For landlords

What's checked in a landlord gas safety inspection?

In a landlord gas safety inspection, a Gas Safe registered engineer checks every gas appliance, fitting and flue the landlord is responsible for. Typical checks cover gas tightness, burner pressure or heat input against the data plate, the flue clearing safely, ventilation, and that safety devices work. Each appliance is recorded as pass or fail.

Reviewed by Jordan Valentine-Dunn, Gas Safe registered engineer · Portsmouth Gas Heating · Last reviewed July 2026

A landlord gas safety inspection is a safety check of the gas the landlord is responsible for, carried out by a Gas Safe registered engineer. The engineer works through every gas appliance, fitting and flue, and it usually takes around 20 to 30 minutes per appliance, so the total time depends on how many appliances the property has.

What the engineer checks

Gas tightness (soundness) of the installation, that there are no leaks.
Burner pressure or heat input, measured against the appliance data plate.
That the flue is clearing the products of combustion, using flue flow and spillage tests.
That there is adequate ventilation for the appliance to burn safely.
That the appliance's safety devices operate correctly.
That the appliance is stable, correctly fitted and not damaged.

The engineer records the result for each appliance as a pass or a fail, and notes any defects found. Those results are what appears on the gas safety record (the CP12) that the landlord keeps and shares with the tenant.

Only a Gas Safe registered engineer can carry out this check and judge whether an appliance is safe. This guide explains what a typical inspection covers; it isn't a substitute for the engineer's on-site assessment.

Frequently asked

How long does a gas safety inspection take?

Usually around 20 to 30 minutes per appliance, so a flat with a single boiler is quick, while a property with a boiler, hob and gas fire takes longer. Access and the condition of the appliances can affect the time too.

What does the engineer test on the flue?

The engineer checks that the flue is clearing the products of combustion safely, using flue flow and spillage tests. A flue that isn't removing combustion gases properly is a serious safety concern.

What happens if an appliance fails the check?

It's recorded as a fail and the defect is noted on the record. The engineer will explain the problem, and any remedial gas work must be carried out by a Gas Safe registered engineer.

Sources

Last reviewed July 2026. This guide is general information, not legal or safety advice, gas safety work must be carried out by an appropriately Gas Safe registered engineer. Rules can change, so check the linked official sources for the current position.

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