illions of hard-up families could save hundreds of pounds on their energy bills this winter in a few simple steps without making their homes any colder, experts have said.
Record-breaking energy prices are likely to affect many over the next few months as Ofgem is expected to hike its energy price cap on Friday.
Experts warn that worse is to come when the cap is updated in January.
But two small changes to the way your boiler works could save up to 18%, or around £324, according to experts at the Heating Hub, which provides advice on energy efficiency.
– Turning down your flow temperature
The flow temperature on a boiler regulates how hot the water is when it leaves the boiler to go to your radiators.
Most condensing combi boilers in the UK are still set to their factory setting, which tends to be around 80C, but at this temperature boilers cannot operate at their most efficient.
When a condensing boiler burns gas, a lot of the heat can escape out of the flue and out on to the street – this heat literally disappears into thin air.
Steam coming out of a flue is a sign that flow temperature is high and heat is escaping.
At lower temperatures the boiler works to recycle a lot of this heat back into the water it is trying to warm up.
Jo Alsop of the Heating Hub said that by turning down the flow temperature, households could save around 6% to 8% of their annual gas usage.
“It’s worth making the point that condensing boilers, even though they’re A-rated on the box (for efficiency), they don’t necessarily achieve A-rating in the home,” she said.
Some A-rated boilers have been found to operate at E-rated efficiency levels in the home, at just 75%.
Turning down the flow temperature is not the same as turning down the thermostat. The boiler and radiators will still work to keep rooms at the same temperature as before, but it might take a little longer for the house to heat up.
Ms Alsop said families should experiment with lowering the flow temperature. The colder it is, the more efficient the boiler will run.
“We would advise to do that to around 60C and if they find that’s a bit too cool on a very cold day, they can always notch it back up, but importantly reduce it down again when the weather gets a bit warmer, and keep reducing it down,” she said.
How to do this depends on the boiler, but it is a fairly simple process.
It should say how in the boiler manual, which can often be found online. The Heating Hub also has a guide on its website on how to change the flow temperature.
It is important to remember only to do this if you have a condensing combi boiler which is not connected to a hot water cylinder. Also be careful about keeping rooms cold if you have vulnerable people in the home.
Several energy suppliers are also keen for households to turn down flow temperatures.
Rebecca Dibb-Simkin, chief product officer at Octopus Energy, said: “Safely turning down the water flow temperature of your gas boiler is a little-known but very effective tip for saving gas whilst staying warm, and could save people up to 8% off their gas bills.
“Over 100,000 of our customers who took part in our energy efficiency scheme last winter told us they tried it, with some of them knocking nearly £100 off their bills.”
– Turning off your boiler’s pre-heat function
The pre-heat function on a boiler is designed to ensure that hot water is ready to flow to the taps at a moment’s notice.
It means the boiler always keeps a small amount of water hot.
It is a handy function when you want to wash your hands and do not want to wait for water to heat up, but the boiler is heating up water when you do not need it.
“If the boiler is not on and heating the home, it will fire anyway, just to keep that water at temperature, even if someone is not home during the day, and certainly it will fire all through the night, even when hot water is not in demand,” Ms Alsop said.
That means burning gas through the night, every night, for nothing.
Turning off the pre-heat function might mean a longer wait for the shower to get warm in the morning, but it is a small inconvenience for the hundreds of pounds that can be saved.
Ms Alsop estimates households could save around 5%-10% of their gas use.
Guides on how to turn off the pre-heat function should be in the boiler manual or online.
However Ms Alsop said people should consider turning the pre-heat on during droughts if they have to wait an exceptionally long time for hot water to reach the taps. They can still turn it off during the day and night.