Gas

The gas diagnostic, essential prevention

This diagnostic covers the condition of a home’s internal gas installation when it is more than fifteen years old. It aims to spot faults that could lead to a leak, carbon monoxide poisoning or an explosion. By checking the equipment and connections, it helps make everyday use of gas safer.

Why it should not be overlooked

Gas remains a reliable energy source, but an old or poorly maintained installation can become dangerous. Carbon monoxide, invisible and odourless, is particularly fearsome. This diagnostic gives clear visibility over the installation’s sensitive points and over the safety precautions to adopt.

Scope and obligations

The gas diagnostic is mandatory for the sale as well as the rental of a home fitted with an installation more than fifteen years old. It joins the file given to the buyer or tenant, who must have reliable information about the safety of the installation before committing.

What the assessor checks

The intervention covers the key components of the installation, from the gas supply through to the appliances:

• The condition of the fixed pipework and its connections
• The connection of cooking, heating and hot-water appliances
• The ventilation of the premises and the airflow needed for proper combustion
• The combustion of appliances and the evacuation of combustion products
• The presence of accessible shut-off devices

How the check proceeds

The assessor visually inspects the installation and checks that the appliances connected to the gas work correctly. They need access to the kitchen, the heating appliances, the boiler and the ventilation devices. The intervention, generally around an hour, depends on the number of appliances and the layout of the premises.

What the report contains

The report details the anomalies found and ranks them by degree of severity. In the event of a serious and immediate danger, the assessor may have to report the need to interrupt the supply to the appliance or installation concerned, in order to remove any risk to the occupants.

How long is it valid?

The validity of the gas diagnostic is three years for a sale and six years for a rental. Beyond that, a new check must be carried out to attest to the condition of the installation for a new transaction or a fresh letting.

The consequences of a missing diagnostic

A missing or expired diagnostic can engage the seller’s or landlord’s liability, particularly if a gas-related accident occurs. Given the potential severity of incidents, from poisoning to explosion, holding an up-to-date assessment is an indispensable protection for all parties.

The factors that vary the price

The fee depends on the floor area, the number of gas appliances, the age of the installation and the location. As the electrical diagnostic is often paired with it, having both done during the same visit usually helps reduce the overall cost of the file.

Frequently asked questions

Does the gas diagnostic replace servicing my boiler?

No. Annual boiler servicing is a separate obligation, carried out by a heating engineer. The diagnostic records the general condition of the installation but does not replace this regulatory servicing.

What should I do if a serious and immediate danger is reported?

The appliance or installation involved must be taken out of service until it is repaired by a professional. The report is intended to protect the occupants without waiting for the sale or rental.

Is an all-electric home concerned?

No. With no internal gas installation, this diagnostic has no reason to be carried out. It applies only to homes actually fitted with a gas-fed installation.