Save money with these summer boiler jobs

Paying your boiler a bit of attention in its off-season can save you money and set you up for a much easier time when autumn comes back around and bills start to creep up.

Summer is a good circuit-breaker for our central heating. But don't forget about it completely – it's an opportunity to deal with wear and tear from past year. And if you find a fault, a repair isn't as urgent. A boiler repair during the winter is a nightmare; in the summer it's a dodged bullet.   

Read our checklist of boiler jobs to think about now. And if you're looking for a Gas Safe-register engineer, find a Which? Trusted Trader you can rely on. 

If heating is a million miles away from your mind, read our electric fan buying advice to help you cool down.

1. Turn your boiler to summer mode

Many combi boilers have 'summer' and 'winter' modes that you can access within the menu on the control panel.

It's worth toggling summer mode on right now if your combi has it and you haven't already. This guarantees your combi boiler will only supply hot water and no central heating.  

If your boiler doesn't have summer/winter modes, don't fret. You can set the same thing up yourself by turning off your heating thermostat or adjusting its schedule so that it's set to only come on if temperatures drop below freezing. You may find your thermostat also has an equivalent 'hot water-only' mode.

If you don't need your boiler to produce any hot water – for example if you have an electric shower and a dishwasher – or a seperate water heater, then you can turn your boiler off. And if you have an old boiler with a pilot light, then it may be wise to turn that off too. 

Remember that while your heating is off over summer, it's a good idea to check that it's still working once or twice. Toggle the heating on briefly and make sure the radiators start to warm up. This is especially key if you don't have a boiler service.

Even if you're not using gas at all over the summer months, your energy company will still charge your daily standing fees for your gas supply. If you pay as you go, you'll still need to keep your meter topped up to cover those costs.

If you want to turn your boiler off completely and rely on an electrical water heater for the summer, read our explainer on immersion heaters to find out more.

2. Book a boiler service

A regularly serviced boiler will last longer, run more cheaply and is less likely to conk out in the middle of winter. 

One service a year is advised (and mandatory to maintain manufacturer warranties). Even if you don't regularly service your boiler, it's worth booking one in over the summer to make sure it's running efficiently, as gas prices are likely to still be high this autumn and winter – a more efficient boiler will be cheaper to run. You'll also lower the risk of an emergency repair.  

Summer is the best time to get your boiler serviced for a few reasons:

• You may get off-peak rates and a greater choice of engineers who aren't as busy with boiler repairs this time of the year. 
• If your boiler does need any repairs, it's less of an inconvenience during the hot summer months.
• You can deal with the wear and tear of the last heating season, and guarantee peak performance ahead of the next one.
• If your boiler is getting old, you can consider your next move (whether it be another boiler or a low-carbon option, such as a heat pump) without having your hand forced by an emergency decision.

Your boiler must be serviced by a Gas Safe-registered engineer and a service should last at least 30 minutes.

Find out how to get the best from your boiler service in our guide. 

3. Flush your central heating system

Heating systems need a power flush a couple of times every decade. It's a useful way to improve efficiency and prolong the life of your boiler.

A power flush works by cleaning the boiler, pipes and radiators with a chemical mix pushed forcefully through the system. As it happens, debris, rust and scale is cleared away, which lets hot water flow more freely through the loop.  

It might be worth asking your boiler engineer about doing a power flush if you noticed any of the following over winter:

• Radiators have cold spots that aren't fixed by bleeding them.
• The boiler responds more slowly than usual, even if you haven't changed its flow temperature.
• Heating sounds noisier than it used to be.
• You've drained or bled a radiator and the water that came out was very discoloured. 

You can bleed your radiators yourself to free trapped air if they are cold at the top and make gurgling sounds when your heating comes on.

4. Fix the roof while the sun is shining

This is metaphorically speaking, of course, although you may want to consider roof insulation. 

More broadly, if you have gaps, cracks and draughts in your home, it's good to insulate them over summer, while it's an easier and less urgent job.

In fact, insulation is a two-way street. Not only does it stop your home getting cold in the winter, but when done correctly it also prevents excess heat during the peak of the summer. 

In hot weather, it's good to ventilate your house when it's cooler, such as overnight, but lock out hot air during the heat of the day. 

Here's more on how insulation helps keep you cool over summer as well as the reverse.

If you're interested in larger insulation jobs, consider:

• Loft and roof insulation. Heat rises, so trapping it in from above is crucial. 
• Floor insulation can reportedly reduce heat loss by 15%. 
• Cavity wall insulation is useful for properties built in the last century. It's injected into the gap between your outer and inner walls. 
• Solid wall insulation can be placed in or outside a wall without a cavity. It's expensive to install, so it's a longer-term investment.  

Our insulation advice guides show you options, costs and where to start, from little jobs such as installing sealants and draught excluders to commissioning major retrofits

5. Consider new boiler controls

Some people have heating controls that are too basic to run the system at its most efficient. This is especially likely if your boiler was installed before 2018.

2018's Boiler Plus rules encourage the use of smart thermostats with new boiler installations. These automate some of your heating and help reduce costs by making it easier to use your controls with flexibility.

The two best types of boiler control are known as load compensation and weather compensation, which change how much heat your boiler produces depending on the heat demand of your property. While many smart thermostats can enable one of these controls, they don't always – and you need an engineer to set them up. 

A boiler service is a good time to bring this up with an engineer. Different boilers are compatible with different systems, so you'll need a thermostat-boiler combo that gets the most out of your model.

In some cases, an engineer will recommend traditional on/off controls along other measures, such as making use of thermostatic radiator valves. While these won't stop your boiler heating water up, they will stop your radiators getting hot in certain rooms. Your engineer will need to consider all the parts of your heating system to recommend the best combination of efficiency and thermal comfort.

Find out more about making your heating system work well in our guide to heating controls

6. Use our home energy planning tool 

If you're thinking about switching away from a gas boiler to a heat pump or another alternative, or if you're just interested in making your home more energy efficient, it can be tricky to know what types of installation would benefit your home's specific requirements. 

Our home energy planning tool aims to cut through the confusion, giving you information tailored to your property. Using data you input, as well as your EPC reports and other specifics, the tool will let you know how you can reduce your energy bills and how much it might cost upfront. 

You can get started with a plan and make any initial updates when your boiler is still working, so that you know you're well set up and ready to act when you do need a replacement.

Find out more and try out our home energy planning tool to start your personalised plan.

Looking for quick energy-saving tips? Head to our guide to the 10 best ways to save on your energy bill