How Long Does a Boiler Service Take?

A standard annual boiler service usually takes between 30 and 60 minutes, and a typical combi boiler with good access tends to sit towards the shorter end of that. Older boilers, boilers in tight lofts or cupboards, regular boilers with a hot water cylinder, and visits that combine the service with a landlord gas safety check all take longer. If the engineer is in and out in a few minutes, the full checklist has not been done.

What Fills the Time

A service is not a glance at the pressure gauge. The time goes on a fixed sequence of checks, and each one needs the boiler in a particular state, which is why it can't be rushed without skipping steps.

• A chat and a look first. The engineer asks how the boiler has behaved over the past year and checks the outside of the appliance, the pipework and the surrounding area for leaks, corrosion or signs of overheating.
• Casing off, internals inspected. The burner, heat exchanger, electrodes and seals are examined and cleaned where needed. This is usually the longest part of the visit, especially on a boiler that has missed a year or two.
• Combustion analysis. A flue gas analyser measures what is coming out of the flue to confirm the boiler is burning gas safely and efficiently.
• Flue and ventilation. The flue is checked along its route, inside and out, for secure joints, damage and obstructions.
• Safety devices and controls. The components that shut the boiler down when something goes wrong are tested, and the boiler is run through a full cycle.
• Paperwork. You get a written record of what was checked and anything that needs attention.

For a fuller walk-through of each stage, see what happens during a boiler service, step by step.

What Makes a Service Take Longer

Boiler type

A combi heats water on demand from the mains and has everything in one box. A system or regular boiler works with a separate hot water cylinder, and a regular boiler also has tanks in the loft, so there is more of the system to look at. Our guide to servicing differences between combi, system and regular boilers covers this in more detail.

Age and condition

An older boiler, or one that has gone a few years without a service, tends to need more cleaning inside. Seals and gaskets on older models also need more care when the casing comes off and goes back on.

Access

A boiler in a kitchen cupboard is quick to reach. One in a loft with a narrow hatch, a cramped airing cupboard or behind stored belongings takes longer before the service has even started. Clearing the space before the engineer arrives is the simplest way to save time.

Combining it with a gas safety check

Landlords often book the annual service and the Landlord Gas Safety Certificate (CP12) together. That is sensible, but the certificate covers every gas appliance in the property, not just the boiler, so a hob, gas fire or water heater each adds to the visit.

Something needs fixing

If the engineer finds a worn part, the service itself still finishes, but the repair may need a second visit once the right part is ordered. Nothing extra should be done without you agreeing to it first.

How to Prepare So the Visit Runs Smoothly

• Clear a path to the boiler and space around it, including the loft hatch if that is where it lives.
• Find the previous service record if you have one. It shows the engineer what was flagged last time.
• Make a note of anything odd you have noticed: noises, pressure dropping, radiators slow to warm, hot water running cold.
• Tell the engineer where the gas meter is and make sure it is reachable.
• Expect the heating and hot water to be off for part of the visit, so avoid booking the slot you usually need a shower in.

Do You Need to Be at Home?

An adult needs to be there to let the engineer in and to hear what was found. For landlords, the tenant can provide access, but it helps to agree a time with them well in advance and to tell the company who will be there. The written record should come to you either way.

A Service That Is Too Quick Is a Warning Sign

A visit that takes ten or fifteen minutes cannot include the casing coming off, a clean, a combustion reading, a flue check and a test of the safety devices. If yours was that short, check the paperwork. It should list what was tested and, for the combustion analysis, show the readings taken. Our article on signs your boiler service was done properly explains what to look for.

This matters for more than peace of mind. Most manufacturers require an unbroken record of annual servicing to keep the warranty valid, and a record that does not show a proper service may not be much help if you ever need to claim. See how annual servicing protects your boiler warranty.

Booking Your Service

If your boiler is due, our annual boiler service in London is carried out by Gas Safe registered engineers following the full checklist, with a written record at the end. Tell us the make, model and where the boiler sits in the property when you get in touch, and we can give you a realistic idea of how long your visit will take before we book it.