A new boiler is the biggest single improvement you can make to heating efficiency — but there's plenty you can do to reduce bills without replacing the boiler.
1. Install a smart thermostat
Replacing an old mechanical programmer with a smart thermostat (Nest, Hive, or Tado) is the single most impactful thing you can do without replacing the boiler. Smart thermostats learn your habits and stop heating empty rooms. Average savings: £75–£150/year.
2. Fit thermostatic radiator valves
TRVs on every radiator (except the one in the room with the main thermostat) let you heat rooms to the temperature you actually need, not the maximum boiler output. Spare bedrooms set to 1–2, living areas to 3–4. Potential saving: £50–£100/year.
3. Reduce your thermostat by 1°C
Lowering your main thermostat from 20°C to 19°C typically saves around 6% on heating costs — approximately £90/year on an average bill. Most people don't notice the difference in comfort.
4. Bleed radiators regularly
Trapped air reduces radiator efficiency. Bleed all radiators at the start of each heating season. This simple task costs nothing and takes 20 minutes.
5. Check your boiler pressure
A boiler running at low pressure works harder than it needs to. Check monthly and repressurise if below 1 bar.
6. Insulate your hot water cylinder
If you have an old uninsulated hot water cylinder, a modern factory-insulated cylinder jacket reduces heat loss dramatically. Or consider upgrading to a new cylinder entirely.