Smoke and Carbon Monoxide Alarm Rules Every Landlord Should Know

The alarms on the ceiling can feel like a small detail next to everything else you sort as a landlord. They are not. Since the rules were updated in October 2022, there is a clear duty on landlords in England around smoke and carbon monoxide alarms, and a council can fine you up to £5,000 per property if you get it wrong. It is worth a few minutes to check yours are right.

Smoke alarms: one on every floor

The rule itself is simple. You need at least one smoke alarm on every storey of the property that someone uses as living space. A hallway and a landing are the obvious spots, but the bit landlords miss is the odd room, like a loft that has become a bedroom or a basement someone uses as a study. If people live, sleep or cook on that floor, it needs an alarm.

Alarms usually go on the ceiling, out in the circulation space such as a hall or landing, because that is where smoke travels first. Fitting them tight into a corner or right beside a kitchen or bathroom tends to cause false alarms, so placement does matter.

Carbon monoxide alarms and the 2022 change

This is where the rules got wider. You now need a carbon monoxide alarm in any room with a fixed combustion appliance, so a gas boiler, a wood burner or an open fire. Gas cookers are the one exception. Before 2022 the duty only covered solid fuel like a coal fire, so plenty of properties with gas boilers were technically fine then and are not now.

A CO alarm wants to sit at head height, roughly one to three metres from the appliance. Too close and it nuisance-trips, too far and it reacts slowly.

Checking they work at the right time

Here is the timing that catches people out. On the first day of a new tenancy, you have to make sure every alarm is working. Not last month, not “it was fine when we fitted it”, but on the day the tenant moves in. After that, the tenant is expected to test them during the tenancy, and if they tell you one has stopped working you need to repair or replace it as soon as you reasonably can.

Keep a note of that start-of-tenancy check. If a dispute ever comes up, a dated record is worth a lot.

Battery or mains wired?

The regulations let you use either, as long as the alarm actually works, so battery-only units are legal. That said, sealed ten-year alarms and mains-wired interlinked systems are far more reliable. There is no flat battery to worry about, and when they are linked, one going off sets them all off. In a house of multiple occupation the bar is higher again, and building standards usually point you towards mains interlinked alarms on a proper grade of system.

Where landlords tend to slip up

• Leaving it to the tenant’s own plug-in alarm, which you have no control over
• Fitting nothing on a loft or cellar floor that is actually lived in
• No carbon monoxide alarm in the room with the boiler
• No record that the alarms were tested when the tenancy started

If you are not sure your setup matches the current rules, it helps to have an electrician look at where the alarms sit and whether interlinked mains units make sense for your property. We cover this as part of our work with landlords across Liverpool and the North West, and you can read more about our fire alarm testing as well.

Common questions

Do smoke alarms have to be mains wired in a rented house?

Not for a standard single let. The law asks for a working alarm on each living storey, and battery units are allowed. Mains interlinked alarms are the safer bet and are often expected in HMOs, but for an ordinary house or flat the choice is yours as long as they work.

Who tests the alarms once someone has moved in?

That falls to the tenant during the tenancy. Your job is to have them working on day one and to fix any alarm the tenant reports as faulty. It is sensible to remind tenants to test monthly, since a dead alarm helps nobody.

What happens if I ignore it?

The council can serve a remedial notice, and if you do not act they can fine you up to £5,000 for that property. More to the point, working alarms are what give people the seconds they need to get out.