With the price cap having gone up again this month, it's a reasonable time to look at what's actually worth doing to bring a heating bill down, rather than reaching for whatever tip is doing the rounds. Some of the most commonly repeated advice is genuinely useful; some of it is weaker than it sounds. Here's what's actually backed by good evidence, roughly in order of "free and quick" to "takes a bit more effort."

1. Turn down your boiler's flow temperature, not just the thermostat

Most combi boilers arrive set to heat water to around 80°C before sending it to the radiators, which is hotter than most homes actually need. This is different from your room thermostat: the flow temperature is a setting on the boiler itself, usually accessed via a dial or a menu on the front panel.

You'll see this tip quoted as saving anywhere from 4% to 9% on gas use, and it's worth being clear about which figure is solid. Nesta, the innovation charity behind the original research, found that turning the flow temperature down to 60°C improves boiler efficiency by close to 4%. The more widely quoted 9% figure (around £65 a year for an average household) blends in other factors and assumes the boiler was previously running considerably hotter, so it's better treated as a ceiling than a guarantee. Either way, it costs nothing to try, and it takes a few minutes.

2. Take one degree off your room thermostat

This is the highest-value five minutes most households can spend. The Energy Saving Trust estimates that dropping your thermostat from 22°C to 21°C saves around £90 a year for a typical home, and each further degree saves roughly the same again. Most people can't actually tell the difference between 21°C and 22°C in the room, but the boiler notices immediately, since it's working less to close a smaller gap.

3. Draught-proof the obvious gaps first

Before spending on anything bigger, it's worth dealing with the places heat visibly escapes: letterboxes, keyholes, gaps under external doors, and old-style loft hatches. None of this requires a tradesperson. Draught excluders, letterbox brushes and basic sealant strips cost very little and directly reduce how hard your heating has to work to maintain the same temperature, which compounds with both tips above rather than competing with them.

The myth we're putting right

"Leaving the heating on low all day is cheaper than turning it on and off."

For most homes, no. The Energy Saving Trust is direct about this: heat leaks out of a building constantly, at a rate that depends on how well insulated it is, so keeping the heating running all day means paying to replace heat you're losing all day, not just when you're using it. Heating on a timer, only when the home is occupied or about to be, uses less energy overall than a slow constant trickle. There's a genuine exception worth knowing: some heating engineers note that in poorly insulated homes, or homes prone to damp, switching heating fully off can let condensation build up in the walls, which itself causes heat loss. If that sounds like your house, the fix is usually better insulation, not leaving the heating on permanently to compensate for it.

4. Check whether you're due the Warm Home Discount

If your household receives Pension Credit, Universal Credit, or certain other means-tested benefits, you may be entitled to a one-off £150 credit on your electricity bill under the Warm Home Discount scheme, which reopens for applications from October. Most eligible households in England and Wales receive it automatically, based on DWP records, with the credit applied to bills between November and the end of March. It's worth checking your eligibility directly on GOV.UK rather than assuming you don't qualify, since the criteria have changed in past years and this is money that, unlike most tips here, doesn't require you to do anything except claim it.

Where to start on the site

If you haven't already, last issue covered what the energy price cap actually caps, which is worth reading alongside this if you want to understand what these tips are actually working against. And if you haven't checked your current tariff against what's available recently, our energy comparison is the place to do that.

This article provides general educational content, not personalised financial or energy advice. Figures cited are averages from third-party research (Nesta, the Energy Saving Trust) and government schemes; individual savings and eligibility will vary, and scheme rules can change.