From small jobs to big changes, here are our top tips for cutting your energy bills
WHICH? consumer research found that in August 2022, 65% of households cut back, dipped into savings or borrowed money in order to cover essential spending. And with most people’s gas boilers whirring into action this month as the temperature drops, outgoing expenses are only increasing.
Our experts have identified a variety of ways to reduce your heating energy bills this winter.
The big things can drastically change how much energy you use every year, while the small things can cheaply make an immediate dent in your bills during a time where a bit of help goes a long way.
Sometimes it’s simply a matter of using a new boiler setting or spending 15 minutes plugging a gap in your home that provided a welcome breeze during the summer heatwave. We’ve also listed a few more expensive, longer-term fixes. If you do feel able to, it’s worth thinking about whether any of these could suit your home.
Read on for our top tips for getting ahead this winter.
Emily Seymour, Which? Energy and Sustainability Editor, said: “Many people will be looking to save money by reducing their energy use this winter. Some easy ways to cut your bills include using radiator valves to make sure each room of your house is only ever as warm as you need it to be.
“If your home has a single room thermostat, it should be set at the lowest comfortable temperature as heating bills will rise by about 10 per cent for every additional degree you turn it up.
“Combi boiler owners can try turning its flow temperature down and the preheat setting off. Tap water will initially come out cool before it heats up, but you’ll be wasting less energy.
“If you have a hot water cylinder, you can’t make use of low flow temperatures. Instead, insulate your hot water tank with a jacket no less than 75mm thick and make sure you’ve got lagging on pipes.
“Simple steps like placing weatherproofing tape over gaps or putting down a draught excluder can guard against heat loss.”
Get our latest cost of living news and advice to support you through the colder months.
1. Check your boiler settings
Boilers are easy to cast as a cost-of-living villain. They’re big, sometimes noisy, most of them run on fossil fuels, and they can have a big impact on your energy bills – in fact, in most homes the boiler is the one single thing that uses up the biggest portion of your annual energy bill.
But a central heating system that’s working efficiently and using energy proportionate to your home’s heating need is still the best way to heat your home during the coldest months of the year.
For most people, the priority should be making your boiler cost less to use, and not deferring to replacements like portable heaters.
There’s a lot you can do to make your heating run more efficiently:
- Get your boiler serviced. This will reduce the chance of a costly emergency repair and keep a new boiler in warranty. Plus, a well-maintained central heating system will run more efficiently, and you can ask your boiler engineer about whether your boiler’s settings can be toggled to run more cheaply. If you rent, you are within your rights to ask your landlord to arrange a boiler service every year.
- Toggle pre-heat off. Combi boilers use water on demand, but sometimes they pre-heat water so it’s ready to get to taps quicker. This is nice, but it will keep your boiler burning more than it needs to.
- Bleed your radiators – or ask an engineer to do it if you prefer – and install thermostatic radiator valves (TRVs) onto them so you can turn radiators off in rooms you don’t often use (more on this below).
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2. Adjust your combi boiler’s flow temperature
Combi boiler owners should look at their flow temperature. You can save up to 8% on your heating bill by turning down the temperature of the water that gets circulated around your radiators. If your boiler heats this water to its max, your boiler won’t even condense, which means it’s running inefficiently.
Head to our full guide on how to adjust your boiler to lower your heating bill to find out more.
The Heating & Hot Water Industry Council (HHIC) recommends that people adapt their boiler settings with the advice of a boiler engineer. This is particularly true if you have a system or regular boiler that keeps water stored in a tank. Because stored water needs to be heated a certain amount to avoid Legionnella bacteria, you should only change settings with professional advice if you have one of these.
However, if you have a combi boiler, you’ve made sure it’s safe and you’ve checked your boiler’s technical manual, you can adjust these settings yourself.
This setting is accessible to anyone and it can be changed using your boiler controls. The flow temperature for heating is generally symbolised by a little picture of a radiator, and for hot water, a picture of a tap. Up and down arrows will change the temperature settings.
Nesta has created a free step-by-step boiler temperature tool to walk combi boiler owners through the process of changing flow temperature settings for your heating.
It recommends a 55°C setting, but we suggest starting a bit higher initially to see if you’re comfortable with the change.
3. Insulate your boiler’s hot water cylinder and pipes
if you have a boiler with a hot water tank, the advice above doesn’t apply. That’s because boilers that store water in a tank usually can’t manage the efficiency gains of combis as they’re not well suited to running low flow temperatures without modification.
You shouldn’t change the flow temperature of a regular or system boiler with a hot water cylinder without consulting an engineer, because your boiler must be able to pasteurise stored water effectively to avoid bacteria such as Legionella developing.
However, that doesn’t mean there’s nothing you can do to improve your boiler’s efficiency. You’ll be using a lot of energy to heat up the water in your storage cylinder, and you don’t want to lose out on any of that. So make sure the cylinder itself is well insulated. This can be as easy as buying a jacket for about £20. It should be no less than 75mm thick according to industry standards.
