How Much Can a New Boiler Save You?
A new boiler could save you £140–£327 a year when replacing an old gas boiler operating at 65% efficiency. Energy Saving Trust estimates savings of £420 a year when upgrading a G-rated boiler without heating controls to an A-rated boiler with full controls. Your savings depend on boiler efficiency, gas usage and heating needs. Find out how much your household can save by installing a new Boiler with the Boiler Savings Calculator.
Calculate How Much a New Boiler Could Save You
Is your old boiler costing you more than you think? Use our free calculator to estimate your potential savings.
- Choose your property size and existing boiler efficiency
- See your estimated monthly and annual gas savings
- Compare your savings over the next 10 years
- Find out whether a new boiler is worth exploring
Our free calculator estimates how much you could save on gas bills by replacing your existing boiler with a new A-rated model. The results are based on your home’s gas usage, current boiler efficiency and gas prices.
You could save even more with new, properly optimised heating controls, such as smart thermostats and zoned heating. These extra savings aren’t included in the calculator.
New Boiler Savings Calculator
See how much an efficient new boiler could save on your gas bills.
Your estimated annual gas saving
£222
Is a new boiler worth it for your home?
Compare your potential gas savings with the cost of replacing your existing boiler. TM Hughes offers free home surveys and no-obligation quotes across Essex.
Get a Free Boiler Survey & Quote*Illustrative estimates only. The calculator compares your current gas use with a new boiler operating at 92% efficiency, assuming the same heating and hot-water demand. It does not add any savings from new heating controls. Ten-year savings assume unchanged prices and usage; they are not a forecast. The percentage reduction is for modelled gas usage, not the whole energy bill.
Gas standing charges, installation, servicing, repair and finance costs are excluded from savings. Home sizes are illustrative, not Ofgem property classifications. Source: Ofgem energy price cap rates . Rate shown: October–December 2026.
Results are estimates based on current gas prices and your chosen settings. Future energy prices and actual savings may differ.
Could your savings make a new boiler worthwhile? TM Hughes offers free home surveys and no-obligation quotes for new Boiler installation across Essex.
Is Your Old Boiler Costing You More Than You Think?
Your boiler fires up every morning. Your radiators get hot. Nothing seems wrong.
But if your boiler is old and inefficient, you’re probably spending more on gas than you need.
Age alone doesn’t tell you how efficient your boiler is. Some older condensing boilers still perform well. Others waste far more fuel than modern models.
For example, a boiler operating at 65% efficiency loses 35% of the fuel’s energy. A modern boiler operating at 92% efficiency loses just 8%.
Signs your boiler may be costing you money include:
- Rising gas bills without a clear increase in usage
- Frequent breakdowns and growing repair costs
- An old, inefficient non-condensing boiler
- Poor heating controls or no room thermostat
- Heating or hot water which struggles to meet your needs
If your boiler wastes £200 in gas each year, that adds up to £1,000 over five years.
That’s £1,000 spent on wasted gas, assuming prices and usage stay the same. If gas prices rise over the next five years, wasted energy could cost even more.
That’s £ 1,000+ that could be spent on a new Boiler. The question is whether the savings justify the expense of a new Boiler.
How Much Could a New Boiler Save in Your Home?
A small flat will use less gas than a large detached house. But your boiler’s efficiency matters just as much as your home’s size.
The table below compares an old boiler operating at 65% efficiency with a new model operating at 92%.
| Property size | Annual gas use | Annual saving |
| Small 1–2 bedroom home | 6,000 kWh | £140 |
| Typical 3-bedroom home | 9,500 kWh | £222 |
| Large 4–5 bedroom home | 14,000 kWh | £327 |
We've based these savings on Ofgem's July 2026 gas usage figures for low, medium and high-use households. We've used these to represent different home sizes, with gas priced at 7.97p per kWh from October to December 2026. The figures assume your heating needs stay the same.
What could these savings mean for your home?
- Small homes: An inefficient boiler could be adding around £140 to your annual gas bill
- Three-bedroom homes: Replacing an old boiler could save around £222 a year
- Larger homes: Higher gas usage could mean savings of £327 a year or more
These figures assume your current boiler operates at 65% efficiency.
If your boiler operates at 85%, savings will be much smaller. A typical three-bedroom home would save around £58 a year.
Energy Saving Trust estimates savings of £420 a year when replacing a G-rated boiler without controls with an A-rated boiler and full heating controls.
This is the max possible saving, which includes improvements to heating controls, not just the boiler.
Is It Worth Replacing a Boiler Which Still Works?
A working boiler isn’t always an efficient boiler.
But replacing a boiler to save money on gas doesn’t always make financial sense.
The decision depends on your running costs, repair bills and what a new boiler would cost.
When Replacing Your Boiler Makes Sense
An old boiler can become expensive to keep, even while providing heating and hot water.
Replacement is worth exploring if:
- Your boiler is inefficient and uses too much gas
- Repairs are becoming more frequent or expensive
- Your heating or hot water keeps breaking down
- Replacement parts are difficult to find
- Your existing boiler no longer meets your needs
A new boiler could reduce fuel use and provide more reliable heating.
You’ll also receive a new manufacturer’s warranty.
When Keeping Your Boiler Could Be Better
Not every repair bill means you need a new boiler.
