Is It Cheaper to Leave My Heating on All Day?

The idea that leaving your heating on all day is cheaper than turning it on and off as needed is a common question, especially during the colder months. Whilst there are a few factors to consider - the type of heating system and insulation for example, the short answer is no, it’s generally not cheaper to leave the heating on all day, and below we shall delve into why that is the case.

The Argument for Leaving the Heating On

The argument behind keeping your heating on all day is that it prevents your home from cooling down too much. Proponents say that reheating a very cold house takes more energy than maintaining a consistent temperature throughout the day. This approach might seem convenient, as it avoids the discomfort of waiting for the house to warm up.

However, most experts agree that it’s usually cheaper to heat your home only when you need it. According to the Energy Saving Trust in the UK, the best way to save energy (and money) is to use your heating system only when required, rather than leaving it on all day. This is because turning the heating on, when necessary, allows the system to work efficiently and avoids wasting energy keeping the home warm when you’re not there or don’t need the heat. The heat lost from your home is proportional to the difference in temperature between the inside and the outside. This means the warmer your house is, the faster it loses heat to the outside environment.

How Heating Works and Why It Matters

Most homes have a heating system that heats the air (or water) to a set temperature. Once the home reaches that temperature, the system shuts off and only turns on again when the temperature drops. If you leave the heating on all day, the system will constantly switch on and off to maintain that temperature, consuming energy each time.

Turning the heating on only when it is needed like when using a programmable thermostat that heats the house at set times is usually more energy-efficient and cost-effective. That way, you avoid heating your home when no one’s there to benefit.

Smart Use of Thermostats

The ideal strategy for saving money is to use your heating system efficiently. Programmable thermostats are a great solution because they allow you to set the heating to come on just before you wake up or return home. Smart thermostats can even learn your habits and adjust automatically, ensuring your home is warm when you need it and saving energy when you don’t. Some models even allow you to control your heating remotely via your smartphone.

Heat Loss and Insulation 

Heat naturally escapes from your home through walls, windows, and roofs. If your home isn’t well-insulated, the heating system has to work harder and consume more energy to maintain the temperature. The longer you leave the heating on, the more energy you lose to this heat escape. It’s like having a leaky bucket: the more you keep pouring water (or heat) in, the more you waste. Insulation is key to improving energy efficiency, but even in a well-insulated home, leaving the heating on all day would still use more energy than turning it on only when needed.

Remember that loft insulation isn’t the only highly effective method for making long-term savings on energy bills. You'll need to consider things like wall insulation, ensuring your windows and doors are draft-free for example.

An uninsulated home loses (rough figures that can vary with different house types and construction methods):

Ultimately then, the key to cost-effective home heating isn’t to leave the system on all day every day. Insulating your home properly and using a programmable or smart thermostat are the best strategies for staying warm while keeping costs down. 

Turning your heating on and off based on your schedule is the more efficient (and cheaper) approach. Keep in mind that proper insulation and efficient heating systems play a big role in how much energy your home consumes, no matter when you use the heating.