What does a boiler service include?

A boiler service follows the manufacturer’s instructions for the specific appliance. We inspect the installation, test combustion and safety controls, clean serviceable parts, and record anything that needs repair.

Your boiler may still provide heat while a fault develops. That is why we do more than check whether it fires. We look at how safely it burns gas, removes combustion gases and responds when its controls call for heat.

• Visual inspection: We check the boiler casing, pipework, flue, ventilation and surrounding area for damage, corrosion, leaks or signs of overheating. On older properties, we also look for installation issues that could affect safe operation.
• Flue and ventilation checks: The flue must carry combustion gases safely outside, while the appliance needs suitable air for combustion. We inspect accessible sections and check the flue termination and route for visible problems.
• Gas and combustion testing: We measure the boiler’s operating performance with calibrated equipment. This helps us identify unsafe combustion, incorrect gas pressure or a problem with the flue before it becomes more serious.
• Safety controls: We test the controls that should shut the boiler down if it detects an unsafe condition. We also check the thermostat and other operating controls so the appliance responds correctly.
• Internal inspection and cleaning: We remove the casing where the appliance design allows it and inspect components such as the burner, heat exchanger, electrodes and seals. We clean parts when the manufacturer’s instructions call for it, rather than removing components unnecessarily.
• Condensate system: On a condensing boiler, we check the condensate pipe and trap for blockages, leaks or poor installation. A frozen or blocked condensate route can stop the boiler from operating.
• Water and pressure checks: We check the heating system pressure and look for signs of leaks or poor circulation. A pressure problem may point to an issue elsewhere in the system, such as the expansion vessel or a radiator valve.
• Electrical and wiring checks: We inspect accessible electrical connections, controls and isolation arrangements for damage or unsafe conditions.

If we find a problem, we explain what it means before carrying out additional work. A service can identify a failing part, but replacing that part is a repair and should be agreed separately. We do not describe a boiler as safe to continue using if our tests show a risk.

Gas work must be carried out by a Gas Safe registered engineer. That registration matters because the checks involve the gas supply, combustion and products of combustion, not just the heating controls.

At the end, we explain the boiler’s condition and note any recommendations in the service record. Keeping that record helps you track recurring faults and gives the next engineer useful information about the appliance’s history.

A boiler service does not normally include balancing radiators, repairing leaks, replacing controls or checking every part of the wider heating system. We can identify where the wider system is affecting boiler performance, then tell you what further investigation would involve.

For a rented property, a routine service and a landlord’s gas safety record are related but different pieces of work. The gas safety check must cover the relevant gas appliances and installation, with the required record completed for the landlord and tenant.

Before we attend, make sure we can reach the boiler, controls and any accessible flue or condensate components. If the boiler is enclosed, the engineer may need the cupboard cleared so the casing and connections can be inspected properly.