The most economical way to use your central heating over winter
05 November 2021 | Stephen Marcus
There can be lots of things to think about, when it comes to the efficiency of your central heating. All sorts of questions might crop up. Like, should you keep the heating on low all day, rather than switching it on and off as needed? And is it worth investing in improving insulation? Here, we try to answer a few of these.
What are the key tips for using central heating efficiently?
Here are the 3 things to consider for running your heating as efficiently and cost-effectively as possible:
1. Setting your boiler correctly
Most traditional central heating systems are controlled by a boiler. The temperature that you set your boiler at is the temperature it heats the water to (this temperature needs to be set on the boiler itself – not on your thermostat).
The key thing here is to set the boiler’s temperature no higher than needed – the ideal setting is around 70C for heating, and 60C for hot water.
2. Setting your thermostat correctly
There’s a common misconception that turning the thermostat up higher will make the heating warm up faster – sadly, this isn’t the case. What the thermostat does is measure the temperature of the room, and once the chosen temperature has been reached, it tells the boiler to stop sending hot water to the radiators.
So it’s best to just set the temperature to the level you want. We'd recommend keeping it around a safe, comfortable temperature of 18C to 21C.
3. Using thermostatic radiator valves
One way to get extra control over your heating is by using thermostatic radiator valves (TRVs). If you’re able to get these, they allow you to adjust the temperature of individual radiators – which means you can turn them up or down as needed, or off completely when they’re not in use. This all helps save energy.
Is it more energy efficient if I leave the heating on low all day, or turn it up only when I need it?
We think it’s most efficient to turn it on only when needed, instead of keeping it on low all the time. We also think this is more cost effective too. We’d recommend using a heating timer and your thermostat to do this.
The idea that leaving the heating on all the time is more efficient is a bit flawed. That’s because it doesn’t account for the fact that heat is always being lost when the heating is on – even in the best insulated houses. Here’s what happens:
- The colder it is outside, the more heat will be lost. During the winter months, when it’s much colder outside than it is inside, unfortunately heat will be lost whenever the heating is on.
- This means that the longer you have the heating on, the more heat will be lost. That’s because your heating will need to power up at regular intervals, to make up for the warmth that’s escaped.
If a house is poorly insulated, the heat loss will be greater, as the central heating might be using energy constantly, to maintain an even temperature. This would work out much more expensive than turning it on and off when it’s needed.
My house is really well insulated, with triple glazing, loft and wall insulation, and draught excluders. Will it still lose heat?
Unfortunately it will still lose a bit of heat, we’re sorry to say. For instance, even if you always keep the windows closed, you’ll still need to open the front door sometimes.
But there’s no doubt that insulating helps a massive amount, by stopping as much heat loss as possible – so it’s a really good idea to insulate, if you can afford to.
Which parts of my home can I insulate?
If you’re able to, there are lots of parts of your home that can be insulated. You can insulate your home’s walls, roof, windows, and doors. There are smaller changes and bigger changes that can be made, and any insulation will help your home use less energy for heating.
For more ways to cut your energy use, see our handy guide on energy saving tips.
What’s the best way to insulate my home?
These are some of the most effective ways to prevent heat loss:
- Cavity wall insulation is a highly efficient way to stop heat escaping
- An adequate thickness of loft insulation will also really help
- Buying or making draught excluders for doors and windows – you can even follow this guide to make your own
- If you can, get an eco-flap, to stop warm air escaping through your letterbox
- Filling in those draughty gaps between skirting boards and floorboards
How can I improve the energy efficiency of my heating system?
Here are a few things to think about:
- If your boiler needs replacing, it’s worth getting a more energy-efficient model if you’re able to. Replacing an old G-rated boiler with a modern A-rated condensing boiler can save energy.
- If it’s not time to replace your boiler, there are ways to make sure it’s running as efficiently as possible: here’s our guide to boiler efficiency and how to improve it.
- If you have a system boiler, help prevent heat loss from your hot water tank for longer by adding a cylinder jacket, if you can. Less energy will be wasted heating it, and it could save you about £20 a year.
- Insulating any hot water pipes that are visible around your home is a good idea, if you can – these are any pipes you can see, so not the ones in the walls, or under the floorboards. Pipes lose heat if they’re out in the open.
For more ideas, see our guide to making your home more energy-efficient.
And if your boiler stops working, read our practical guide on common boiler problems and how to fix them.
Other FAQs on how to save energy in winter
Should I keep the hot water boiler on all the time, or turn it on and off as needed
This really depends what type of system you have. If you have a gas, oil or liquefied petroleum gas (LPG) system, we recommend using a timer, so that it’s on when you need it.
But if you use an electrical immersion heater, it could be worth heating your water during the night. Especially if you have a time-of-use tariff such as Economy 7, where energy is cheaper at night.
Read our guide to Economy 7 tariffs and meters, and how it all works.
Will smart meters help me save money?
Smart meters can help you save energy, as they show your energy use in real time – which makes it easier to spot ways to save on costs too. They won’t guarantee savings but we do think they’re really helpful.
If you’d like one, you can get a smart meter installed free with OVO – book a smart meter installation here.
Should I turn individual radiators up and down, rather than using the main thermostat to control all of them?
If you can, using radiator valves to adjust the temperature of individual radiators is a really good idea. This means that none of them are heating an empty room, and using energy where they don’t need to.
Problems with your radiators? See our guide on how to bleed a radiator in 7 easy steps.
What is the difference between controlling the heating using the thermostat or radiator valves?
Radiator valves control the heat of the radiator they’re connected to – while thermostats control a larger area of the home.
If you’re trying to decide whether it’s better to use your radiator valves or your thermostat to control the heating, there are a few things to consider:
- Do you have multiple thermostats? If the answer is yes, then you may have less need to use radiator valves. This is because the different thermostats will enable you to adjust the temperature in different parts of the home.
- If you just have one thermostat for your entire home, there could be great advantages to using radiator valves, as well as your thermostat. This is because they let you control the temperature room by room.
If my heating is on, should I keep doors open or closed for each room?
We’d recommend keeping them closed. Most heating systems work by creating a “convection current” in a room. This means that hot air rises, moves round the room, sinks down, and travels back to the heater to be warmed up once more.
Closing the door means this cycle isn’t disturbed, so the room stays as warm as possible.
Is a combi boiler cheaper to run?
Whether a combi or a regular boiler is cheaper to run will depend on how much hot water you need. Standard boilers heat water and keep it in a tank for when you need it, while combi boilers heat up water instantly.
- For small households that don’t use a lot of water, a combi boiler could be the best choice, as hot water won’t be left to go cold in the tank
- For large households that use a lot of water, a regular boiler with a well-insulated tank could be the better option, as combi boilers tend to be less efficient at heating water
Either way, having the most efficient boiler possible makes a huge difference. Aim for an A-rated condensing boiler if possible, when it’s time to replace your boiler.
Still have questions on which is the best boiler for you? We've put together a quick guide on the different types of boiler and how to choose the right one for you.
Should you leave your heating on if you’re going away?
In the winter, frozen pipes can cause hundreds of pounds of damage – so it’s definitely recommended to time your heating to be on to some degree, even if you’re going to be away.
We’d recommend checking your home insurance policy before you go. Often they’ll ask that heating is kept to a minimum of 12C.
Want to save energy? A smart meter can help
These gadgets show your energy use in £ and p, making it easier to track how much it’s costing and spot ways to save. They also send your meter readings automatically – which means you don’t have to. Get a smart meter installed for free here.