Consumer expert Grace Forrell, a regular on ITV's This Morning, has settled the debate over whether it is cheaper to leave heating on low all day rather than turning it up when cold. In an Instagram post, she said people make 'three mistakes' with how they use their heating.
Three common heating mistakes
Ms Forrell explained: "Number one, keeping your heating on low all day rather than turning it on and off. Unless you have a heat pump, it's almost always cheaper to turn it off when you're not in and you don't need it. So, use your timers so you don't forget."
"Number two, cranking your thermostat up to a high temperature thinking it will heat a cold house more quickly. Your house won't get warmer any quicker by doing this, but it will push your heating costs up."
"And number three, using a hot water bottle and an electric blanket at the same time. This is a massive hazard, so don't ever use them together. Pick one or the other."
Energy bills context
The advice comes as UK energy bills rise. The energy price cap increased by 3.6% (rounded to 4%) on 1 October 2026, bringing the average annual bill for a typical dual-fuel household paying by monthly Direct Debit to £1,723. Prices are predicted to rise by over 20% in January.
The Energy Saving Trust maintains that keeping the heating running all day is the less efficient option. It recommends heating your home only when required, so you pay solely for what you actually use.
It said: "Generally, you should put the heating on when you start to feel cold. This is especially important if anyone in your home is an older person or someone with a medical condition."
Boiler versus heat pump
On the question of leaving heating on all day versus turning it off and on, the EST said: "If you have a boiler, then no. Keeping your heating on all the time will use more energy and cost you more money."
"It's more energy efficient, and better for your bills, to have your boiler come on when you need it. But if you have a heat pump, then you can save money by leaving the heating on all day."
Safety and maintenance checks
Appearing on This Morning this week, Ms Forrell told hosts Cat Deeley and Ben Shephard: "It's really up to you when you choose to turn your heating on. From a safety point of view, you don't really want to be sitting in a room that's colder than 18° during the day."
"And if you're elderly or you have certain medical conditions, you want that to be a few degrees warmer is the minimum as well. But you can pick up decent room thermometers for around £10. You can get them on the high street or online and they can help you track the temperature inside so you know when to switch it on."
She also gave three rules for things people need to check: check carbon monoxide detectors, bleed radiators and clean them inside, and service the boiler. She explained that gas boilers should be serviced annually, and waiting until winter could mean high call-out fees and being without heating at the coldest time. She noted boiler servicing costs around £100, and advised using an engineer on the Gas Safe Register. For renters, the landlord is responsible for gas safety checks and boiler maintenance.
