Flick the switch: when to turn the heating on this winter 

With an increasingly changeable weather pattern – cold one week and warm the next – it isn’t easy to know when to flick that switch. However, we can make a judgment based on the outside temperature.

While each person’s temperature comfort zone varies, Martyn Bridges, technical director of marketing communications at Worcester Bosch, says: “Temperatures that are constantly below 15°C-16°C (59°F-61°F) throughout the day tend to make people feel cold.”

So, once the outside temperature drops to the mid-teens, you don’t need to feel guilty about turning on the heating.

“Although there isn’t an optimum time to switch on the heating,” says John Lawless, content manager at Best Heating, “most people will begin to use their heating regularly around the middle of October.”

Before this, the majority will try other methods to keep warm, “but by the end of October, even the hardiest among us will have their central heating switched on,” he adds.

Matthew Jenkins, Heating Expert at MyJobQuote, agrees: “Outdoor temperatures of 15 degrees is when most people notice a change in temperature enough to comment on their discomfort. This year, we’ll see daytime temperatures drop to below 15 degrees on the last weekend of October, making it the optimum time to turn the heating on.”

Apart from outside conditions, the temperature in your home will play a big part, too. If it’s well insulated, with a good level of glazing and loft insulation, you can hold off from turning your heating on for a little while longer.

Whether you keep your heating on all day, or switch it off at certain times, will depend on your household’s needs and heating system.  

And while you might think it’s cheaper to keep the heating on low when you go out, rather than turning it off, it’s not. “The general rule of thumb,” says Lawless, “is that you should turn your heating off completely when not at home, so as not to  waste energy and make your bills needlessly high.” 

From a cost perspective, the Energy Saving Trust agrees: “It’s cheaper to reheat your home than it is to keep it on low all day when you’re not there.” 

But there is an exception to turning off your heating when you go out. “If you have a heat pump, these are more efficient if you leave them running for longer at a lower output,” the Energy Saving Trust adds.

If you’re unsure as to what temperature to set your thermostat, it’s worth knowing what the health experts advise. The Energy Saving Trust says: “For most, the lowest comfortable temperature to set your heating to is between 18°C-21°C (64°F-70°F), as the World Health Organisation advises.”  

Lawless says: “The average thermostat setting in the UK is 20.8°C (69.4°F). However, 18°C (64°F) is warm enough to remain comfortable in winter.” 

To help find the perfect temperature, Lawless suggests positioning the thermostat in a place that isn’t blocked by curtains or furniture, so air can flow around it and measure the temperature of the space properly. 

Stepping out from the snug comfort of a warm bed into a cold room is not the best wake-up call in the morning. For this reason, it’s worth setting your heating to come on before your alarm wakes you up. 

Will Davies, CEO of property maintenance company Aspect, advises: “The optimal time for heating to turn on before you wake up varies from person to person. Some prefer a toasty warm environment, while others are comfortable with a slightly cooler start to the day. Typically, setting the heating to come on 30 minutes to an hour before you wake up is a good starting point.” 

“If the overnight forecast is anything below 5°C  (41°F), you’ll definitely benefit from an hour’s blast of heat in the morning to take away the chill,” says Lawless. 

However, there’s no need to keep the heating on once you’re in bed. You can switch it off an hour before you turn in.  

If you’re planning on being away from home for an extended period while the weather is cold, it’s a good plan to set your heating to come on at least once a day while you’re away. This will help to prevent any unwanted problems.  

The Energy Saving Trust suggests setting your thermostat to 5°C (41°F) to prevent pipes from freezing, but this depends on the boiler’s age. It says: “Modern boilers also often have inbuilt frost protection to stop the water in the boiler dropping below freezing.” 

How do these work? “If the temperature drops too low within the house, the heating system will turn on, even if programmed to stay off,” explains Bridges.  

Whether you’re going away or not, the experts advise you to get your boiler serviced regularly. This will help avoid breakdowns and expensive callout fees in the depths of winter.  

It’s important to look after your health and keep warm when the temperature drops. “A temperature below 15°C (59°F) makes the body more susceptible to respiratory diseases, and the chance of increased blood pressure or cardiovascular disease increases significantly for a home that is below 13°C (55°F),” says Lawless.  

The NHS has some further advice on keeping well during the winter.