A gas safety check confirms that a gas appliance can be used safely. A boiler service checks the condition of the appliance and keeps it running efficiently, in line with the manufacturer's instructions. The Health and Safety Executive (HSE), the regulator for gas safety, warns against assuming that an annual service covers the points of a safety check. It also warns against assuming that a safety check counts as effective maintenance. In England, landlords must arrange the safety check by law. The service is what most manufacturers require to keep a boiler guarantee valid.
Is a gas safety check the same as a boiler service?
No. The two jobs answer different questions. A safety check asks whether the appliance and its flue can be used safely right now. A service asks whether the appliance is in good condition and working as the manufacturer intended.
Manufacturers describe the split the same way. A safety check shows the appliance can be operated safely. A service keeps it running efficiently. A safety check on its own does not maintain reliability or performance.
The HSE is explicit on this point. Do not assume an annual service covers the items in a gas safety check. Do not assume a gas safety check counts as effective maintenance. Landlords in England need the check by law, and the guarantee usually depends on the service.
What does a gas safety check cover?
A gas safety check looks at whether each gas appliance and flue is safe to use. A gas appliance needs enough air for complete combustion. It also needs a flue, the duct that carries waste gases outside, that removes the products of combustion. Those products include carbon monoxide, a gas you cannot see or smell.
Only a Gas Safe registered engineer may carry out the check. The engineer carries an ID card showing which appliances they are qualified to work on. You can ask to see it before work starts.
The HSE also suggests asking for one extra test when you book. When arranging a safety check, you can ask the engineer to carry out a soundness test on the whole gas system, including the installation pipework.
What happens during a boiler service?
A service is hands-on work inside the appliance, so it is a job for a Gas Safe registered engineer. Nothing below is something you should attempt. Manufacturers describe a typical visit like this:
- The engineer shows their Gas Safe ID card and asks about any faults you have noticed.
- The casing is removed so components can be inspected and cleaned, including the heat exchanger, burner, ignition electrode, electrical connections, seals and controls.
- Water and gas connections and the flue are examined for wear.
- The system is checked for leaks, and heating and hot water controls are tested.
- A flue gas analyser may be used to check the combustion ratio.
- On a sealed system, the final pressure is checked against the manufacturer's figure.
- The visit is written up in the Benchmark service record at the back of the boiler manual.
The HSE advises that appliances and flues are maintained in line with the manufacturer's instructions. Where no instructions exist, annual maintenance is recommended unless a Gas Safe registered engineer advises otherwise. Effective maintenance is an ongoing programme of inspections plus any repairs the appliance needs.
Your boiler guarantee depends on the service, not the safety check
A gas safety check will not keep a manufacturer's guarantee alive. Guarantee terms are tied to servicing. Baxi links its warranty to registration within 30 days of installation, a completed Benchmark commissioning checklist and an annual service. Vaillant requires an annual service by a Gas Safe registered engineer, carried out to the manufacturer's instructions and recorded in the Benchmark logbook.
Miss that condition and the guarantee can fall away. Keep the Benchmark record with the boiler manual, because it stays with the property. Ideal Heating publishes its own warranty and certification terms in the same spirit.
On timing, Worcester Bosch advises a service every 12 months. For a new boiler, Ideal Heating notes that the first service normally falls a year after installation, then yearly from there. You can book both jobs through our boiler service and repairs page.
What the law requires from landlords in England
Landlord duties sit in regulation 36 of the Gas Safety (Installation and Use) Regulations 1998, as amended by the 2018 Amendment Regulations. The scope here is England. A landlord, for these purposes, is anyone letting property under a lease shorter than seven years or under a licence. That covers private landlords, councils, housing associations, hostels, B&Bs and let holiday accommodation.
- A safety check must be carried out every 12 months on each gas appliance and flue.
- The check must be done by a person recognised by the HSE, meaning a Gas Safe registered engineer.
- You may carry out the check in the two months before the due date and keep the existing expiry date.
- Existing tenants get a copy of the record within 28 days of the check.
- New tenants get a copy before they move in.
- You keep the records for at least two years.
The record itself has a set content. It names and locates each appliance and flue checked, gives the engineer's name, registration number and signature, the date, the property address, and the results, including any defects found and what was done about them. The record is issued once the check is complete, even where defects were found. It is not held back until repairs are finished.
Our guide to landlord gas safety in England sets out the duties in more detail. If you let rooms in a shared house, read gas safety in an HMO as well.
Do homeowners need a gas safety check?
There is no legal duty on an owner-occupier to have a gas safety check. The HSE still strongly recommends having gas appliances and flues checked at least every 12 months. It also advises regular servicing by a Gas Safe registered engineer to guard against carbon monoxide poisoning.
The risk is not theoretical. Around seven people a year die in Great Britain from carbon monoxide poisoning caused by gas appliances. It is illegal to use a gas appliance you suspect is unsafe. Turn it off, leave it off, and have a Gas Safe registered engineer examine it.
If you smell gas or suspect a leak, the National Gas Emergency freephone number is 0800 111 999.
Can both be done in one visit?
Yes. Manufacturers confirm that a safety check and a service can be carried out in a single appointment. For a landlord, that means one engineer, one visit, one set of paperwork: the safety record for the law, the Benchmark entry for the guarantee.
FM Power is Gas Safe registered and works across London and the surrounding counties, seven days a week, including evenings and weekends. Before any installation work you get a free home survey and a written fixed price. If you let property and the annual check is coming round, you can arrange a landlord gas safety certificate (CP12) and add a service to the same visit.
Sources
- HSE — Maintenance: gas appliances and flues
- HSE — Gas safety: home owners
- HSE — Gas safety check records and what to keep
- HSE — Gas safety checks: what needs them?
- HSE — Gas safety: landlords and letting agents
- HSE — Who is a landlord?
- legislation.gov.uk — GSIUR 1998, regulation 36
- legislation.gov.uk — GSIUR (Amendment) Regulations 2018
- Viessmann — Differences between boiler service and gas safety check
- Baxi — Boiler warranty information
- Vaillant — Domestic boiler guarantee terms and conditions
- Ideal Heating — Warranties and certification FAQs
- Worcester Bosch — How often should a boiler be serviced?
- Glow-worm — What does a boiler service include?
- Baxi — What happens at a boiler service