CP12 vs Boiler Service: What Landlords Actually Need

For landlords, a CP12 gas safety check and a boiler service often sound like two names for the same task, but they are actually distinct services with different goals, processes, and documentation. Understanding the difference is crucial to meeting your legal responsibilities, ensuring tenant safety, and avoiding costly misunderstandings.

The CP12 focuses primarily on safety compliance and legal requirements, while a boiler service aims to maintain performance, extend the lifespan of your boiler, and prevent breakdowns. Knowing which one you need—and when—helps you stay organised, keep your tenants safe, and protect your investment without paying for unnecessary work.

CP12 and boiler service at a glance

A CP12, formally known as a Landlord Gas Safety Record, is a gas safety inspection for relevant gas appliances and flues provided for tenants. It must generally be completed by a Gas Safe registered engineer at least every 12 months, with records retained and made available as required. Always confirm the current requirements for your property and circumstances.

A boiler service is a more detailed maintenance procedure focused on the boiler itself. It aims to assess condition, clean relevant components, check combustion and support reliable operation, usually in line with the manufacturer’s instructions. A service is not automatically a substitute for a CP12.

• CP12: focuses on gas safety and produces the required safety record.

• Boiler service: focuses on maintenance, performance and identifying developing faults.

• Both together: can provide clearer records, improved reliability and broader reassurance.

What a CP12 gas safety check covers

During a CP12 inspection, the engineer checks the gas appliances and flues covered by the landlord’s responsibility. This can include the boiler, gas fire, cooker or other fixed appliances supplied with the rental property, along with accessible gas installation pipework and ventilation where relevant.

The engineer carries out safety checks such as looking for signs of damage, testing for gas tightness, checking the flue and ventilation arrangements, and assessing whether appliances are operating safely. The result is recorded on the Landlord Gas Safety Record, including details of appliances inspected, any defects identified and the engineer’s Gas Safe registration information.

A CP12 check is not normally a full clean or a comprehensive repair service. Components may be removed or adjusted where needed for safety testing, but landlords should not assume that the boiler will receive the cleaning and performance work included in a standard boiler service.

What happens during a boiler service?

A boiler service examines the boiler in greater depth than a basic safety check. Depending on the boiler type and manufacturer’s instructions, the engineer may inspect and clean the burner, heat exchanger, condensate trap and other accessible components, while checking seals, controls, flue condition and combustion readings.

The engineer should explain any maintenance needs or faults found and provide service documentation. Keeping this paperwork can help demonstrate a sensible maintenance history, support warranty or manufacturer requirements and highlight recurring problems before they become costly breakdowns.

A boiler service usually relates to the boiler only. It does not automatically include the gas cooker, fire or other appliances, and it does not necessarily create a CP12 record. If several appliances are supplied in the property, ask the engineer to confirm which appliances are included in each appointment.

Do landlords need both checks?

If you rent out a property with landlord-provided gas appliances, the CP12 is the key safety record to arrange within the required timeframe. A boiler service may not be a universal legal requirement in every situation, but it is commonly recommended to maintain the appliance, protect reliability and meet warranty or servicing conditions.

Many landlords choose to book both at the same time. This can reduce disruption for tenants and allows the engineer to complete the formal gas safety inspection while carrying out more detailed boiler maintenance. It also creates separate documentation showing both compliance activity and ongoing care.

A simple decision guide

• If you rent out a property with gas appliances: arrange a CP12 gas safety check at least every 12 months, subject to the requirements that apply to you.

• If you want better boiler reliability or warranty support: arrange a boiler service as recommended by the manufacturer or engineer.

• If your property has a cooker, fire or other gas appliance: confirm that it is included in the CP12 inspection and service scope.

• If an appliance is unsafe: follow the engineer’s advice immediately and do not allow it to be used until the issue has been addressed.

Common questions from landlords

Does a CP12 include cleaning?

Usually, no. The CP12 is primarily a safety inspection and record, rather than a cleaning or preventative maintenance service. Minor adjustments may be made where necessary for safety, but detailed cleaning should be agreed as part of a boiler service.

Does a boiler service check other gas appliances?

Not unless this has been specifically included in the booking. A boiler service is generally limited to the boiler, whereas a CP12 should cover the relevant landlord-provided gas appliances and flues listed on the record.

What about gas cookers and fires?

Gas cookers, fires and other fixed appliances supplied to tenants may need to be included in the landlord’s gas safety arrangements. Tell the engineer about every appliance at the property and keep the completed record with your other landlord documents.

What if an appliance is unsafe?

The engineer will explain the defect and advise whether the appliance should be repaired, disconnected or taken out of use. Follow that advice promptly, keep a record of the action taken and only return the appliance to service once it has been confirmed safe.