Guide
How often should you service your boiler?
Short answer
Service a gas, LPG or oil boiler once a year. HSE says gas appliances should be serviced at least annually by a Gas Safe registered engineer. Most boiler warranties also need a yearly service. Landlords must have a gas safety check every year, which is a separate legal duty.
Why a yearly service matters
A yearly service keeps the boiler safe and efficient. A badly working boiler can make carbon monoxide, which has no smell.
A service can find small faults before they cause a breakdown in winter. Most boiler makers also need a yearly service to keep the warranty valid. Check your warranty terms.
What a gas boiler service covers
The engineer follows the maker's service instructions. Most services include the checks below.
- A visual check of the boiler, flue, pipework and controls.
- A check of the gas pressure and gas rate.
- A flue gas analysis, to check the boiler burns cleanly.
- A clean of the parts the maker lists, such as the burner and condensate trap.
- A check of the safety devices, seals and ventilation.
- A written service record.
What an oil boiler service covers
An oil service covers the same safety checks and more cleaning. The technician usually changes the burner nozzle and the oil filter, and cleans the combustion chamber.
They also check the oil line and the tank. Ask them to look for cracks, leaks and a missing bund. Use a technician who is competent in oil, such as one registered with OFTEC.
Service or safety check?
A gas safety check confirms an appliance is safe to use. A service also cleans and adjusts it to work well.
Landlords in Great Britain must have every gas appliance and flue they provide safety checked every year. The engineer gives a landlord gas safety record. Many landlords book a service and the safety check in one visit.
Warning signs between services
Call a Gas Safe engineer if you see any of these signs. Turn the appliance off until it is checked.
- A lazy yellow or orange flame, not a crisp blue one.
- Black or brown marks on or around the boiler.
- More condensation than usual in the room.
- The pilot light often goes out.
- Your carbon monoxide alarm sounds. Open windows, go outside and call 0800 111 999.
What it costs
Most local firms charge a fixed price for a service. See our boiler service cost guide for prices that Cotswold firms publish, and national figures.
Questions
Is a yearly boiler service a legal requirement?
Not for owner-occupiers. HSE advises a service at least once a year. Landlords must have a yearly gas safety check by law.
When should I book a service?
Many people book in late summer or early autumn, before the heating goes on. Engineers are often busy in winter.
Do heat pumps need a service?
Most makers advise a yearly check by a competent installer. Read the warranty terms, because some need a yearly service to stay valid.