5 Best Mains Powered Smoke Alarms

The quick answer is that the Aico Ei141RC is the best one, in our opinion.

We have installed 12 15 sets of mains powered smoke alarms in the last 12 months, so we feel that we have the authority on telling you what works and what doesn’t!

Before we give our 5 best hard wired smoke alarm systems, we’re going to reveal an overall winner, a runner up and one that you should probably avoid! Check out the table below.


Aico Ei141RC mains
Aico Ei141RC
  • Easy to install
  • 9V battery backup
  • Very popular


kidde interlinked
Kidde Firex KF20
  • Battery back up
  • Low cost alternative
  • Easy on the eye


cheap interlinked alarms
  • Poor instructions
  • Not great reviews
  • Hard to install

Our preferred mains smoke alarm is the Aico Ei141RC, due to the fact that is well priced, is easy to set up and install and has a 9V battery back up in case of the mains power going down.

If you’ve got more time to read, then we’re happy to tell you that we’re going to now reveal 5 of the best interlinked smoke alarms. We base our rankings on:

Naturally, all the systems we have installed has been professionally done by a suitably qualified electrician that is NICEIC qualified. If you’re needing something similar installing into your property, make sure the tradesperson you use is registered with NICEIC, Elecsa, Napit or another recognised body. You can read more about competent persons here.
Top 5 Smoke Alarms - Ranked!

Now that you have our preferred option, what about the rest? Sometimes referred to as an interlinked smoke alarm system by those in the trade, we now give our opinion on the 5 best mains powered units available on the open market.

Please note, we also discuss portable smoke alarms and smoke alarms for deaf people on other pages.

Aico Ei141RC Mains Ionisation Smoke Alarm

Our Rating:
Aico Ei141RC hardwired
Amazon’s Choice for “Mains Smoke Alarm”
  • Manufacturer: Aico
  • Weight: 349g
  • Size: 18 x 15.4 x 6 cm
  • Cost: £
  • Quality: Excellent
  • Installation: Easy

This one is our favourite. Easy to find, easy to install and very well priced. You can connect up to 20 of these smoke alarms, meaning they’re really good for very large properties. This can be done easily by hard wiring all the detectors or by using the wireless capability.

It comes with a 9V battery back up in case the mains power goes down.

We also made a mistake (or our electrician did) by putting an AICO heat detector in the bedroom instead of a smoke detector. Fortunately, you can keep use of the base and just change the head, so it was a five minute fix.

(Tip:  Read our guide on maintenance to combat potential fires.)



Kidde Firex KF20 Interlinked Smoke Alarm

kidde interlinked
Our Rating:
  • Manufacturer: Kidde
  • Weight: 340g
  • Size: 8.3 x 7.4 x 2.9 inches
  • Cost: £
  • Quality: Very Good
  • Installation: Easy 

Installation with this Kidde Firex detector is very easy. As long as you position the baseplate mounting appropriately, it goes straight on.

In fact, if you have an older baseplate from Kidde, the baseplate screw positions are still the same, so you can do a like for like.

Simply attach it on and then it locks in to place with a quick twist.

It comes with the 9V replacement battery and the device won’t allow you to mount it unless you put the battery in. Very smart.



Nest Protect 2nd Generation Smoke (Wired)

Our Rating:
nest wired smoke alarm
  • Manufacturer: Nest
  • Weight: 460g
  • Size: 5.3 x 1.5 x 5.3 inches
  • Cost:££££
  • Quality: Excellent
  • Installation: Difficult

We’ve talked about this one in our guide to the best carbon monoxide detectors and it deserves a place here too.

Yes, it is expensive and it can be costly once you start connecting several units, but it is the most advanced smart device for home safety.

A major plus point if you’re looking to upgrade is that the wired Nest system can be wired into the previous electrical wired system. The only difference is that the thermostat will need an additional wire installed.

All you need is the 120V hot (black) and neutral (white) wires in the electrical box connecting to the plug-in pigtail on the Nest.



First Alert SCO5 Smoke Alarm

Our Rating:
first alert sc05
  • Manufacturer: First Alert
  • Weight: 295g
  • Size: 8 x 7 x 2.5 inches
  • Cost: ££
  • Quality: Very good
  • Installation: Easy

This is a combined smoke and CO alarm which also includes a battery back up.

We used this model when we first started refurbishing houses. However, we were asked to supply the CO alarm separately, hence why we started using AICO ones instead.

It’s a really good one for homes and larger HMOs as you can hook up 18 compatible devices.

In addition to electrochemical sensors, the device can pick up on smouldering fires though its photoelectric sensor.

As a bonus, it comes with an ‘end-of-life’ battery signal meaning you can replace the entire unit with a brand new one.



FireAngel WST-630Q Radio Interlinked

Our Rating:
radio interlinked smokes
  • Manufacturer: FireAngel
  • Weight: 1213g
  • Size: 13.2 x 13.2 x 4 cm
  • Cost: ££
  • Quality: Very Good
  • Installation: Easy 

Very much like the ones above, these are easy to install.

The difference is that they are radio interlinked i.e. no need to be lifting up floorboards, connecting cables and so on.

Be careful that you don’t buy an older model. These tend to be the ones that people have been complaining about which gives off a false alarm.

The current model replaced the older model of the same smoke detectors.

You simply unscrew the old base plate, and install the new ones. After that, just connect them up wirelessly.

Check with your local fire risk assessor if they will accept radio interlinked alarms as not all local government housing departments do.



Hardwired Smoke Detectors - Where to Place Them

As mentioned at the beginning of this page, we’ve done about 12 Houses in Multiple Occupancy (HMO) this past year.

One of the main legal requirements when doing something like this is to install an interlinked smoke alarm system.

We always put smoke detectors in living rooms and bedrooms. Very rarely do we put a heat and smoke detector into a bedroom as we normally don’t offer cooking facilities in the bedroom i.e. we run our HMOs on a shared amenities basis.

This means that it is almost always in the kitchen that we have a heat detector instead of a smoke detector.

smoke detector placement

Naturally, as the wording suggests, these two types of detectors are interlinked, so if a fire starts in one room and sets of a detector, then the ones in every single other room will start beeping as well.

heat detector in the kitchen

What’s important is to locate a suitably qualified electrician that can offer this service for you.

We’ve been paying between £1100 and £1800 including labour and materials for a full system installation. The larger the property, the more detectors are needed.

As per our suggestion at the very top, we bought some AICO Ei141RC ionisation smoke alarm from Screwfix.

Remember though, once you’ve bought some of these, it’s not the end of it. It’s important that know how to maintain smoke alarms, wired or otherwise.


Radio vs Wired

Which one is better and more acceptable to local authorities? Let’s compare the two.

In some cases, local councils do not like the wireless type, so you’ll have to opt for the wired ones. Speak to your local authority about this and the decision might be made for you.

Otherwise, both are acceptable, but to answer which is better depends on one principal question: Is it a complete refurbishment where you can rip up the carpets and floorboards or are you looking to fit them retrospectively?

  • If it’s a refurbishment, opt for wired
  • If you’re retrofitting, opt for wireless

In terms of cost, there isn’t going to be that much of a difference once you factor in the labour.

Radio Frequency Interlinked



Wired Interlinked



To read more articles like this one, please visit our Home Alarms page.