Why it doesn’t pay to leave your heating on low all day

Cost of heating, woman turns on radiator

Many people believe that it’s cheaper and more efficient to leave heating on all the time on a low setting rather than heating up rooms on a higher setting as you use them.

It’s a reasonable theory but according to the experts, it’s not true. The Energy Saving Trust (EST) says it’s generally better to heat your home only when you’re using it.

The reason is that all homes will lose heat constantly through walls and windows etc even if they are well insulated. The longer the heating is left on, the more heat is lost. This amounts to wasted energy and therefore wasted money.

If you only heat your home while you’re using it, the amount of time the heating is on is reduced and so is the heat loss.

This approach was backed up by Martin Lewis, presenter ITV’s Martin Lewis Money Show.

Appearing on ITV’s This Morning, he said: “You pay to pump energy in as and when it is needed, and to keep pumping it in constantly isn’t efficient.

“Using a timer’s best, because your thermostat is designed to turn your heating on and off to keep your home at the temperature you set it at. So in general I’d stick with that.”

There are exceptions, however, and it may sometimes be necessary to leave heating on while you’re out to avoid condensation. The build-up of water can cause dampness and mould, which may eventually lead to problems that are too expensive to repair.

Condensation is most obvious when it appears on windows, but it also clings to the surfaces of walls and can even penetrate into the mortar, reducing the efficiency of the insulation.

When you eventually turn on your heating, radiators will first have to generate energy to evaporate the condensation before they can start to heat your home.

Over time, condensation can also get inside plugs and electrical equipment causing rust and corrosion.

If condensation is a problem, or if some rooms in your home are left empty for long periods, it may be necessary to leave the heating on occasionally but for most circumstances, the message from experts such as those the EST is that it’s better to only turn on the heating while your home is being used.