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Boiler maintenance checklist

HomeServe engineer fixing a boiler - boiler maintenance

Have you checked your boiler lately? A boiler emergency is unfortunately a regular occurrence in winter. The last thing you want as a homeowner or landlord is a broken boiler that leaves you or your tenants without hot water or heating, but there are regular checks you can make all year round to reduce the chances of it breaking down.

This article is a simple checklist of seven boiler maintenance tips so that you can keep it in good health for longer and help avoid having to shell out for a replacement, which could set you back upwards of £1,500.

Customers also often ask us how often to service a boiler and how much a boiler service costs, so we’ll answer all these questions and make sure that you’re all set for another year of smooth running central heating and a cosily warm home.

To protect yourself and your home against boiler problems in future, HomeServe offers boiler and heating breakdown cover you can rely on.

Table of contents

  1. Boiler maintenance
  2. Need a new boiler?
  3. FAQs

Boiler maintenance

As the seasons change, so does the need for how we operate and use our boilers. Before we get to the business end where our boilers work extremely hard over winter, it’s always best to carry out boiler maintenance checks to make sure everything is in working order. If you’d like to further your knowledge on boilers, read our article on how boilers work.

1. Is your boiler pressure low?

Check once a month
One of the most common issues that crop up with boilers is low boiler pressure, which can stop your boiler from heating up properly (or at all) and make you think your boiler is broken. In actual fact, the remedy is usually a very simple tweak you can make yourself using your internal or external filling loop. Whether your gauge is manual or digital, the pressure should always be between 1 and 1.5 bars.

2. Have you bled your radiators?

Bleed them twice a year
This is a boiler maintenance tip that applies all year round, especially before you get to autumn and winter, when you’ll be cranking up the heat again for the first time in months. Bleeding a radiator is the process of releasing any trapped air from each radiator individually – it’s a natural part of having a gas central heating system as small amounts of air do get trapped in them over time. If your radiator has any cold spots at the top then it most probably needs to be bled.

Our guide to How to bleed a radiator will tell you all you need to know.

3. Is your boiler well ventilated?

Where your boiler is located within a compartment i.e. cupboard or if the boiler requires permanent purpose provided ventilation it is important to ensure that air vents are free from debris such as cobwebs etc and are not blocked. Compartments where boilers are located should not be used for storage of combustible materials and any ventilators into the compartment should be free from obstructions.

4. Have you checked the radiator valves?

Once a year before autumn/winter
It’s a very good idea to check your valves are open and working properly before winter comes. Our guide to changing radiator valves has detailed explanations of the different types of radiator valves available, including energy-efficient thermostatic radiator valves, along with diagrams of how they work. It also shows you some of the common problems that can happen with valves that could cause your radiator to not heat up at all. Try and check your valves once a year and you may be able to find and fix smaller faults without having to call someone out.

5. Is your condensate pipe in danger of freezing?

Every winter
Sometimes your boiler can stop working completely during a cold winter due to its condensate pipe freezing up. If this is a danger with your boiler, one energy-efficient way to avoid it, recommended by the Heating and Hot water Industry Council is to keep your heating constantly on low. While it’s likely to cost you slightly more, it could save you money (and a lot of hassle) in the long run.

If your condensate pipe does ever freeze up, there are a few things you can do at home to thaw it and avoid it happening again. Check out our guide to How to thaw a condensate pipe.

6. Check inhibitor levels within the heating system

Once every 12 months
Inhibitor within the system water is an essential ingredient to prevent corrosion taking place and the formation of magnetite, more commonly referred to as sludge. It is very easy for your professional engineer to check inhibitor levels at every annual boiler service. Maintaining a healthy level of inhibitor within the system should prevent costly breakdowns and remedial works such as system cleansers or power flushing.

Our article central heating inhibitor explained as it will tell you all you need to know.

7. Have you had your annual boiler service?

Once a year before winter
Get a Gas safe registered engineer to service your boiler once a year. A thorough check-over by an experienced professional will mean any small problems can be fixed before they turn into big, expensive ones. If you’re a landlord you must also get an annual gas safety certificate for your property, which is a separate check.

We recommend getting your annual boiler service done in September, so you can make sure it’s in good shape and ready for the winter ahead.

Need a new boiler?

We’re working with BOXT, who can install your new boiler as soon as the next day if you order before 4pm*. Get your fixed price now.


What maintenance does a boiler need?

There are a few simple checks you can do to keep your boiler running as it should:
1. Check the pressure is between 1 and 1.5.
2. Bleed your radiators twice a year.
3. If your boiler is kept in a storage cupboard, regularly check that nothing’s blocking its ventilation.
4. Check all the radiator valves are in good working order at least once a year before winter.
5. Check your boiler’s condensate pipe isn’t in danger of freezing when the temperature outside finally drops.
6. Check the level of inhibitor within the system every year
7. Do a central heating powerflush every 5 – 6 years.
8. Get your annual boiler service booked so a qualified professional can check things over and potentially stop any small problems becoming big ones.

What is done in a boiler service?

A typical boiler service checklist will include:

  • A visual inspection
  • Operation and control
  • Flue and combustion performance
  • Clean the main boiler components
  • Checks and test for safety when in continuous use
  • Conduct a record
  • Ensure the boiler is ready for use

Should you get your boiler serviced every year?

Yes. An annual service is part of healthy boiler maintenance and will help reduce the risk of a breakdown when you need it the most. A Gas Safe registered engineer will be able to detect small problems that you wouldn’t be able to – this will help to keep you safe and also help save you money in the long run. An annual service will also validate your boiler manufacturer’s warranty, if you have one.

*Subject to engineer availability.

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