Carbon Monoxide Alarm — Marylebone
Carbon monoxide alarm installation in Marylebone
Gas Safe engineers supplying and fitting CO alarms in Marylebone, Westminster. From £65 per alarm. Fully compliant with the Smoke and Carbon Monoxide Alarm (Amendment) Regulations 2022. Same-day appointments available.
The 2022 law explained
2022 Regulations: what landlords in Marylebone must do
The Smoke and Carbon Monoxide Alarm (Amendment) Regulations 2022 extended landlord obligations across all of England from 1 October 2022. Every private rented property in Marylebone must now have a CO alarm in every room that contains a fixed combustion appliance — in practice, every room with a gas boiler, gas fire, or gas cooker.
For most Marylebone properties this requires alarms in the boiler location, the kitchen (if there is a gas hob or oven), and any reception room with a gas fire. A local housing authority in Westminster can issue a remedial notice and fine of up to £5,000 per property if a landlord fails to comply after being given a 28-day opportunity to remedy the breach.
Alarms must be tested at the start of each new tenancy and replaced when they fault or expire. Our Gas Safe engineers serving Marylebone carry compliant sealed battery and mains-powered alarms in stock and can install, test, and certify on the same visit.
Alarm types and what to do if one sounds
Sealed battery vs mains-powered — and what to do if an alarm sounds
For most Marylebone rental properties, sealed 10-year battery CO alarms meeting BS EN 50291-1 are the most practical choice. No rewiring is required and the unit is replaced as a whole at the end of its stated life — typically 7-10 years. Mains-powered alarms with battery backup are required where the property specification or licence conditions demand an interlinked system.
If a CO alarm in your Marylebone property sounds: open all windows and doors immediately, evacuate everyone including pets, call the National Gas Emergency Service on 0800 111 999 from outside the property, and do not re-enter or use any gas appliances until a Gas Safe engineer has inspected and given the all-clear. Carbon monoxide is odourless and colourless — symptoms of poisoning include headache, dizziness, and nausea.
Homeowners in Marylebone are not legally required to fit CO alarms under the 2022 Regulations, but the Health and Safety Executive strongly recommends one in every room with a gas appliance. Our engineers can advise on the right protection for owner-occupied properties at the same time as a landlord compliance visit.
Our services
Carbon monoxide alarm services
Single CO alarm installation
Supply and fit of a mains-powered or sealed battery CO alarm in a single room containing a gas appliance. Compliant with BS EN 50291-1. Certificate of installation provided.
From £65
Multi-room CO alarm package
Installation of CO alarms in all rooms with gas appliances across the property — boiler cupboard, kitchen, living room. Discounted rate per alarm when fitting three or more.
From £55/alarm
Combined smoke + CO alarm
Supply and fit of a combined smoke and carbon monoxide alarm — one device covering both legal obligations. Ideal for rental properties with limited ceiling space.
From £120
Alarm testing and servicing
Functional test of existing CO alarms including sensor self-check, audible test, and expiry date verification. Report issued confirming compliance or replacement needed.
From £45
Interlinked alarm system
Wireless interlinked CO and smoke alarm system — when one alarm triggers, all sound throughout the property. Recommended for HMOs and multi-floor properties.
From £180
Landlord compliance certificate
Full written compliance report confirming CO alarms are fitted in all required rooms, alarm types meet 2022 Regulations, and all devices have been tested on the date of visit.
Included with install
Transparent pricing
Carbon monoxide alarm pricing
Single CO alarm installed
From £65
Supply, fit, and test. BS EN 50291-1 compliant device.
Combined smoke + CO alarm
From £120
One device covering both legal requirements.
Multi-room package (3+ alarms)
From £55/alarm
Whole-property compliance in a single visit.
All prices include supply of alarm, installation, functional test, and written confirmation of compliance. No VAT on domestic installations.
Book today
CO alarm installation in Marylebone — same-day available
Landlords have been legally required to fit carbon monoxide alarms in every room with a gas appliance since October 2022. Non-compliance risks fines of up to £5,000 per property. Book a Gas Safe engineer in Marylebone today.
Book CO alarm installationCommon questions
Carbon monoxide alarm Marylebone: frequently asked
What does the Smoke and Carbon Monoxide Alarm (Amendment) Regulations 2022 require?
Since 1 October 2022, all private landlords in England must fit a carbon monoxide alarm in every room used as living accommodation that contains a fixed combustion appliance — including rooms with gas boilers, gas fires, and gas cookers. The alarm must be in working order at the start of each new tenancy.
Where must carbon monoxide alarms be placed in a Marylebone property?
A CO alarm must be fitted in every room in your Marylebone property that contains a gas appliance. For most properties this means the boiler cupboard or utility room, the kitchen (if there is a gas cooker), and any room with a gas fire. Alarms should be positioned at head height, at least 1 metre from the appliance.
What type of carbon monoxide alarm is compliant with the 2022 Regulations?
The Regulations require alarms compliant with BS EN 50291-1. Both mains-powered and sealed 10-year battery alarms are acceptable. Alarms must be tested at the start of each tenancy and replaced before the manufacturer's stated expiry date.
Can I test the carbon monoxide alarm myself?
The test button confirms the sounder and battery work but does not verify the electrochemical sensor. A full sensor verification requires calibrated equipment. Landlords should have alarms professionally inspected at tenancy renewal. Sensors expire after 7-10 years regardless of CO detections.