If your boiler is getting old, unreliable or expensive to repair, replacing it with another gas boiler can feel like the obvious next step. It is familiar. It works with your radiators. And when you just want your home to stay warm, choosing what you already know can feel like the safest, easiest option.
But your next boiler does not have to be gas in order for you to achieve all these things.
Before you commit to another fossil fuel boiler, our free Cost & Carbon Calculator helps you see how your currency heating could compare with our heat battery boiler – a better boiler powered by smart electricity.
In just a few clicks, you can estimate running costs, carbon savings and what switching away from gas, oil or LPG could look like for your home.
Quick answer: what does the Cost & Carbon Calculator do?
Our free Cost & Carbon Calculator helps you compare your current boiler with the ZEB heat battery boiler.
Simply input what you currently use for heating, such as gas, oil, LPG or direct electric, choose a flexible electricity tariff, and add your estimated annual energy usage. The calculator then shows estimated annual running costs and carbon savings, so you can see how switching to a heat battery boiler could compare before taking the next step.
It is not a quote or a final assessment, but it gives you a helpful starting point when deciding what to do about your old boiler.
Why use the calculator before replacing a boiler?
Most people only think seriously about their boiler when something changes. Maybe yours is getting noisier. Maybe it needs another repair. Maybe you are planning ahead before winter. Or maybe you know you want to move away from gas, but you are not sure what the alternative would actually cost.
That is exactly what the calculator is designed to help with.
It gives you a simple way to compare your current heating with a ZEB, using information that is relevant to your home. Instead of guessing, you can see an estimate of:
- How your annual running costs could compare
- How much carbon you could save
- How different tariffs affect the numbers
- Whether it is worth taking the next step with a home check
For many homeowners, that is the first moment switching stars to feel practical.
Understanding the heat battery boiler that stores heat from electricity
The tepeo ZEB heat battery boiler is designed for suitable homes that want familiar central heating without oil, gas or LPG. It connects to radiators or underfloor heating, fits indoors with no outdoor unit and stores electricity as heat so your home can stay warm when you need it.
So instead of asking you to completely rethink your heating, the ZEB gives suitable homes a smarter way to replace an old boiler.
It is not a heat pump. It is not a standard electric boiler. It is a heat battery boiler: designed to charge like a battery and heat like a boiler.
Could the ZEB cost less to run than your old boiler?
This is one of the biggest questions people ask when they are thinking about switching from gas, oil or LPG. The honest answer is: it depends on your home.
Your running costs will be affected by your heat demand, insulation, heating habits, hot water setup and electricity tariff. But the important thing to know is that the ZEB does not work like a standard direct electric boiler.
A standard electric boiler usually uses electricity at the exact time your heating is on. That can mean using electricity during more expensive peak periods.
The ZEB is different because it stores electricity as heat. It charges during cheaper off-peak windows, then uses that stored heat later to warm your home through your radiators or underfloor heating. That smart charging is what helps the ZEB make use of flexible electricity tariffs.
The calculator helps you see what that could mean for your home.
How much carbon could you save by switching?
If your current boiler burns gas, oil or LPG, it creates emissions every time it heats your home.
The ZEB does not burn fossil fuels in your home. It uses electricity, stores it as heat, and releases that heat through your central heating system when needed. That means switching from a fossil fuel boiler to a ZEB will significantly reduce your home heating carbon emissions.
Even switching from an electric boiler to a heat battery boiler will save you carbon, because your ZEB charges at cheaper times of day, when more electricity is generated by renewables. You can read more about the comparison with direct electric boilers on our blog here.
The calculator shows estimated carbon savings based on your current heating fuel and usage. It also helps make those savings easier to understand with everyday comparisons, so you are not just looking at a number in kilograms.
For homeowners who want their next boiler decision to be a more climate-conscious one, this can be a useful way to see the impact clearly.
Switching from gas, oil, LPG or direct electric
The calculator is especially useful if you are currently heating your home with fossil fuels.
If you use gas
You may be wondering whether replacing your gas boiler with another gas boiler is still the simplest choice. The calculator helps you compare that familiar route with a ZEB, so you can see whether switching could make sense for your home.
If you use oil
Oil heating can be expensive and carbon intensive. If you are looking for a cleaner alternative that does not rely on fuel deliveries, the calculator can help you understand how the ZEB could compare.
If you use LPG
LPG homeowners often have fewer heating options than mains gas customers. Running costs can fluctuate, fuel deliveries need to be planned, and storage tanks can take up valuable space outside the home.
If you use direct electric
Direct electric heating can be simple, but it can also be expensive to run, especially if you are using electricity at peak times.
Why your electricity tariff matters
The ZEB is designed to work with smart, flexible electricity tariffs.
These tariffs offer cheaper electricity at certain times of day, often overnight or during off-peak periods. The ZEB can use those windows to charge its heat battery, storing heat ready for when your home needs it.
That is why the calculator asks you to choose a tariff.
Your tariff can make a real difference to estimated running costs. A suitable off-peak tariff can help the ZEB charge when electricity is lower cost, rather than relying on peak-time electricity whenever the heating comes on.
In simple terms: the ZEB is not just electric heating. It is smart electric heating with storage built in.
Is the calculator a quote?
No. The Cost & Carbon Calculator is not a quote, guarantee or final suitability assessment. It is an estimate based on the information you provide and the assumptions used in the tool.
Your actual running costs will depend on factors such as:
- your home’s heat demand
- insulation and property type
- how you use your heating
- your hot water setup
- your electricity tariff
- future energy prices
- weather conditions
- installation design
That is why we use the calculator as a helpful first step.
If the results look promising, the next step is to complete a home check. Our team can then look at your property in more detail and help you understand whether the ZEB could be suitable.
When should you use the calculator?
The Cost & Carbon Calculator is useful if you are:
- thinking about replacing an old gas boiler
- deciding whether to choose another gas boiler
- using oil or LPG and looking for an alternative
- looking to save money by switching from your expensive electric boiler
- comparing running costs before switching
- trying to reduce your home’s carbon footprint
- interested in smart tariffs
- looking for a heat pump alternative
- wondering whether the ZEB could work for your home
It is also a good place to start if you are not ready to speak to anyone yet, but want to explore your options in your own time.
What happens after you use the calculator?
Once you have seen your estimated results, you can decide whether to take the next step.
If the ZEB looks like it could be a good fit, you can complete our home check which will tell you if your home is suitable and give you the option to book a call with a member of our team to talk about your requirements further.
From there, our friendly team can talk you through:
- whether your home is likely to be suitable
- where the ZEB could be installed
- how it would work with your radiators or underfloor heating
- what hot water setup you may need
- what installation could involve
- whether you could benefit from the £2,500 tepeo Early Grant Match
You can also download our Better Boiler Guide if you want to compare your options in more detail before deciding.
Try the free Cost & Carbon Calculator
Your old boiler may be ready for retirement. But that does not mean your next one has to be gas. Before you choose another fossil fuel boiler, take a few minutes to compare the cost and carbon of switching.
Our free Cost & Carbon Calculator gives you a simple way to see how your current heating could compare with the tepeo ZEB heat battery boiler. It is quick, clear and designed to help you make a more informed decision about your next boiler.
Cost & Carbon Calculator
Compare the annual running costs and carbon emissions of your current boiler with a tepeo heat battery boiler upgrade by using this simple tool
Your Inputs
Annual Running Cost Estimate
Carbon Saving
By switching to a tepeo boiler, you could save: