a house that had smoke detectors that were not working properly. The take home message here is no matter what detectors are in your home, check their age and check that they actually detect smoke!



The Nest thermostat is made with stainless steel and glass. Nest wanted it to stand out in a room and become a focal point. The Nest Protect takes a less glamorous path and uses white plastic as its construction material. No doubt this was partly to keep costs down and partly due to fact it will most likely live on a white ceiling when installed.

That’s not to say it feels cheap or resembles the old smoke detectors it replaces. Far from it. When you take the Nest Protect out of its box, it feels just as premium as Nest’s other products.

The square design is in contrast to the usual round shape of most detectors. The sides are 135mm and it’s 38.5mm thick. The front face has a series of holes in a spiral pattern surrounding the Nest logo in the middle. That centred logo also has a light ring surrounding it which changes colour depending on the current conditions. Screen Shot 2016-04-12 at 12.43.52 a.m.

It’s easy to understand and the addition of features like the Pathlight, which lights up your way when you walk near the detector at night time, is a nice touch.

Overall the general design is the polar opposite to that of the traditional cheap plastic smoke or CO detectors that we are used to seeing in homes.

So we have established it looks good and is designed well but more importantly, how well does it work? Read on….

Fitting & Setup

The Nest Protect comes in two versions. The only difference is one is suitable for mains wired installations and the other works off of a battery only. It is regulation in Ireland now that new homes are fitted with wired alarms. They still have a battery installed but this is just for back up for when the power goes down.

The unit we tested was a wired model but as I mentioned, both are functionally the same so the review is applicable for both models. I need to point out here though, if you are planning on installing one of these units and your home has wired detectors, it must be fitted by someone who is electrically trained. This is a really important piece of technology for keeping your family safe. With most items like this I would say whether it is within the capability of someone who is good at DIY but for something like this, take no chances.

If you are fitting the battery model yourself, there is a mounting plate which you need to attach to the wall or ceiling with two screws and the Nest Protect then attaches to that. It’s all simple enough.

The setup is completed via the Nest app on your smartphone and you need to complete this before you mount the unit.

Nest don’t publish exact figures for how long the batteries will last in the unit, only that it is expected to be multi-year. Obviously it will depend on how often it is called into action and let’s hope that’s kept to a minimum!


After setting the Nest Protect up with the app there’s thankfully not too many reasons you should need to revisit it unless something is wrong.

If there is smoke or CO detected the app will notify you straight away. The app also lets you know when the detector is carrying out self checks where a sound will be emitted so people don’t think it’s a real alarm. You can check the history of the daily self checks that the detector performs and if anything else out of the ordinary happens such as a power cut (wired model) the app will list it within.

If there is only a small amount of smoke, such as your toast burning, the app will give you a heads up rather than an all out emergency sounding of the alarm. This is a great feature and saves you from having to get the tea-towel out to wave frantically underneath the detector to silence the alarm!

Smart functions & Home Automation

There are several areas here where the Nest Protect improves the user experience and usability of the detector over the “dumb” models it replaces.

When you set up the device, you name the location where it is. So if you have one placed in your kitchen and it picks up some smoke from the burning toast, the app will give you a heads up and tell you which detector and where in your home it has picked it up. The idea here of course is that you will have multiple Nest Protects around your home and therefore you’ll be able to locate exactly where the problem is in a far quicker manner.

The unit performs a daily self test and a weekly test to check all the components are working. On the weekly test it sounds the alarm to check it is still working. You can also manually test your devices from the app. Every night when the lights are turned out in the area the device is located, the ring light glows green to tell you that the batteries are good enough to at least last through the night thus bringing an end to the low battery warning chirp in the middle of the night! If the batteries are running low the app will tell you well in advance of it becoming a problem at 3am in the morning.

If there is an issue, the app can inform more than one person in your home too as long as they have the Nest app installed on their smartphone (think elderly relative/ heavy sleeper/ hard of hearing etc.)

You can also interact with other smart devices in your home if there is an emergency. Nest obviously hope you will be adding a Nest Protect to a home that already has a Nest thermostat installed and as such there are additional benefits if you are. If there is a CO or Smoke alarm activated the heating will be shut off to insure the problem isn’t added to.

You can also reach further using a service such as IFTTT. Using this service you can set an alarm on the Nest Protect to turn on your smart bulbs in your home to light up your path out of the house for example.


There’s no doubt that the Nest Protect is a great product. It drags smoke detectors into the 21st century and removes many of the annoyances associated with the previous models.

The big elephant in the room here though is price. At €109 they are going to be a hard sell for many, especially if you want to have multiple detectors across your home.

If you can get over the price and you are integrating these into a current smart home setup then the Nest Protect is easy to recommend.

Nest Protect Review
4.1Overall Score
Ease of use

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