Seven Energy and Heating Myths Inflating British Bills

Heating advice spreads fastest when it sounds logical, which is exactly why so much of it is wrong. A few of these myths actually increase gas use rather than reduce it, and the fix for several of them is a setting most households have never touched.

Myth One: Leaving the Heating on Low All Day Is Cheaper Than Scheduling It

This persists because a constant low temperature feels gentler on the system than firing up from cold. In reality, a well-insulated home loses heat to the outside continuously whenever the indoor temperature is above the outdoor one, so keeping it warm all day simply means paying for heat loss across more hours, including times nobody is home to benefit from it. A modern boiler with a programmable thermostat set to heat the home only around the hours people are actually in and awake will almost always use less gas than one running low-level heat continuously.

Myth Two: Turning the Thermostat Up Higher Heats the Room Faster

A thermostat is a simple on/off switch tied to a target temperature; it doesn’t control how fast the boiler fires. Setting it to 30°C instead of 21°C doesn’t speed up warming the room; it just means the heating stays on longer because it’s chasing a target you don’t actually want to reach. The room warms at the same rate either way, based on your radiators and boiler output, not the number on the dial.

Myth Three: A High Boiler Flow Temperature Makes Radiators More Efficient

Flow temperature is the temperature of water leaving the boiler for the radiators, and most combi boilers in UK homes are set from the factory much higher than they need to be, often well above 70°C. Lowering flow temperature to somewhere around 60°C or even lower, while keeping the room thermostat the same, can allow a boiler to run in a more efficient condensing mode for longer. This is one of the few genuinely under-used adjustments, and it’s usually just a dial or menu setting on the boiler itself.

Illustrative Example

If a household’s annual gas spend sits around £850 and adjusting flow temperature plausibly reduces consumption by a modest percentage, say in the region of 8% based on commonly cited ranges for this kind of change, that would work out as roughly £68 a year, as an illustrative figure only, not a guaranteed outcome, since actual savings depend heavily on the specific boiler, radiators and home.

Myth Four: Closing Radiators in Unused Rooms Always Saves Money

This is true only up to a point. Closing a radiator doesn’t stop that room losing heat to the outside; it just stops you replacing the heat that’s lost. If the room is next to a frequently used one, closing it can increase heat loss from the warm room into the now-colder one through the shared wall, partially offsetting any saving. It can still be worth doing for rarely used, well-isolated rooms, but it isn’t a universal rule.

Myth Five: Boiling a Full Kettle “Just in Case” Saves Time and Energy Overall

Overfilling a kettle for one cup wastes the energy used to heat water you then pour away, and this adds up more than people assume across a household making several hot drinks a day. Filling to just above the amount needed is a small habit with a real, cumulative effect, separate from heating costs but part of the same general household energy picture.

Myth Six: Draught-Proofing Makes No Noticeable Difference

Gaps around doors, letterboxes and old-style loft hatches let warm air escape continuously, and because this heat loss is gradual rather than sudden, it’s easy to underestimate. Simple draught-proofing strips and letterbox brushes are inexpensive relative to the ongoing heat loss they address, and the saving compounds every single day the heating is on, not just on particularly cold ones.

Myth Seven: Electric Heaters Are Always Cheaper Than Central Heating for One Room

This depends entirely on the relative price of electricity versus gas per unit of heat delivered, which varies and should be checked against current tariffs rather than assumed. A single electric heater can make sense for genuinely short, occasional use in one room while the rest of the home stays unheated. It rarely makes sense as a long-term substitute for heating a whole home if gas-fired central heating is already installed and reasonably efficient.

Myth Eight: Smart Thermostats Automatically Pay for Themselves Quickly

A smart thermostat can genuinely help by making scheduling easier and by offering features like geofencing or room-by-room control, but the saving it produces depends almost entirely on how the household was heating before installing one. A home that already used a basic programmer sensibly may see only a modest improvement, while a home that previously left heating running constantly out of habit may see a much larger change. Treat any payback period quoted by a manufacturer as an illustrative estimate based on specific assumptions, not a guarantee for every household.

A Short Practical Checklist

• Check your boiler’s flow temperature setting and consider lowering it gradually, watching for any change in comfort.
• Use a programmable thermostat or timer rather than leaving heating on continuously at a low setting.
• Draught-proof doors, letterboxes and loft hatches as a one-off, low-cost task.
• Keep radiators on in rooms adjoining frequently used spaces; be more selective about closing ones that are properly isolated.
• Compare gas and electricity unit rates on your own current tariff before assuming either is universally cheaper for a given use.

When to Bring in a Qualified Engineer Rather Than Guessing

Adjusting flow temperature and thermostat scheduling is generally safe to experiment with on most modern combi boilers, but if changes don’t produce the comfort or savings expected, or if a home consistently struggles to reach a comfortable temperature at all, that’s a sign worth investigating properly rather than continuing to tweak settings. Insulation gaps, an undersized boiler for the property, or ageing radiators can all mask the benefit of these adjustments, and a qualified heating engineer can diagnose that in a way a household generally can’t from the thermostat alone.

All figures here are illustrative examples used to demonstrate the method, not guaranteed savings. Energy prices, tariffs and the suitability of any adjustment depend on your specific boiler, home and supplier, so check current guidance or a qualified heating engineer before making changes that affect your system’s safety or warranty.