The energy price cap went up again on 1 October, and the gas unit rate has risen by almost 9%. With the clocks now back and the heating on most evenings, here are ten practical ways to keep your South West London home warm for less this winter.
If your latest energy bill made you wince, you are not alone. Ofgem's price cap for 1 October to 31 December 2026 has risen to around £1,723 a year for a typical household paying by Direct Debit, roughly £60 more than the summer. The bigger story is gas. The gas unit rate has gone up from 7.33p to 7.97p per kWh, an increase of almost 9%, while electricity has barely moved. Most homes in Wimbledon, Merton, Wandsworth and the surrounding areas heat their rooms and water with a gas boiler, so this is the rise you will feel most as the weather turns colder.
The good news is that you have more control over your heating costs than you might think. Many of the changes below cost very little, and several can be done in an afternoon. Here are ten of the most effective, starting with the free ones.
This is the single easiest saving for most homes, and it costs nothing. Many combi boilers are left at the factory setting, which sends water to the radiators at 70°C to 80°C. A modern condensing boiler only works at its most efficient when the water returning to it is cool enough to condense, which rarely happens at those temperatures. Turning the radiator flow temperature down to around 60°C lets the boiler condense more of the time and burn less gas, while your rooms still reach the same temperature, just a little more gently.
If you have a hot water cylinder rather than a combi, only adjust the radiator setting. Stored hot water should be kept at 60°C or above to prevent bacteria from growing. If you are unsure which dial does what, check your boiler manual or ask your heating engineer.
Thermostatic radiator valves, or TRVs, let you set a different temperature in each room. There is no need to heat a spare bedroom or a hallway to the same level as the living room. Fitting TRVs is a relatively simple job for a plumber, and they usually pay for themselves quickly. Leave one radiator without a TRV, normally the one in the same room as your main thermostat, so the system always has somewhere for water to flow.
An old dial thermostat and a mechanical timer cannot react to how you actually live. A smart thermostat lets you set schedules by room or by day, turn the heating off from your phone when plans change, and many will learn how long your home takes to warm up. Some models can also adjust the boiler output automatically, which works hand in hand with a lower flow temperature. Just as important, set your schedule so the heating goes off 30 minutes before you leave or go to bed, as the house will hold its warmth.
If the top of a radiator stays cold while the bottom is hot, there is air trapped inside and you are paying to heat a radiator that is only half working. Bleeding it with a radiator key takes a few minutes. If some radiators heat up quickly while others take an age, the system may need balancing so hot water is shared evenly around the house. Older systems in Victorian and Edwardian terraces often benefit from a power flush, a fresh dose of inhibitor and a magnetic filter to keep sludge away from the boiler.
A quarter of the heat in an uninsulated home can escape through the roof. The recommended depth for mineral wool loft insulation is 270mm, and many London lofts still have a thin, compressed layer from decades ago. Topping it up is one of the best value improvements you can make, and it is a job many homeowners tackle themselves. Remember to leave gaps at the eaves for ventilation, insulate the loft hatch, and use loft legs if you need to board over the top for storage so the insulation is not squashed.
Draughts around doors, sash windows, letterboxes, loft hatches and gaps in floorboards let warm air out and cold air in. Self adhesive seals, brush strips, letterbox covers and flexible gap filler are inexpensive and quick to fit. If you have an open fireplace you no longer use, a chimney balloon or register plate will stop heat disappearing up the flue. Do not block air bricks, trickle vents or extractor fans, though. Homes still need some controlled ventilation, and blocking it can lead to the condensation and mould problems we covered in our earlier guide.
Hot water pipes running through a cold loft, garage or under the floor lose heat all the way to the tap. Foam pipe lagging is cheap, takes minutes to fit and also helps protect pipes from freezing in a cold snap. If you have a hot water cylinder without a factory fitted foam coating, a cylinder jacket at least 80mm thick will keep the water hotter for longer, so the boiler fires up less often.
Radiators fixed to external walls lose a surprising amount of heat straight into the brickwork. Reflector panels sit behind the radiator and bounce that heat back into the room. They are especially useful in solid wall homes, which are very common across South West London. While you are there, make sure furniture and long curtains are not covering your radiators and trapping the heat behind them.
Heating water is one of the biggest uses of gas in the home after space heating. An aerated or water saving shower head can cut the amount of hot water you use in every shower without making it feel weaker. Tap aerators do the same at the basin and kitchen sink. Fixing a dripping hot tap and cutting a minute or two off each shower will also make a difference over a winter. If your shower or bathroom is due for replacement, it is worth choosing efficient fittings from the start.
If your boiler is more than 15 years old, it may be far less efficient than a modern condensing model, and it is more likely to let you down in the middle of a cold spell. Replacing a boiler is a bigger decision, so it pays to plan it rather than wait for a breakdown. Ask an installer about the options for your home, including low carbon systems such as air source heat pumps, which may qualify for government grants such as the Boiler Upgrade Scheme. It is also worth checking whether you are eligible for the £150 Warm Home Discount and whether your supplier offers any support funds.
You do not need to make every change at once. Start with the free ones, turn down the flow temperature, bleed your radiators and set a sensible heating schedule, then work through the rest as your budget allows. Small improvements add up, and many will keep saving you money for years.
Our Wimbledon trade counter stocks everything from loft insulation, pipe lagging and draught proofing to thermostatic radiator valves, smart controls, radiators and water saving showers. Pop in and speak to our team, who will be happy to help you choose the right products for your home and point you towards the jobs that will make the biggest difference.
Kate
I cannot rate Precise Supplies highly enough! Valdas is possibly the most helpful and kind person on the planet, and was really supportive in helping me choose everything for my new bathroom. Pricing and service both outstanding. Highly recommend!
– via Google
Kraig Brown
Hi my name is Kraig precise supplies best prices on the market, every order delivered on time and there customer service 10/10 cheers team 👍
– via Google
Portia Booroff
Excellent and supportive company. Brilliant staff. Eager to help and knowledgeable. Will definitely use again and I highly recommend them. Excellent standard of craftsmanship.
– via Google