What Is Eco Mode on My Boiler?

If you’ve spotted an ‘Eco Mode’ button on your boiler and wondered what it actually does — you’re not alone. Most modern combi boilers have this feature, but it’s not always clear whether you should use it or leave it off.

Here’s what Eco Mode does, when to use it, and whether it’s right for your home.

So, What Does Eco Mode Actually Do?

Eco Mode changes how your boiler heats hot water. When it’s switched on, your boiler stops keeping a small amount of water warm at all times. Instead, it only fires up when you actually turn on a tap.

That means it uses less gas in the background — but you might have to wait a few seconds longer for the water to heat up.

What Are the Benefits of Using Eco Mode?

• Lower gas usage: Your boiler isn’t constantly using energy to keep water pre-heated.
• Smaller bills: Great if you’re looking to cut down your heating costs.
• Efficient for light use: Ideal for homes that don’t use hot water constantly throughout the day.

What’s the Downside?

Hot water takes a little longer to come through — especially in the mornings or after a few hours of no use. That’s because the boiler starts from cold rather than using pre-heated water.

For most people, it’s just a short wait — but if you need instant hot water for small children, older family members or a busy household routine, you might prefer to leave Eco Mode off during peak times.

When Should You Use Eco Mode?

Eco Mode is a smart choice if:

• You’re not using hot water constantly all day
• You want to reduce your energy use
• You’re happy to wait a few extra seconds for hot water

You can also turn it on when you’re going away, or during summer when hot water use is lower.

Does Eco Mode Affect My Heating?

Nope — Eco Mode only changes how your boiler deals with hot water. Your central heating will still work exactly the same, based on your thermostat and heating schedule.

Should I Leave Eco Mode On All the Time?

If it suits your lifestyle — go for it. It puts less strain on your boiler, can reduce wear on parts, and helps save on energy bills. You can always switch it off temporarily if you’re expecting guests or using lots of hot water that day.

Want to Save Even More?

Eco Mode is a great start, but there’s more you can do to boost efficiency:

• Annual boiler servicing keeps everything running efficiently
• TRVs (thermostatic radiator valves) help you control room-by-room temperatures
• Smart thermostats give you full control, even when you’re not home

We help homeowners across Dunfermline and Fife heat smarter, save money, and stay comfortable — all year round.