How much does it cost to install a carbon monoxide detector? [March 2025]

What other factors affect the cost of installing a carbon monoxide detector?
 

As well as the type of alarm you opt for and where you live, there are a few more factors that need to be considered when determining the final cost of installing a CO detector. 
 

1. When you book
 

Electricians will charge a higher rate during unsociable hours, such as early mornings, in the evenings, the weekends and during bank holidays. You’ll also find they’ll charge a higher rate for same-day callouts and next-day bookings. 

2. Additional work 
 

If you're looking to get a hard-wired CO alarm fitted, and you don't already have an existing electrical box, you're electrician will need to cut a hole into your wall to install one and hook into the wires. This can hike up the price of your total alarm installation by a few hundred pounds. You may also need to account for any paint touch-ups to the area after the work is done.
 

3. Whether you book with an independent electrician or established company

Independent electricians typically charge lower hourly rates than larger, well-established tradesperson companies. However, the higher costs of professional electrician services often come with several advantages. For instance, you’ll usually have more flexible booking options, on-the-day callouts, and support from experienced customer service teams if anything goes wrong. These services, like Housekeep, often guarantee their work for 72 hours, which means they’ll come back out to fix any problems free of charge. 

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What are the different types of carbon monoxide detectors? 
 

There are two main types of CO detectors on the market - battery-operated and hardwired. 

A battery-operated alarm functions exactly as the name suggests. You’ll need to stay on top of replacing its batteries for it to work, which can be as often as every 6 months. Hardwired CO alarms are connected straight into your mains supply. Of course, these come with higher installation costs as they require an electrician to hook them to your home's electrical system. If you're home already has a hard-wired smoke alarm system, you can often just intregrate the alarms together. 

Smart CO detectors like NEST alarms have more advanced features such as app-based alerts, which notify you of CO dangers directly on your phone. These smart detectors typically come in both battery and hardwired options.

You might also come across plug-in carbon monoxide detectors; however, these are generally not recommended. In a power outage, these alarms will fail to operate, unlike battery-operated or hardwired detectors, which are designed to function even without electricity. Hardwired CO detectors are particularly reliable, as they have a built-in long-life lithium battery which acts as a power backup incase of an outage.
 

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Why are carbon monoxide detectors important?

Carbon monoxide is a colourless, odourless and tasteless gas produced by incomplete combustion. This can happen when carbon-based materials, like wood, gas, oil and coal don’t burn completely due to a lack of oxygen. [1] Exposure to carbon monoxide can be fatal, earning its title as the ‘silent killer’.  According to the National Institute of Health and Care Excellence, CO poisoning accounts for around 40 deaths per year in the UK. [2]

Carbon Monoxide detectors are devices that can detect signs of CO in the air, sounding an alarm to alert those living in the home. As it’s tricky to detect carbon monoxide, CO alarms an important tool that can save lives.  
 

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Is it a legal requirement to have a carbon monoxide detector fitted? 

As per the amended Smoke and Carbon Monoxide Alarm Regulations 2022, it’s a legal requirement for all landlords to ensure a carbon monoxide alarm is in every room where a fixed combustion appliance is installed. It’s also the landlord's legal responsibility to fix or replace this alarm if found to be faulty. The only exception is if you have a gas cooker, as these produce only minimal CO if used correctly. [3]

Of course, even if you’re a homeowner or have a gas cooker, it’s best practice to get a detector fitted for peace of mind. 

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How often should carbon monoxide detectors be replaced?

Battery-operated carbon monoxide detectors should be replaced every 5 years, though the batteries may wear out sooner and should be replaced as needed. Hardwired alarms typically last a bit longer, usually around 5-7 years.

Most CO alarms will alert you when they reach the end of their life by beeping every 30 seconds. They may also emit a chirping sound when the battery needs replacing.
 

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Where should carbon monoxide alarms be fitted?
 

Whilst there aren’t any strict regulations stating where exactly carbon monoxide alarms need to be fitted, it’s strongly recommended to place them in any room with a fixed combustion appliance installed, around 1-3 metres from the appliances. It can be placed either on the wall, or placed on a shelf but it should be fitted at head height. [1]

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What other steps can you take to protect your home from a carbon monoxide leak?
 

As well as fitting a working carbon monoxide alarm, you should ensure that your boiler and all fuel-burning appliances are serviced by a gas safety engineer once a year. [4]  A great starting point for finding a certified professional is the the Gas Safe Register directory. Since it’s a legal requirement for all engineers to be registered before working on gas appliances, hiring through this directory guarantees they are fully qualified, giving you peace of mind. Or you could book with a professional tradesperson service, such as through the Housekeep website.

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Can I install a carbon monoxide detector myself?

You can actually install a carbon monoxide detector yourself. Just make sure to follow the manufacturer's instructions on how and where to install. You should always buy your CO detector from a reputable store, and ensure that the device bears a recognised British or European approval mark, and is compliant with British Standard EN 50291. [5]

For complete peace of mind, you should consider hiring a qualified electrician to install your carbon monoxide alarm instead. A professional electrician can source a reliable CO detector from trusted local suppliers and use their expertise to position and install it in the most effective place possible. This is expecially important if you're installing a hard-wired alarm, as handling wiring and electricity can be dangerous if not done correctly.
 

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Where can I find an electrician to install my carbon monoxide detector?
 

There's plenty of ways to find an electrician to fit a carbon monoxide alarm. However, any electrician you hire must be 'qualified' and 'competent', which essentially means they are a member of a trusted trade body, such as the NICEIC or the Electrical Competent Person Scheme. For added peace of mind, you can even hire an electrician straight from their online directories. You could also check out local groups on social media or community boards for local recommendations. If any of your friend and family have had some electrical work done recently, you could ask them for recommendations too. 

Alternatively, you could book through a professional tradesperson service, which offers additional benefits like same-day call-outs and responsive customer support. Many services, like Housekeep, also guarantee their work for 72 hours, ensuring they’ll return to fix any issues free of charge. You can get a quote directly from the Housekeep website - just let us know what needs doing, and we’ll send a fully qualified electrician at a time that suits you.

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Sources 
 

1. GOV: Carbon monoxide: general information
2. NICE: Carbon monoxide poisoning
3. Gov: Smoke and Carbon Monoxide Alarm (Amendment) Regulations 2022: guidance for landlords and tenants
4. London Fire Brigade: Carbon monoxide safety 
5. Safelincs: British Standards for CO Alarms Explained