Carbon Monoxide Safety for Holiday Lets: What Every Owner Must Know

Carbon monoxide is called the silent killer for good reason. It is colourless, odourless and impossible for a guest to detect without a working alarm. Exposure can cause headache, dizziness, nausea, confusion, collapse and death.

Holiday let owners have a legal duty to protect guests, but compliance should be the starting point rather than the complete safety plan. Correct alarms, clear instructions, regular testing and properly serviced appliances work together. This guide explains what the law requires in England and what responsible practice looks like beyond the minimum.

The legal position

The Smoke and Carbon Monoxide Alarm (England) Regulations 2015, as amended in 2022, require a carbon monoxide alarm in any room used as living accommodation that contains a fixed combustion appliance. Gas cookers are specifically excluded from that definition.

For holiday accommodation, owners must also consider the wider fire-safety duties applying to paying guests and the particular way the property is occupied. Do not assume that a short stay or furnished-holiday-let status removes the need for an alarm.

The requirement covers appliances such as gas boilers, gas fires, log burners, open fires and oil-fired boilers when they are in living accommodation. A compliant alarm must be present and in proper working order. Local authorities can impose a remedial notice and financial penalties of up to £5,000 for non-compliance.

Owners should retain evidence of installation, testing, servicing and any replacement. A photograph of each alarm in position, a dated testing log and service documents create a clear record that safety has been actively managed.

What counts as a fixed combustion appliance?

A gas boiler counts, whether it heats radiators, hot water or both. A gas fire also counts. If either sits in a kitchen, bedroom or living area used by guests, that room needs an alarm in an appropriate position.

A log burner or wood burner counts because it burns solid fuel and can produce carbon monoxide if combustion or ventilation is poor. An open fireplace counts too, even where it is used only occasionally. Owners should not remove the alarm outside winter or assume guests will never light the fire.

An oil-fired boiler is another fixed combustion appliance. Its fuel differs from gas, but incomplete combustion still creates risk. A boiler in an attached utility room, cupboard or unusual layout may require professional advice on the right alarm location.

Gas cookers are specifically excluded from this particular alarm requirement. Good practice is still to fit a carbon monoxide alarm where gas cooking is present, especially in an open-plan space. The cost is small and the alarm adds another layer of protection.

Choose and position the right alarm

Battery-operated alarms can comply, provided they meet the correct standard and remain in working order. Sealed long-life battery units reduce the risk of a guest removing ordinary batteries. Mains-wired alarms with battery backup are preferable during a renovation or where a qualified electrician can install them appropriately.

Choose an alarm carrying the British Standard Kitemark for BS EN 50291. Check that it is intended for domestic premises and note the replacement date printed by the manufacturer. Carbon monoxide sensors have a finite life even when the test button still works.

Follow the manufacturer's instructions for positioning. General guidance places an alarm approximately one to three metres horizontally from the appliance, at head height for the way the room is used and away from corners, windows, vents or enclosed cupboards. Do not rely on a convenient shelf if the instructions require wall or ceiling mounting.

Test every alarm before every guest stay and record the check. The test button confirms power and sounder operation; it does not replace servicing or end-of-life replacement. Check for damage, obstruction and any warning indicators during each turnover.

Tell guests exactly what to do

The welcome guide should identify where each carbon monoxide alarm is located and explain what it sounds like if activated. Guests should be able to distinguish an emergency alarm from a low-battery chirp without searching online.

Instructions must be direct: leave the property immediately, make sure everyone gets outside and do not go back in. Call 999 if anyone has symptoms or there is an immediate danger. Contact the National Gas Emergency Service on 0800 111 999 where gas is involved, then call the property's emergency contact.

Do not tell guests to silence the alarm, open a window and continue the stay. Ventilation may reduce the reading without removing the cause. The property should remain empty until the relevant emergency service or competent engineer confirms it is safe.

Display concise instructions inside as well as in a digital guide. An emergency is not the moment to rely on a phone signal, app login or a long manual.

Regular servicing is the best prevention

Alarms provide essential warning, but preventing carbon monoxide is better. Gas boilers and other gas appliances should be inspected and serviced annually by a Gas Safe registered engineer. Keep the certificate, service report and any repair records.

Log-burner and open-fire flues should be swept at least annually, and more often where use or fuel type requires it. Use a competent chimney sweep, inspect the appliance and ventilation, and provide guests with suitable dry fuel and clear operating instructions.

Oil-fired boilers should also be serviced annually by a suitably qualified technician. Never delay investigation of soot, staining, unusual smells, pilot-light changes or repeated alarm activation.

Our broader guide to holiday let fire-safety compliance explains how alarm testing, risk assessment and evacuation planning fit into the complete safety system.

Our approach at Full Bed Hosts

Carbon monoxide detector testing forms part of the pre-stay check for every property we manage. We confirm that required alarms are installed in suitable locations, record regular tests and track manufacturer replacement dates.

We also monitor appliance servicing so gas, oil and solid-fuel systems are attended on schedule. Our holiday let management service helps owners turn legal duties into repeatable operational checks rather than relying on memory. Owners should still obtain property-specific advice from competent safety professionals where requirements or positioning are unclear.