We use cookies to allow us and selected partners to improve your experience and our advertising. By continuing to browse you consent to our use of cookies. You can understand more and change your cookies preferences here.


26 May 2022

Do these 5 boiler jobs in summer to prepare for winter energy use

We've rounded up five key boiler tasks you need to do now to leave you in good stead for the winter 
Engineer working on a boiler in a home

Summer is just around the corner, but that doesn't mean you should forget all about your boiler. It's the best time of the year to get it shipshape, so you won't get any nasty surprises when winter comes.

Unfortunately, the spiralling cost of energy means that next winter is set to be an expensive time when it comes to heating your home. 

It will be more important than ever to make sure your heating is as efficient as possible when the thermometer drops.

From quick jobs to large-scale projects, here's our checklist of boiler jobs you should consider doing over the spring and summer.

Every year, we ask consumers about boilers they own and we ask engineers about boilers they service to find the most reliable brands. Read our 2021 boiler reviews to find a Best Buy based on the highest brand scores.

1. Arrange an annual service with a Gas Safe engineer

Spring and summer are the best times to get your boiler serviced. This is because demand is lower and the detriment of an out-of-service boiler awaiting repairs won't leave you in the cold.

You should get your boiler serviced at least once a year. If you have a boiler cover insurance policy or boiler warranty, they'll likely require an annual service in the terms.

A boiler service involve several jobs, including but not limited to:

  • Visual assessment of the boiler, flues, case seals and other essential components
  • Checking of the pressure gauge and/or heat input
  • Removal of the casing so that internal components can be assessed
  • The boiler will be operated to check for any faults in use
  • If needed, boiler parts will be cleaned
  • A service report will be produced by the engineer

Your engineer will need to be accredited by the Gas Safe Register. 

To find a tradesperson you can trust, we recommend finding a Which? Trusted Trader in your area.

2. Toggle the summer setting (if you have one)

Some modern combination boilers have a 'summer mode', which heats your water a few times a day while keeping fuel costs much lower than during the winter. 

This means that your sinks, showers and more can still be supplied with hot water, even if you're not using your central heating at all.

Popular boiler brands such as Worcester Bosch and Vaillant have added this setting to modern combi boilers, so it's worth taking a look.

If you're looking for it on a rotary dial or a digital screen, we've seen it symbolised as a parasol icon on boilers from these brands. 

Read our guide to boiler controls and thermostats to find out which settings to look out for to achieve the best efficiency.

3. Get acquainted with how your boiler actually works

Now is a great time to find your instruction manual, in print or online, and become familiar with your boiler. 

There are a lot of settings on your boiler you may not be aware of, many of which may be able to actually cut costs for you.

For example, you can turn down the flow temperature of your boiler (separate from the thermostat) to increase the efficiency of its heating. 

Reducing the flow temperature will make your radiators less hot to touch, and prolong the time it takes to heat up your home, but it will aid in a boiler successfully running its condensing mode and recovering heat. 

This helps a boiler to reach its maximum rated efficiency. 

For example, an A-rated boiler isn't always that energy-efficient, that's just how energy-efficient it can be under the right conditions. For many, reducing flow temperature is a way to realise this potential. 

Read more: our guide to boiler efficiency.

Admittedly, it's complicated, and finding flow temperature in the first place is a bit of a task because it is hidden beneath settings on the control panel. If you're having your boiler serviced anyway, your engineer may be able to help you get set up.

Getting it sorted in summer means you can go into the cold weather armed with a better knowledge of your boiler from the outset, and knowing it's operating as efficiently as possible.

Read our smart thermostats reviews to find out the best remote temperature control system you can operate with a smartphone or voice assistant. 

4. Schedule a practice run 

Turning on your boiler on the first chilly autumn day and having it seize up is highly inconvenient. 

Not only will it leave you cold, but you'll be under additional stress to fix or replace your boiler quickly.

It may be wise to schedule one or two dates during the summer to turn on your boiler to make sure it's working properly.

When you do this, it's also a good idea to check the pressure gauge is hovering over the green zone, as well as check the radiators to see if they need bleeding. 

If your radiators are cold on the top but warm on the bottom, or if they're emitting a strange noise, they may be in need of bleeding so that heat can distribute evenly throughout again. 

You may recoil at the thought of wasting energy during the summer – and if you've just had your boiler serviced then you can probably ignore this one. 

But even if you only do this once towards the end of the season, it'll give you peace you mind that your boiler and radiators are up to the job.

Find out how much a brand new boiler costs by reading our guide to boiler prices.

5. Size up possible insulation tasks

A well-insulated home will save you money in the long-run by increasing the efficiency of your home. 

Insulation tasks can involve whole-home renovations or small, quick fixes. 

If you're efficiency-minded, then no improvement is too small, and it can help to start with small jobs to avoid the whole thing being too daunting. 

And as the old adage goes: it's best to fix your roof while the sun is shining. 

Small fixes you can look out for are:

  • Sealing small cracks and openings in doors, windows, electricity fittings, loft hatches, floorboards and elsewhere.
  • Insulating the space behind radiators with foil to reduce heat loss through the wall behind the radiator. 
  • Setting down draught excluders beneath doors, on postboxes, on keyholes.
  • Buying thicker curtains to cover your windows when the weather turns, and if you have single-glazed windows, buy insulating film. 

If you have the time and the budget for greater tasks, like loft insulation or cavity wall insulation, that will help to lower your home energy consumption later this year. 

But you don't need big outlays to start making a dent in your bills.

Read our insulation guides to find out where to start with cheap fixes as well as extensive renovations – all of which will increase the energy efficiency of your home.