How to Save on Your Gas Bill With a Combi Boiler Heating System

Practical Money-Saving Advice for UK Homeowners

With energy prices fluctuating and household costs rising, finding ways to reduce your gas bill has never been more important. If your home uses a combi boiler heating system, you’re already benefiting from one of the most efficient heating solutions available — but with the right habits and setup, you can save even more.

Below are proven, practical ways to cut your gas costs while keeping your home warm and comfortable.

1. Use Your Thermostat Strategically

Your thermostat plays a major role in how much gas you use.

• Reducing your thermostat by just 1°C can lower heating bills by up to 10%

• Set heating to come on only when needed (mornings and evenings)

• Avoid leaving the heating on all day when no one is home

Upgrade to a Smart or Programmable Thermostat

These allow you to:

• Control heating remotely

• Set accurate schedules

• Automatically adjust temperatures to suit your routine

Smarter control means less wasted gas.

2. Keep Your Combi Boiler Well Maintained

A poorly maintained boiler uses more gas to produce the same heat.

Essential Maintenance Tips

• Service your boiler once a year

• Bleed radiators to remove trapped air

• Check boiler pressure regularly (low pressure reduces efficiency)

A well-maintained combi boiler can operate at 90%+ efficiency, while neglected systems waste fuel and money.

3. Only Heat the Rooms You Use

Combi boilers work extremely well with thermostatic radiator valves (TRVs).

Use TRVs to:

• Turn down radiators in unused rooms

• Keep living areas warm

• Maintain cooler temperatures in bedrooms

This prevents you from paying to heat empty spaces.

4. Improve Your Home’s Insulation

Even the best combi boiler can’t overcome poor insulation.

Focus On:

• Loft insulation (one of the biggest money savers)

• Cavity wall insulation

• Sealing draughts around doors and windows

A well-insulated home holds heat longer, meaning your boiler runs less and uses less gas.

5. Use Hot Water More Efficiently

Combi boilers heat water on demand — already an energy-saving advantage — but habits still matter.

Simple Changes That Save Money

• Take shorter showers

• Fit water-saving showerheads

• Fix dripping hot taps (they waste both gas and water)

Hot water accounts for a significant portion of household gas usage.

6. Don’t Block Your Radiators

Radiators need space to work efficiently.

• Avoid placing furniture directly in front of them

• Don’t dry clothes on radiators

• Fit radiator reflector panels behind external-wall radiators

Better airflow means rooms heat faster and your boiler runs for less time.

7. Upgrade If Your Boiler Is Over 10–15 Years Old

Older boilers can be as little as 60–70% efficient. Modern A-rated combi boilers exceed 90% efficiency.

Upgrading Can:

• Reduce gas bills significantly

• Lower breakdown risk

• Improve heating reliability

• Reduce your carbon footprint

While the upfront cost is higher, long-term savings are often substantial.

8. Monitor Your Gas Usage

Awareness leads to better habits.

• Take monthly gas meter readings

• Use your energy supplier’s app if available

• Compare seasonal usage

Monitoring usage helps spot waste early and encourages smarter energy use.

Final Thoughts

A combi boiler is one of the most cost-effective heating systems available — but how you use it makes all the difference.

By combining:

• Smart thermostat control

• Regular boiler maintenance

• Good insulation

• Efficient heating habits

You can significantly reduce your gas bills without sacrificing comfort.

Small changes made consistently can add up to big savings over the year.