Spending £500 on a repair could make financial sense if your boiler is efficient and likely to last several more years.
Keeping your boiler may be the better choice when:
- You have a modern condensing boiler
- Annual servicing reveals no major problems
- Repair costs are non-existent or low
- Your heating and hot water meet your needs
Replacing your boiler may be the better option if it keeps breaking down, costs more to run and struggles to meet your heating and hot water needs.
At this point, it’s worth finding out how much a replacement would cost.
Then you can compare the price of a new boiler with the cost of keeping your old one running.
How Much Does a New Boiler Cost Compared With the Savings?
At TM Hughes & Son, new boilers start from £1,475.
The final price depends on your property, the boiler you choose, and your installation requirements.
Replacing an existing boiler in the same position will involve less work than changing boiler types or moving pipework.
But how do installation costs compare with potential savings?
Let's use a new boiler costing £2,000 as an example.
| Annual gas saving | Savings over 5 years | Savings over 10 years |
| £100 | £500 | £1,000 |
| £200 | £1,000 | £2,000 |
| £300 | £1,500 | £3,000 |
| £400 | £2,000 | £4,000 |
The table shows cumulative fuel savings before installation costs. Figures assume unchanged gas prices and usage. They are not forecasts of net financial savings.
For example, if installation costs £2,000 and you save £200 a year, your fuel savings would total £2,000 over ten years.
This doesn’t mean you’ve made £2,000. You’ve recovered the initial installation cost through reduced gas use, assuming prices and usage stay the same.
The comparison also excludes servicing, repairs and finance charges.
Before replacing your boiler, compare:
- The price of a new boiler
- Your estimated annual gas savings
- The cost of repairs your current boiler needs
- Any history of repeated breakdowns
- The warranty available with a replacement
- The total cost of any finance agreement
A single affordable repair may be the better option.
However, repeated repair bills and wasted gas can make keeping an old boiler more expensive than expected.
Maybe it’s time for a new Boiler.
Which New Boiler Will Save You the Most Money?
A combi boiler isn’t always cheaper to run than a system or regular boiler.
All three use modern condensing technology. The main difference is how each boiler supplies hot water.
Combi Boilers
Combi boilers provide heating and hot water without a separate storage cylinder.
- Suitable for small to medium-sized homes
- No hot-water cylinder
- Heating and hot water from one unit
System Boilers
System boilers use a separate cylinder to store hot water.
- Suitable for many family homes
- Can meet higher hot-water demand
- Work with pressurised cylinders
Regular Boilers
Regular boilers, also called heat-only boilers, often work with existing tanks and cylinders.
- Suitable for older systems and larger homes
- Good for supplying hot water to multiple outlets
- Offer high-efficiency heating
You don’t always need to convert your heating system to a combi boiler to save money.
TM Hughes installs all three types. Our free surveys will identify the right boiler type, size and setup for your home, heating and hot water usage.
How Can You Get the Most From Your New Boiler?
A new boiler is only part of an efficient heating system.
Modern controls and the right settings will help you use less gas without giving up comfort.
Ways to reduce wasted energy include:
- Room thermostats: Stop your heating once your home reaches the temperature you’ve set
- Heating schedules: Turn your heating on and off when needed, so you’re not heating an empty home
- Thermostatic radiator valves: Reduce heating in rooms you use less often, without turning down the whole house
- Boiler flow temperatures: Lower suitable flow temperatures to help your condensing boiler use less gas
- Zoned heating: Heat different areas of your home at different times, so you’re not wasting energy heating rooms you’re not using
- Smart heating controls: Control your heating from your phone, set schedules and adjust temperatures to avoid wasting gas
- Pipe and cylinder insulation: Keep hot water warmer for longer, so your boiler uses less energy replacing lost heat
- Annual servicing: Identify faults and issues which could affect your boiler’s efficiency and increase gas usage
Flow-temperature settings must suit your heating system. Always follow the manufacturer’s guidance, or have an experienced heating engineer set it up.
Is Your Old Boiler Worth Keeping or Replacing?
Your existing boiler may have years of useful life left. Or rising gas bills and repeated repairs may make replacement the better choice.
A Gas Safe registered engineer will visit your home to assess your heating needs and the work involved in fitting a new boiler.
During your survey, we’ll look at:
- Your home’s heating and hot-water requirements
- Your existing heating system and boiler
- Suitable combi, system or regular boiler options
- Heating controls options
- Installation work and system changes required
You’ll receive a free, no-obligation quote for the proposed installation.
You can then compare the cost with your existing boiler’s running costs, repair needs and potential savings.
Why Essex Homeowners Choose TM Hughes
When you’re spending money on a new boiler, you need confidence in the company fitting it.
TM Hughes has over 30 years of experience providing gas and heating services across Essex.
Our Gas Safe registered engineers install boilers in homes throughout Essex.
- Gas Safe registered heating engineers
- Over 30 years of Boiler installation experience
- Hundreds of 5-star Google reviews
- Free surveys and no-obligation quotes
- Installation prices from £1,475
- Up to 18-year warranties on selected boilers
- Boiler finance and optional service plans
Hi, I'm Terry, the founder and owner of TM Hughes & Son Gas Services
Please get in touch to book an appointment or receive a free, no-obligation quote
Call – 01245 830075
Email - info@tmhughesandson.uk
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