How Much Does a Gas Safety Certificate Cost?

Who actually needs a gas safety certificate

Only landlords are legally required to hold one. gov.uk's private renting guidance is explicit: a landlord must have a Gas Safe registered engineer do an annual gas safety check on each appliance and flue, and give the tenant a copy before they move in or within 28 days of the check. An owner-occupier has no such duty, and a mortgage lender will not ask for a certificate on a purchase.

That changes the question for a buyer. If you are buying to let, the CP12 is a fixed running cost you will pay every year from day one. If you are buying to live in, the certificate is optional, but the underlying check, is the boiler safe and the flue sound, is still worth £60 to £90 on an older installation.

What the check covers

• Every gas appliance the landlord supplies: boiler, hob, oven, gas fire, water heater.
• Flues and chimneys, for correct operation and no spillage of combustion products.
• Pipework, for tightness (a leak test) and adequate ventilation.
• Safety devices and the operating pressure and heat input of each appliance.
• It is not a boiler service. A service is a separate maintenance job, though many engineers offer both in one visit for a bundled price.

What buyers should ask for

If the seller is a landlord, ask for the current CP12 and the last two years' records. Gaps or repeated "at risk" or "immediately dangerous" classifications on old records tell you how the installation has been looked after. If the seller is an owner-occupier, ask for the boiler service history instead; there will be no certificate to show.

A boiler that fails a safety check is a negotiating item, not necessarily a deal-breaker. A replacement boiler costs far more than the £60 to £90 check, so the check is cheap insurance on any property where the boiler is more than ten years old. The same logic applies to the EICR for the electrics.

How to save

• Bundle the check with a boiler service. Both sources note engineers price the pair lower than two separate visits.
• Count appliances before you book, so the quote covers everything and there is no per-appliance surprise on the day.
• Landlords with more than one property should ask for a block-booking rate.
• Use the Gas Safe Register to verify the engineer's ID card. Logbook's guide points out that a certificate from an unregistered engineer is worthless, and for a landlord it can invalidate a Section 21 notice.
• Outside London, expect the lower end of the range; Logbook puts the London and South East premium at 15 to 30%.