Five Household Energy Myths Explained

At a glance

  • Heating advice depends on the building, heating system and people using it; one rule rarely suits every home.
  • On simple heating controls, a higher thermostat target is not a special fast-heat setting.
  • Smart meters measure use; the tariff and consumption determine the bill.
  • Reducing use must not compromise warmth, ventilation or essential equipment, and the price cap is not a maximum total bill.

Energy-saving suggestions are often passed on as universal rules. The difficulty is that a useful idea for one home can be unsuitable for another. These five common claims need context before you act on them.

On this page

Myth 1: Leaving the heating on low all day is always cheaper

Maintaining warmth in an empty building still requires energy to replace heat loss. With a conventional boiler system, suitable time and temperature controls can avoid heating when it is not needed.

That does not mean every system should be switched fully off whenever someone goes out. Heat pumps, storage heaters, slow-response buildings, frost protection and health needs can require different strategies.

The Centre for Sustainable Energy discusses heating myths, while Energy Saving Trust explains heat-pump controls. Follow the guidance for your actual system rather than applying a slogan about leaving it “on” or “off”.

Consider the length of the absence, how quickly the building cools and how it reheats. The aim is suitable comfort with less unnecessary heating, not the lowest possible temperature regardless of consequences.

Myth 2: Turning the thermostat right up always heats a room faster

With a simple on/off room thermostat, the setting is mainly a target. If the room is below the target, the thermostat calls for heat. Raising the target far above the temperature you want can mean the heating continues for longer and the room overshoots.

For example, choosing 28°C when you want 20°C can leave you relying on remembering to turn it back down. Setting an appropriate target and schedule is a more reliable routine.

Some modulating and weather-compensated controls behave differently, so this explanation is not a technical rule for every heating system. Read the manufacturer’s instructions or ask the installer. Energy Saving Trust explains programmers, thermostats and radiator controls.

Do not confuse the room target with boiler flow-temperature settings. They control different things, and unsuitable adjustments can affect performance or hot-water arrangements.

Myth 3: A smart meter automatically makes your tariff more expensive

A meter records consumption; a tariff sets the prices charged. An accurate bill can be higher than earlier estimates without the meter having made the same energy more expensive.

If a bill changes after installation, compare the tariff, readings, old closing meter reading, new opening reading and account adjustments. Check whether an estimate was corrected or a tariff changed around the same time.

Smart meters can make consumption easier to see, but visibility does not guarantee a saving. A display cost can also be inaccurate if its tariff information is wrong. Government troubleshooting guidance distinguishes display problems from meter problems. Read our full smart-meter guide for the separate checks.

Myth 4: Turning off every radiator in unused rooms is always best

Heating less-used rooms less can reduce unnecessary demand, but the whole building and system still matter. Heat moves between rooms, and very cold areas can create comfort and moisture problems.

Radiator valves, the main thermostat and any zoning controls need to work together. Closing a radiator beside the main thermostat can change how that control responds. Systems may also need particular flow or bypass arrangements; do not close everything without checking the instructions.

Keep rooms appropriately ventilated and avoid leaving parts of the home persistently cold and damp. Seek help if condensation or mould is a problem. A simple room-by-room temperature routine is more useful than an automatic rule that every unused radiator must be off.

Myth 5: The energy price cap limits your winter bill to the advertised amount

The headline cap amount is an illustration for specified typical consumption. It is not a personalised limit on what you can be charged in total.

A household using more energy can pay more even when its tariff meets the cap. Winter heating demand can also be much higher than summer use. Fixed tariffs and business contracts are not directly protected in the same way as eligible domestic default tariffs.

See Ofgem’s explanation of the cap and our guide to interpreting the headline figure. For Northern Ireland, use the separate local guidance rather than assuming the Great Britain system applies.

Better questions to ask

Instead of following a universal tip, ask:

  • What type of heating and controls do I have?
  • Which rooms need warmth, at which times, and for whom?
  • Has measured kWh changed, or only the price or payment?
  • Is equipment running unnecessarily, or serving an essential purpose?
  • Could the suggested change affect ventilation, moisture or safety?
  • How will I check the result over a comparable period?

Avoid judging an improvement solely from one lower monthly bill. Weather, time at home, prices and billing adjustments can all affect it.

Keep warmth and support in the picture

If someone is vulnerable to cold, prioritise suitable indoor conditions and appropriate advice. UKHSA’s cold-weather guidance explains the health risks and recommends aiming for at least 18°C in regularly occupied rooms, while considering individual needs.

If adequate heating is unaffordable, contact the supplier and seek independent support. A household facing high essential demand needs more than a list of habits to change.

Sources and further reading

Browse the Hub: Household resources · Environmental resources

Contributors

Scroll to Top