With colder temperatures seemingly here to stay, many of us are thinking about our boilers more. Checking your boiler and central heating system are functioning properly and efficiently is crucial, as we rely on them to keep us warm over the winter.
But how confident and comfortable are you checking the health of your boiler and central heating system? This was just one of the questions British Gas asked 1,000 boiler owners across Britain to discover the nation’s levels of knowledge, confidence and understanding of boiler-related issues. Of those surveyed, more than half of Scots (51.9%) don’t know how to check the health of their boiler.
The full survey explored everything from how many cold showers people would endure before calling a gas engineer for help to how confident they would be bleeding their radiators.
British Gas also offers expert advice on how to check your boiler’s health, as well as how to maintain a healthy boiler throughout the year, which you can find below.
Key Findings:
More than half of Scots surveyed (52%) don’t know how to check the health of their boiler.
42% of Scots find boiler issues ‘stressful’ or ‘intimidating’.
Almost 3 in 10 of Scots ‘never think about their boiler’
46% of Scots would endure at least one cold shower before calling in a boiler expert.
More than half of Scots unsure how to check the health of their boiler
It is obvious from the survey that there are some confidence and knowledge gaps across the country when it comes to boilers. More than half (52%) of survey respondents admitted they don’t know how to check the health of their boiler.
Do you know how to check the health of your boiler?
Percentage of responses (Scotland)
No, I do not know how to check
51.9%
Yes, I check once per year
18.5%
Yes, I check it once per month
22.2%
Yes, but I never check it
7.4%
On top of this, more than two in five (42%) find boiler issues ‘stressful’ or ‘intimidating’, while over 28% of the Scottish public answered that they never think about boiler issues. That’s in comparison to only 30% that feel confident solving problems.
How do you feel about solving boiler-related issues
Percentage of responses (Scotland)
I find it stressful and intimidating
42.0%
I never think about it
28.4%
I feel confident
29.6%
How many cold showers would you endure before seeking emergency repair works?
To find out how long people are willing to ignore their malfunctioning boiler before calling for help, British Gas asked how many cold showers they would endure before seeking repair works.
Although the majority of Scots would not stand the thought of a single cold shower before picking up the phone to an engineer, there were some staggering findings to the contrary. 46% would endure at least one icy shower, with 1.2% answering they wouldn’t mind 10 or more before calling out for repairs.
How many cold showers would you endure before seeking emergency repair works?
Percentage of responses (Scotland)
Wouldn’t endure a single cold shower
54.3%
Would endure one or more cold showers
45.6%
Would endure two or more cold showers
14.7%
Would endure three or more cold showers.
6.1%
Would endure ten or more cold showers
1.2%
Expert commentary on boiler health from Joanna Flowers, a service and repair engineer at British Gas:
How can I check the health of my boiler?
With over 50% of people not understanding how to check their boiler’s health, it can feel puzzling sometimes. If you’re one of those people who aren’t too sure, you can do simple things like turning the heating on and checking radiators to ensure the system is working properly – especially if it hasn’t been turned on recently.
Bleeding your radiators is another simple task you could carry out to ensure your home heating system is functioning as it should. If your radiators are cold at the top and hot at the bottom, this could be something to try. To do this, turn off your heating, let your radiators go cold and then bleed them with a bleed key and cloth.
Remember that if your boiler does stop working, you can book a one-off emergency repair with British Gas before 11 am and they’ll be there the same day*
*Based on 2024 performance data, 80% of customers contacting by 11am received the same day service.
How often should I check my boiler?
While you don’t have to be an expert to check if your boiler’s working properly, there are lots of simple things you can do. Turn the heating on and feel the radiators to make sure the system is working properly – especially if it hasn’t been used in a while.
And when it comes to servicing, once a year is the right amount. We recommend that your boiler is serviced once a year, but if you want a more in-depth assessment by a professional who will make sure it’s all in working order, book a boiler service when you need it.
Whether you choose to do this in the summer, winter or at any time of year, annual servicing can prevent any unwanted breakages or faults before they happen.
What should I do if my boiler is making noise?
With over 12,000 searches a month across the UK for queries relating to boiler sounds, this is certainly something people worry about. While it can be a little concerning, don’t panic. Boilers make sounds, even when they’re switched on and being used. If you’re hearing a specific sound – banging, vibrating, whistling or any other noise – this may be a clue to what is going on inside your boiler.
Vibrating sounds coming from your boiler? With over 2,740 searches a month, steady and continuous noises can be common and may indicate loose brackets that need tightening or trapped air. If uncertain where it’s coming from, get an engineer to scan the source and diagnose any faults.
Mechanical sounds like banging, knocking and clunking are also a common concern, with over 2,200 searches a month. This can signal a faulty part inside a boiler or even a problem with the heat exchanger. It’s best to address these issues promptly so that you can put your mind to rest.
Since your boiler pumps a lot of water through the pipes in your house, hearing water and liquid sounds coming from the unit can be normal.
If you’re hearing something out of the blue or extremely loud, then it may be time to double-check that everything’s working okay. It’s important to remember that boilers will have automatic switches and safety mechanisms that turn the boiler off before it is dangerous. If this happens, get in a professional engineer to safely get your boiler working again.
Always book a gas safe engineer if you are not sure what’s wrong.
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.”
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).
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
