Propertymark is urging all tenants and landlords to take five minutes to check their carbon monoxide (CO) alarms and heating systems to keep their homes safe this winter.

Carbon monoxide is known as the “silent killer” because it has no smell, taste, or colour, yet just a small amount can be fatal. Each year, hundreds of people in the UK are admitted to hospital with CO poisoning, and many incidents are preventable with simple checks and maintenance.

Ahead of Carbon Monoxide Awareness Week next week (17–23 November) Nathan Emerson, chief executive of Propertymark, says: “Carbon monoxide can strike without warning, and it doesn’t matter whether you own your home or rent it; everyone needs to take this seriously. A working alarm costs less than a takeaway meal but could save your life.”

Carbon monoxide is produced when fuels like gas, oil, wood, or coal don’t burn properly. Faulty boilers, gas fires, cookers, or blocked flues and chimneys are common culprits. Because CO can’t be seen or smelt, the first signs are often headaches, dizziness, nausea, confusion, or breathlessness, symptoms that can easily be mistaken for flu or tiredness.

If you suspect CO poisoning, turn off all appliances, get fresh air immediately, and call 999.

Propertymark’s safety tips for agents to pass to landlords and tenants in England:

1. Test your carbon monoxide alarm

• Press the test button once a month to make sure it’s working.
• Replace the batteries when needed, or upgrade to a mains-powered model with a backup battery.
• Every home with a fuel-burning appliance should have a CO alarm in that room.

2. Know where to fit it

• Place the alarm at head height, around one to three metres from the appliance.
• Avoid corners, cupboards, or directly above sources of steam.

3. Get your appliances serviced annually

• Arrange for a Gas Safe registered engineer to check boilers, fires, and cookers each year.
• Ask to see the engineer’s ID and record the service date.

4. Never block air vents or flues

• Good ventilation prevents dangerous gas build-up.
• If you spot soot stains, yellow flames, or your pilot light keeps blowing out, call for a safety inspection immediately.

5. Know the law if you rent in England

• Landlords are legally required to install carbon monoxide alarms in every room with a fixed fuel-burning appliance (such as a gas boiler, fire, or wood burner). They must also check that these alarms are working properly at the start of each new tenancy.
• Managing agents, where appointed, are responsible for ensuring these safety checks are carried out and properly documented as part of ongoing property management duties.
• Tenants should expect their landlord or agent to:
  – Provide confirmation that all alarms have been tested before move-in.
  – Arrange annual gas safety inspections and supply tenants with a valid Gas Safety Certificate (CP12) within 28 days of the check.
  – Respond promptly to reports of faulty alarms or suspected CO issues.
  – Keep clear records of all maintenance, testing, and servicing carried out.
• Tenants also have responsibilities to test alarms regularly, keep ventilation clear, and report any faults or safety concerns immediately.
• Rent payments cover not only the use of the property but also the landlord’s obligation to maintain it in a safe and habitable condition, including functioning CO alarms and safe gas appliances.

Nathan Emerson adds: “A few quick checks can save lives. We’re urging everyone to take five minutes during Carbon Monoxide Awareness Week to test their alarm, ensure your appliances are being serviced, and remind loved ones to do the same. Safety at home starts with awareness.”