By Emily Rivers
Last updated 5th May 2023

Carbon Monoxide Alarm Installation Cost Guide 2023

Carbon monoxide detector alarms are vital if you have a fuel-burning appliance like a gas boiler or wood burner. A battery-powered carbon monoxide detector can cost as little as £20, whereas mains-powered alarms cost an average of £175 to be installed. Find out more about how much carbon monoxide alarm installation will cost in our guide.

How much does it cost to install a carbon monoxide alarm?

How much it costs to install a carbon monoxide alarm will depend on the type of alarm and how many of them you want, where you are in the country and the experience level of your electrician. Here are the average costs of carbon monoxide alarms in the UK:

Alarm type

Average cost

Battery-powered carbon monoxide alarm (supply only)

£20

Battery-powered carbon monoxide alarm installation 

£80

Mains-powered carbon monoxide alarm (supply only)

£100

Mains-powered carbon monoxide alarm installation

£175

HaMuch has a large database of hourly and daily rates for electricians across the country, so make sure you take a look at our job tables to get a more accurate idea of how much an electrician will charge for labour in your area.

Cost to fit a carbon monoxide alarm

Why do I need a carbon monoxide alarm?

Carbon monoxide alarms, sometimes called CO alarms or detectors, alert you if there are dangerous levels of carbon monoxide in the alarm's vicinity. Carbon monoxide (CO) is an unscented, colourless gas that is produced when a carbon-carrying fuel, such as coal, wood, natural gas or charcoal, doesn't completely burn.

Because it is unscented and colourless, you won't know if your appliance is releasing carbon monoxide without a CO alarm. If you live with a carbon monoxide leak for a prolonged period of time, you can become seriously ill or even die. Symptoms of carbon monoxide poisoning include:

  •   Flu-like symptoms, like headache, blocked nose and aching joints
  •   Nausea or vomiting
  •   Dizziness
  •   Confusion
  •   Chest pain
  •   Shortness of breath

 These symptoms may come and go, and get better when you leave the area where the faulty appliance is located then get worse when you return.

Carbon monoxide poisoning is a very serious condition, but it can be prevented with a relatively inexpensive carbon monoxide alarm.

Types of CO alarm

Battery-powered carbon monoxide detector

Battery-powered carbon monoxide alarms are the cheapest type of alarm and the easiest to install. They can cost as little as £20 and are a great budget-friendly option because you can fit them yourself. Some alarms may be freestanding, while others will need fixing to a wall. Some will just make a sound if it detects a dangerous level of CO in the air, while others may show the parts-per-million (ppm) it can detect.

Make sure you check your carbon monoxide detector’s battery regularly, and change it once per year. If you notice a ‘chirp’ coming from the alarm even after you’ve changed the battery, you should replace the alarm.

Mains-powered carbon monoxide alarms

Mains-powered carbon monoxide detectors are wired into your electricity supply and are usually supported by a backup battery. They are more expensive than battery-powered alarms, but they are also more reliable. There’s no need to check a mains-powered CO detector because as long as your electricity supply is on, your carbon monoxide alarm will be working.

Because a mains-powered carbon monoxide alarm requires connecting to your electrics, you should get an electrician to install it for you. Always use an electrician that’s registered with a trade body like NAPIT, ELECSA or NICEIC, and get at least three quotes.

Bear in mind that your home’s wiring will need to be in good condition to withstand a new mains-powered carbon monoxide alarm installation. If your electrician is concerned, they might suggest that you get an Electrical Installation Condition Report (EICR) completed, which will increase the cost. If any issues are found, you may have to replace your consumer unit before it’s safe to install a mains-powered CO detector.

Where is the best place to put a carbon monoxide detector?

According to Cadent, you should ideally have a carbon monoxide detector on each floor of your house and in the same room as any fuel-burning appliance, such as a boiler or stove. The alarm should be at head height, but it could be on a shelf - it doesn’t have to be fixed to a wall. It should also be at least 15cm from the ceiling. 

You should also ensure that your carbon monoxide alarm is at least a metre away from your boiler, oven or other fuel-burning appliance. It also shouldn’t be placed behind furniture, in a cupboard or near external doors as this could stop it from working correctly.

Do the fire brigade install carbon monoxide alarms?

Most fire brigades will carry out ‘Safe and Well’ visits for the vulnerable, the elderly or some people on benefits. They may install a carbon monoxide alarm for free, but you may have to meet certain criteria to be eligible.

Are carbon monoxide detectors required by law in the UK?

For homeowners, carbon monoxide detectors are not required by law in the UK. However, if you have a fuel-burning appliance, it makes sense to install one to keep you and your loved ones safe from CO poisoning.

If you’re a private landlord, you are bound by law to fit carbon monoxide alarms where necessary, and failure to do so can lead to a fine of up to £5,000.

If you want to get a mains-powered carbon monoxide alarm fitted, post your job on HaMuch to get a range of quotes from registered electricians in your local area.


Estimates for common electrician jobs;

Rates for other trades

Install carbon monoxide alarm cost in the UK
Install carbon monoxide alarm cost in the UK (excluding VAT or callout charges)
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