You can also lag the pipes that carry water around your home for around £5 a metre. Water loses a lot of heat in transit, so it’s a small expenditure for a good long-term saving. It’s particularly useful to do it for the pipes coming in and out of the cylinder.
Lagging pipes will also reduce the risk of them freezing in a cold spell, which can be costly to repair.
Find out what to do if external pipes freeze over with our guidance on how to thaw a frozen boiler condensate pipe.
4. Automate your heating with smart thermostats
Smart technology isn’t for everyone, but if you do like using your phone, tablet or voice assistant for managing your home, then a smart thermostat will give you easy and precise control over your central heating.
They’re designed to provide automation to help you use your heating at the best times. Whether it’s toggling your boiler when you’re nearby to benefit from it, learning your routine so it can predict the optimal times to run or even checking the weather forecast to anticipate increases and decreases in heating need, smart home heating is becoming increasingly clever.
While many of these features are designed for your comfort, rather than your wallet, smart thermostats really come into their own when it comes to making savings if you set up zonal heating with compatible radiator valves.This means you can vary the routine and temperature of different rooms so you’re not wasting energy by heating rooms at the wrong times.
For example, you might want to programme your kitchen to get a burst of heating in the morning before you put the kettle on and your living room to be warmest in the early evening, while you’re happy for your bedroom to stay cold all day until you’re about to go to bed. All of these adjustments mean you’re saving crucial kilowatts by never heating a room you’re not actually using.
Since the introduction of new legislation in 2018, new gas boilers need to come with one of four energy-saving add-ons. Smart heating controls are one of them. But if you have an older boiler you can still buy and install a smart thermostat separately.
Read our smart thermostat and smart radiator valve reviews to find models that will suit your needs.
5. Use thermostatic radiator valves
If smart tech isn’t for you, you can still make significant improvements by installing manually operated thermostatic radiator valves, or TRVs. They control the heat of your home by adjusting how much hot water flows through the radiator they’re fitted to, so you can make sure each room of your house is only ever as warm as you need it to be.
It works by sensing the room temperature and opening or closing the valve as appropriate.
The numbers on TRVs determine how much a radiator is allowed to heat up. They correspond more to a level of comfort than a specific temperature, but as a rough guide the following applies:
| 0 | Off |
| * (the maintenance setting) | The radiator will turn on as a protective measure when the temperature nears 0°C. |
| 1 | Approximately 12°C, a low room temperature for an unoccupied room |
| 2 | Approximately 16°C, a lukewarm heat for an occupied room. |
| 3 | Approximately 20°C, a comfortable heat for an occupied room. |
| 4 | Approximately 24°C, a warm heat for an occupied room. |
| 5 | The valve is fully open. |
Use trial and error. We recommend using settings two and three to try and cut heating use, knowing that you can go higher if you’re feeling chilly.
If you’ve also turned down your boiler’s central heating flow temperature, you might find you need to open your TRVs to higher settings to reach comfortable temperatures.
Smart radiator valves can work with smart thermostats to do this automatically. Some of them also take temperature readings to fine-tune your thermostatic system.
6. Turn your thermostat down a little
It’s age-old advice, and for people who are already frugal with their heating it may not apply. But each degree you turn your thermostat down is energy saved. According to the NHS, temperatures as low as 18°C are healthy for most people.
The Energy Saving Trust claims that turning your thermostat down by one degree can save you up to 10% off your heating bill. Realistically, a lot of variables affect this, but even one degree lower will move your bills in the right trajectory.
For older people, Age UK reminds that very low temperatures can increase your risk of flu or other breathing problems, and can raise your blood pressure. When you’re older, your blood pressure takes longer to return to normal once you get cold. Try to make sure you’re keeping at least one room at a comfortable temperature for you, and keep the doors closed as much as you can to keep that room as warm as possible.
7. Only use electric heaters sparingly
We’re often asked whether people should turn off their heating completely and replace it with electric heaters. Unfortunately, it’s unlikely to be cost effective over long periods of time.
Portable electric heaters use electricity to warm the air by convection, either with an exposed heating element, or with a radiator design that transfers heat from the element through a system of fins.
They are great at providing a quick heating fix for a short period of time, such as for a 10-minute blast on a particularly freezing morning. And if your central heating system isn’t working, they’re reliable back-ups.
It’ll take a portable heater between 15 – 30 minutes to raise the temperature of a medium-sized room by 10ºC at full blast. After that it will toggle on and off as needed to maintain temperature, based on its thermostat.
Remember that you pay for energy by the unit. With the current price cap, electricity is much more expensive than gas. So be prudent when you use your electric heater in place of gas.
They usually have rated outputs of 2 or 3kW – that’s how many they’d get through in an hour on full blast. For reference, that’s about the same amount of energy as a kettle. Heaters do generally have settings that let them run at lower outputs too.
