Smoke Detectors vs Heat Detectors: Which Goes Where in a London Home

Fire alarms in London homes are not one size fits all. A smoke alarm in the wrong place causes false alarms every time someone makes toast, and a heat alarm in a hallway may react too late. Knowing which type goes where makes a home safer and stops tenants pulling batteries out. This guide explains the main types and where each belongs.

Smoke alarms

Smoke alarms react to smoke particles, which makes them the best early warning for fires that smoulder before they flame, such as a sofa or a bed. The two common types are:

• Optical smoke alarms, which are good at detecting slow, smoky fires and give fewer false alarms near kitchens. They suit hallways, landings and living rooms.
• Ionisation smoke alarms, an older type that reacts quickly to fast flaming fires but is more prone to false alarms from cooking.

Heat alarms

Heat alarms do not detect smoke at all. They go off when the temperature rises quickly or reaches a set level. That makes them right for kitchens, where steam and cooking fumes would set off a smoke alarm, and for garages and some loft spaces. They should not be the only alarm protecting an escape route.

Carbon monoxide alarms

A carbon monoxide alarm is different again. It detects the poisonous gas given off by faulty boilers, fires and stoves, and goes in the room with the appliance. Landlords in England must fit one in any room used as living accommodation with a fixed combustion appliance, other than a gas cooker.

Where each one goes

• Hallways and landings: smoke alarm, one on every storey as a minimum.
• Living room: smoke alarm, especially in larger homes and HMOs.
• Kitchen: heat alarm.
• Bedrooms: smoke alarms are often recommended, particularly in HMOs or where people smoke or use heaters.
• Rooms with a boiler or wood burner: carbon monoxide alarm.

Mains, battery and interlinked

Mains powered alarms with a battery backup are more reliable than battery only units, and interlinked alarms all sound together when one detects a fire, so people upstairs hear an alarm in the kitchen. Many HMO licences and new builds expect a mains powered interlinked system. Our safety checklist for London rentals covers the certificates landlords need.

Fitting and testing

Energy North Ltd fits and tests smoke, heat and carbon monoxide alarms and carries out EICR inspections across North, East and West London. Our City & Guilds certified electricians can usually attend within 48 hours, and certificates are emailed the same day. Thinking about a car charger too? See our EV charger installation page.