Carbon Monoxide Alarms: Rental Law England 2025

Yes, carbon monoxide alarms are a legal requirement in English rental properties. Since 1 October 2022, landlords must install at least one alarm in any room with a fixed combustion appliance — a gas boiler, gas fire, wood burner, or similar. Failure to comply can result in a £5,000 fine per property, enforcement action from the local housing authority, and liability if a tenant is harmed.

That's the headline. Now let me walk you through exactly what the law says, where alarms need to go, what type you need, and what I see going wrong in the rental sector out here in the North East.

The Short Answer: Yes, Carbon Monoxide Alarms Are a Legal Requirement

Since October 2022, England's rental properties have been covered by the Smoke and Carbon Monoxide Alarm (Amendment) Regulations 2022, which updated the original 2015 regulations. This isn't optional guidance — it's law. Landlords who own or let properties in the private rented sector must install carbon monoxide alarms. The responsibility is clear, the penalties are real, and I've seen enforcement action happen locally.

Which Regulation Covers Carbon Monoxide Alarms in Rental Properties?

The relevant law is the Smoke and Carbon Monoxide Alarm (England) Regulations 2015, as amended by the Smoke and Carbon Monoxide Alarm (Amendment) Regulations 2022.

The 2022 amendment tightened the rules. Previously, landlords had some flexibility; now the rules are stricter and apply to more situations. The update also aligned these requirements with the Electrical Safety Standards in the Private Rented Sector (England) Regulations 2020, meaning your CO alarm obligations tie directly into electrical safety checks (more on that below).

The law applies to the private rented sector — houses, flats, and HMOs let to tenants. It does not apply to owner-occupied properties, social housing landlords (though they have separate duties), or temporary holiday lets.

Exactly Where Must a Carbon Monoxide Alarm Be Fitted in 2025?

This is where I see the most confusion.

You must fit at least one carbon monoxide alarm in any room with a fixed combustion appliance.

Fixed combustion appliances include:

• Gas boilers (the most common)
• Gas fires
• Wood burners and solid fuel stoves
• Oil boilers
• Any other fixed heating or cooking appliance that uses fuel

If your property has a boiler in a kitchen or utility room, that room needs a CO alarm.

If there's a gas fire in the living room, that room needs one.

You do not need a CO alarm in a room without a combustion appliance, even if the building has one elsewhere. For example, if the boiler is in a sealed cupboard in the kitchen, you fit the alarm there — not in every bedroom.

In practice, in properties I inspect across Tyne and Wear and Northumberland, most have a single alarm near the boiler, or in the main living space if there's a gas fire. That's usually sufficient.

Important caveat: Your alarm must be positioned according to the manufacturer's instructions, which typically means at least 300 mm away from the appliance and in a spot where it can draw air freely. Don't hide it in a cupboard or behind a curtain. I've seen that happen, and it defeats the purpose entirely.

What Type of Carbon Monoxide Alarm Is Legally Acceptable?

The alarm must comply with BS EN 50291, the British Standard for carbon monoxide alarms for domestic use. Any alarm you buy should state this on the packaging.

Battery-operated or mains-wired? Both are legal, provided they meet the standard. However, the 2022 regulations introduced a recommendation (not yet a hard requirement for all properties) that alarms should be mains-wired with battery backup where feasible, to reduce the risk of batteries failing and leaving tenants unprotected. In new installations or major works, I usually fit mains-wired alarms to a dedicated circuit or spur, as they're more reliable long-term.

Battery-operated alarms are cheaper (typically £20–£50) and easier to install, but you or the tenant must remember to test them monthly and replace batteries annually. That's a hassle, and it's one reason I lean toward mains-wired where possible.

Interlinked alarms? The regulations don't require alarms to be interlinked to smoke alarms, though many modern alarms are. Interlinked systems are nice to have but not mandatory for CO compliance alone.

Who Is Responsible – Landlord or Tenant?

The landlord is responsible for installation and ensuring the alarm is present at the start of the tenancy. You must fit it and keep it in good working order. The tenant is responsible for testing it monthly and reporting faults — but the burden of ensuring it's there and functional falls to you.