If you’re on a standard variable tariff, the average unit price for dual fuel customers is 34p per/kWh for electricity and 10.3p per/kWh for gas. That means that a 2kW portable heater at its full output would use 34p of electricity every half an hour.
Read our electric heater reviews to find a model that provides good value.
8. Draught-proof for a quick, cheap fix
If you’re short on cash, there are things you can do right now to plug in gaps in your home and hold onto your heat.
You can draught proof any gaps in your home, whether that’s keyholes, postboxes, door cracks, cavities near doors and windows, or gaps around electrical outlets and pipes. Just remember that homes do need some ventilation, so make sure you leave any purpose-built vents clear, such as window trickle vents or grills in wodden flooring.
Draught-proofing may involve putting down tape or a draught excluder where there’s a draft. Even something basic like a door snake is a help in the war against heat loss. Many of these solutions cost less than a tenner, or can be homemade.
Other tools include:
- Adhesive weatherproof tape made of PVC or foam to go around doors and windows.
- Threshold seals to go on either side of doors.
- Letterbox excluders with brush pile material.
- Thermoplastic rubber (TPR) to fit flexibly into door and window cavities.
- Pillows designed to fit inside an open chimney to block off draughts when it’s not in use.
One visit to a DIY shop can provide you with several small solutions that don’t break the bank and can be installed yourself.
While individual draught-proofing measures are unlikely to save huge sums from your energy bills in isolation, collectively they will make your home feel more pleasant and cosy to be in. You might even find you can comfortably turn your thermostat down a degree.
Read our guidance on draught-proofing your home for more detail about small steps to seal your home.
9. Invest in insulation
In the long run, the key way to keep energy bills low is to trap as much as possible of the heat we generate inside our homes.
If you have the money to do it, insulation is a very good long-term investment. As energy bills go up, the time it takes to see a return on your investment becomes shorter. The Energy Saving Trust estimates that having a professional install loft insulation in a typical semi-detached home would cost around £480 in October 2022, but once it’s done you’d save £355 a year on your energy bills. So in less than 18 months you’d be making a saving.
Professional installation in a detached home would cost more – around £630 – but the savings are as much as £590 a year. And you’ll be saving around 1,000kg CO2 emissions from being released.
So it’s a win-win: you’ll waste less energy and be able to run central heating more cheaply – and break even relatively quickly.
Plus, you’ll be ready for whatever comes next. The central heating options of the future will operate more cheaply if homes can retain heat. Technology like heat pumps are able to operate efficiently because they’re designed for well insulated properties.
Types of insulation include:
- Loft and roof insulation. Heat rises, so trapping it from above is crucial.
- Floor insulation usually comes next, and it 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 within or outside a wall that’s not eligible for cavity wall insulation. It’s very expensive to install, so a longer term investment.
The energy efficiency of your home or of the home you’re renting is quantified by an EPC certificate. Find out how to get assessed and what the ratings mean here.
10. Update windows with double glazing or alternatives
Windows are a source of heat loss in any home. But if you have single glazing, you’ll notice you need much more energy to heat your home sufficiently. Double or even triple-glazing windows will reduce your heating needs dramatically.
Installing A-rated double glazing could save between £95 and £115 a year on the heating bill of a typical home. However, it doesn’t come cheaply.
We ask Which? members to rate the double glazing companies they’ve actually used.
Find out the best and worst double glazing companies for 2022 and more on how to buy double glazing.
If you need a quick fix and don’t have the money to spend, window foam seal, foam sealant or metallic brush strips can all help.
We’ve tested secondary glazing film in the past, like clingfilm for your windows, but we thought it wasn’t very resilient. It also needed re-stretching with a hair dryer periodically.
Thick curtains across windows can make a big difference too. Drawing them creates a barrier between your room and the elements and keeps your heat inside.
11. Explore home grants
If you’re replacing your heating system, the government’s Boiler Upgrade Scheme helps you to decarbonise with a heat pump if your home has no outstanding insulation recommendations.
With the latest price cap, a heat pump needs to run at an efficiency of 280% to have parity with a gas boiler’s running costs. Heat pumps can run at 300-400% efficiency, so they can prove cheaper to run.
Other grants can help if you’re in a vulnerable situation, such as:
- Cold weather payment to top-up your energy bills during cold snaps.
- Winter fuel payment to help people born before September 1955 pay their energy bills.
- Fuel Direct lets you deduct essential bills directly from income support, Universal Credit and other assistance available to you. The amount is decided by Jobcentre Plus or your pension centre.
Read our advice on home grants to find out what you’re entitled to.
The government’s 2022 Energy Price Guarantee and Energy Bill Support Scheme will both provide households in the UK with a bit of extra help this winter.
Find out everything you need to know about the government’s winter 2022 cost of living support and how it will be paid to you.
If you are struggling to afford your energy bills and feel you need urgent support, head to our guide to what to do if you can’t pay your energy bills.
