Smoke and carbon monoxide alarm rules in Wales

What the rules require in rented homes

Under the Renting Homes framework in Wales, a dwelling let as a home must be fit for human habitation, and that includes specific fire and carbon monoxide provisions. Smoke alarms must be mains powered and interlinked, with at least one on every storey of the property. Carbon monoxide alarms are required in every room containing a gas, oil or solid fuel appliance.

Interlinked is the word that catches landlords out. Battery alarms bought in a supermarket do not satisfy the requirement, and neither does a single mains alarm in the hall. When one sounds, they all have to sound, which is the entire point at three in the morning with bedroom doors closed.

• Mains powered smoke alarms, interlinked, one per storey minimum
• Carbon monoxide alarms in rooms with fuel burning appliances
• Alarms must be in working order at the start of each occupation
• The electrical installation must also be inspected at least every five years

Where alarms should go

Circulation space on every storey is the baseline: the hall on the ground floor and the landing above. Heat alarms are used in kitchens rather than smoke alarms, because cooking sets smoke alarms off and an alarm that gets silenced is worse than no alarm. Living rooms with an open fire or a wood burner are commonly covered too.

Position matters. Ceiling mounted, away from corners, away from the immediate vicinity of bathroom doorways where steam causes false alarms, and away from anywhere a draught will carry smoke past rather than into the sensor. Carbon monoxide alarms follow the manufacturer's guidance relative to the appliance.

Owner occupiers

If you own and live in your home, the Renting Homes duties do not apply to you. The specification still does as a matter of good sense, and it is what fire and rescue services recommend. Interlinked mains alarms with battery backup on every storey, a heat alarm in the kitchen, and carbon monoxide alarms wherever there is a fuel burning appliance.

The upgrade is not expensive when done as part of other work. If you are having a consumer unit changed, a rewire, or a loft conversion, adding an interlinked alarm system at the same time costs very little extra because the access is already paid for.

• Hall and landing as a minimum, ceiling mounted
• Heat alarm rather than smoke alarm in the kitchen
• Carbon monoxide alarm with any gas, oil or solid fuel appliance
• Battery backup so the system survives a power cut

Testing, maintenance and replacement

Test every alarm monthly using the test button. It takes a minute and it is the only way to know the sensor and the sounder both still work. Vacuum the units occasionally, because dust is the most common cause of both false alarms and failures to detect.

Alarms have a working life, typically around ten years for smoke alarms and often shorter for carbon monoxide units. That life is printed on the unit. Replace on date rather than on failure, because a sensor that has degraded does not announce itself. Never remove a battery or disconnect an alarm to stop nuisance sounding: relocate it or fit the right type instead.

Getting it installed

Mains powered interlinked alarms are fixed wiring work. They need a supply, they need to be interconnected, and the installation should be tested and certified in the usual way. Wireless interlink between mains powered units is a legitimate solution and removes the need to run interconnect cable through finished ceilings, which makes retrofitting far less invasive.

For landlords across Merthyr Tydfil, Cardiff and Swansea, the sensible approach is to do alarms at the same time as the five yearly EICR. One visit, one set of paperwork, both duties covered, and you have documented evidence that the alarms were working at the start of the occupation.