In practice, I advise landlords to:

1. Install the alarm before the tenant moves in.

2. Document it (photo, completion date, model number).

3. Provide the tenant with written instructions on how to test it monthly.

4. Include it in your tenancy agreement or a separate safety checklist.

5. Check it during routine visits or inspections.

If a tenant disables the alarm or removes batteries and doesn't report it, that's partly on them — but you'll still need to show you installed it correctly and communicated the responsibility clearly.

What Happens If a Landlord Fails to Comply?

This is where it gets serious. The consequences are:

• Fixed penalty notice: £5,000 per property (issued by the local housing authority).
• Criminal prosecution: If the breach is more serious or you ignore a remedial notice, you can be prosecuted and face a fine of up to £50,000 or unlimited fine in some cases.
• Enforcement action: The local housing authority can issue a Remedial Notice requiring you to install an alarm within a set timeframe. Failure to comply can result in prosecution or the authority arranging installation and billing you for it.
• Liability: If a tenant suffers carbon monoxide poisoning and you failed to install an alarm, you face civil liability — potentially significant damages.

I know of cases locally where landlords have been hit with enforcement action, especially when local authorities conduct proactive inspections. It's not a grey area.

How Carbon Monoxide Rules Connect to Your Electrical Safety (EICR)

Here's the overlap many landlords miss: the Electrical Installation Condition Report (EICR) and carbon monoxide compliance are now linked under the 2020 Electrical Safety Regulations.

If your CO alarm is mains-wired, it must be connected safely to your electrical installation. Your EICR (which you're legally required to obtain every five years for lettings) should document that any mains-wired CO alarm is installed properly — circuit, earth, overload protection, all correct.

If you skip the CO alarm but have an EICR done, a thorough electrician will note the missing alarm as a non-compliance. If you fit an alarm but the electrical connection is dodgy, that's also a problem.

Checklist: What Landlords Must Do Before a New Tenancy

• [ ] Identify all rooms with fixed combustion appliances.
• [ ] Install at least one BS EN 50291 compliant carbon monoxide alarm per room (or in the space where the appliance is located).
• [ ] Take a photograph showing the alarm installed.
• [ ] Record the alarm model number, serial number, and date fitted.
• [ ] If mains-wired, ensure the circuit and earthing are correct (inspect this as part of your EICR).
• [ ] Provide the tenant with written test instructions and a log sheet for monthly testing.
• [ ] Mention the alarm in the tenancy agreement or safety information provided.
• [ ] Plan to check the alarm during inspections or at least annually.

FAQ: Carbon Monoxide Alarms in Rental Properties England 2025

Do I need a carbon monoxide alarm if my rental property only has a gas boiler?

Yes. A gas boiler is a fixed combustion appliance, so the room containing it (typically the kitchen or utility room) must have a CO alarm. No appliance, no exemption.

Can I use a battery-operated carbon monoxide alarm or does it have to be mains-wired?

Both are legal, provided they meet BS EN 50291. Battery-operated alarms are cheaper and easier to install, but require monthly testing and annual battery replacement — which often falls to you in practice. Mains-wired alarms are more reliable long-term, but require proper electrical installation.

Who has to test the carbon monoxide alarm – me as the landlord or my tenant?

Legally, you (the landlord) must ensure the alarm is present and in good working order. The tenant should test it monthly, but if they don't report a fault, you're still liable if something goes wrong. I recommend writing down the testing responsibility in your tenancy documentation so it's clear.

What fine can a landlord receive for not having a carbon monoxide alarm fitted?

A fixed penalty notice is £5,000 per property. Criminal prosecution can result in fines up to £50,000 or unlimited in serious cases. Don't take the risk.

Does the carbon monoxide alarm law apply to HMOs and social housing as well as standard rentals?

Yes, it applies to HMOs (houses in multiple occupation) in the private rented sector. Social housing providers have separate legal duties but must also provide CO alarms. It does not apply to owner-occupied properties or holiday lets.

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If you're a landlord in North East England and need a carbon monoxide alarm installed, tested, or want to check your compliance before the next tenancy starts, [get in touch with Energy North Ltd](https://energynorth.uk). We're qualified electricians who work with landlords regularly and can handle the installation and any electrical work needed to keep you legal and your tenants safe.