What does a boiler service include? A Gas Safe engineer's checklist

A boiler service is a set list of checks on safety, efficiency and reliability, carried out by a Gas Safe engineer. Here is exactly what to expect when you book one.

Visual inspection

• ◆Check the boiler casing for damage, corrosion or signs of leakage
• ◆Inspect the flue terminal externally to confirm it is clear, correctly positioned and unobstructed
• ◆Check ventilation requirements for the boiler cupboard or room are met
• ◆Look for evidence of water or gas leaks around pipework connections

Combustion and gas safety checks

• ◆Measure flue gas readings with an analyser to confirm the burner is burning cleanly and efficiently
• ◆Check gas pressure at the inlet and the burner to confirm they are within manufacturer tolerance
• ◆A gas tightness test of the installation pipework
• ◆Test all safety devices: overheat thermostat, pressure relief valve and gas valve response

Heat exchanger and components

• ◆Inspect and clean the heat exchanger if accessible
• ◆Check the burner head for signs of deterioration or incomplete combustion
• ◆Inspect the condensate trap and drain for blockages - a common cause of winter lockouts
• ◆Check the magnetic filter for sludge accumulation and clean it if present

Controls and function test

• ◆Verify the programmer or smart thermostat is operating correctly
• ◆Test the boiler through a full firing cycle - ignition, run, modulation and shutdown
• ◆Check system pressure and top up if required
• ◆Sign and log the service record

What you receive at the end

After the service, you should receive a signed service record. This is the proof your warranty provider will ask for if you ever make a parts claim. We send a digital copy by email so it is always accessible.

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