Heat detectors perform best when they're positioned to detect rising temperatures quickly and without obstruction. Getting the placement right means understanding how heat moves in a room, which areas benefit most from heat detection, and where the boundaries of a heat detector's appropriate use lie.

How Heat Moves in a Room

Hot air rises. In a fire, the heat generated at the source rises rapidly and spreads along the ceiling before descending as the fire grows. This means the ceiling — particularly the central area of the ceiling — is the optimal location for a heat detector. Heat reaches a ceiling-mounted detector before it would reach a wall-mounted or lower unit.

Corners and the junction between ceiling and wall create dead air pockets where air movement is reduced. Avoid placing detectors within 300mm of a wall or within 600mm of a ceiling corner.

Recommended Locations for Heat Detectors

The primary applications for wireless heat detectors are environments where smoke alarms would generate unacceptable nuisance activations. These include:

Kitchens — the most common location. Cooking produces steam, oil vapour, and combustion particles that trigger smoke alarms. A heat detector provides fire coverage here without false activations.

Garages — vehicle exhaust, paint fumes, solvents, and petrol vapour create an unsuitable environment for smoke detection. Heat detectors cover this space reliably.

Boiler rooms and utility spaces — hot water cylinders, gas heaters, and similar equipment can generate low-level fumes or dust that cause nuisance alarms in smoke detectors.

Laundries — particularly where tumble dryers are in use, lint and steam can trigger smoke alarms. A heat detector is more appropriate.

Positioning in the Kitchen

In the kitchen specifically, positioning relative to the cooking appliances matters. Placing a heat detector directly above a hob or oven means it will be exposed to concentrated heat during normal cooking. Over time, this can cause thermal stress to the unit, and it also means the detector may trigger during high-temperature cooking.

The recommended position is between the cooking area and the main exit of the kitchen — towards the ceiling centre, but offset from directly above the hob. Most manufacturers specify a minimum distance from cooking appliances; one metre is a common guideline.

Multi-Room Properties

In larger homes where the kitchen is separated from the main living areas, a single heat detector in the kitchen should still be wirelessly interconnected with all smoke alarms in the home. The interconnection ensures that a heat alarm activation in the kitchen triggers the full alarm network.

In open-plan kitchen and living areas, the placement decision requires more care. If smoke detection covers the living area portion, and heat detection covers the cooking zone, ensure the two zones overlap sufficiently to avoid a gap where neither type detects effectively.

What to Avoid

Do not install heat detectors in bedrooms, hallways, or stairwells. In these locations, early detection of slow smouldering fires is critical — and heat alarms are inherently slower to respond than smoke alarms. A smoke alarm that activates four minutes earlier than a heat alarm in a sleeping area is not a minor difference.

Also avoid placing heat detectors near air vents, extractor fans, or open windows. Airflow that continuously moves warm air away from the unit will slow its response to rising temperature.

Ceiling vs Wall Mounting

Ceiling mounting is always preferred for heat detectors. If ceiling mounting is not possible, wall mounting between 150mm and 300mm from the ceiling is acceptable for most units — check manufacturer specifications. Below 300mm from the ceiling, detection will be slower as heat must build to a greater depth before the detector registers it.