Electric Boiler vs Gas Boiler: Pros, Cons & Running Costs
Deciding on the method of fuelling your central heating system depends on your property location, budget and needs.
Most homes run on gas-powered boiler systems when they are connected to the mains grid.
However if you live in a remote location or you’re not on the gas grid, you could consider using electricity to power your hot water.
In this article considering the advantages and disadvantages of both electric boilers and gas boilers, we examine:
- The top 10 HomeSage rated electric combi boilers
- The top 10 HomeSage rated gas combi boilers
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Top 10 HomeSage rated electric combi boilers
At time of writing, there are 4 manufacturers producing electric combi boilers with a choice of 41 models altogether.
The average price of an electric combi boiler is £1,692.
Here at HomeSage, we have developed our own unique scoring system to help you choose the most suitable boiler for your needs.
We rank boilers on:
- energy efficiency,
- price,
- length of warranty and
- amount of customer reviews and ratings on the Trustpilot website
Our ranking system gives you a concise understanding of different models at a glance.
The warranties available on electric boilers tend to be much lower than those of gas boilers with the exception of Heatrae Sadia who offer a generous 10-year guarantee.
Our rankings are biased against electric boilers purely because they are less environmentally efficient and cost more to run than gas-fuelled boilers hence their lower total scores.
Because of this, we’ve created an additional score which is in the ‘HS EXTRA SCORE’ column to give you a more comprehensive understanding of the boiler regardless of fuel methods.
The table below outlines the top 12 electric boilers available in the UK at time of writing:
| Make/Model Name | Band Rating | Parts and Labour Warranty | Output kW | Mounting | Price from | GENERAL HS SCORE | HS EXTRA SCORE |
| Electric Heating Company SlimJim Flow Boiler 4kw | D | 24 | 4 | Floor Standing | £665 | 57.46% | 79.00% |
| Electric Heating Company SlimJim Flow Boiler 7kw | D | 24 | 7 | Floor Standing | £690 | 57.40% | 78.67% |
| Heatrae Sadia Electromax 6kw Boiler | C | 120 | 6 | Floor Standing | £1,840 | 53.89% | 68.67% |
| Heatrae Sadia Electromax 9kw Boiler | C | 120 | 9 | Floor Standing | £1,960 | 53.59% | 67.11% |
| ELNUR Mattira 3kw Boiler | C | 24 | 3 | Wall Mounted | £2,325 | 46.03% | 62.35% |
| ELNUR Mattira 4kw Boiler | C | 24 | 4 | Wall Mounted | £2,325 | 46.03% | 62.35% |
| ELNUR Mattira 5kw Boiler | C | 24 | 5 | Wall Mounted | £2,325 | 46.03% | 62.35% |
| ELNUR Mattira 6kw Boiler | C | 24 | 6 | Wall Mounted | £2,325 | 46.03% | 62.35% |
| ELNUR Mattira 7kw Boiler | C | 24 | 7 | Wall Mounted | £2,325 | 46.03% | 62.35% |
| ELNUR Mattira 8kw Boiler | C | 24 | 8 | Wall Mounted | £2,325 | 46.03% | 62.35% |
| ELNUR Mattira 9kw Boiler | C | 24 | 9 | Wall Mounted | £2,325 | 46.03% | 62.35% |
| Electric Heating Company Comet Boiler 9kw | D | 24 | 9 | Floor Standing | £2,965 | 51.81% | 49.00% |
Top 10 HomeSage rated gas combi boilers
Gas combi boilers are the most cost effective and energy efficient style of boilers.
There are 206 available on the market currently produced by a range of manufacturers and with an average price tag of £1,098.
| Make and Model Name | Efficiency Rating | Parts and Labour Warranty | Output kW | Price from | TOTAL |
| Baxi Platinum 24 Boiler | 89.00% | 120 | 24 | £870 | 92.69% |
| Baxi EcoBlue Advance 24 Boiler | 89.10% | 120 | 24 | £945 | 92.51% |
| Baxi 636 Boiler | 89.00% | 84 | 36 | £975 | 92.43% |
| Baxi Platinum 28 Boiler | 89.00% | 120 | 28 | £1,005 | 92.36% |
| Baxi EcoBlue Advance 28 Boiler | 89.10% | 120 | 28 | £1,080 | 92.18% |
| Baxi Platinum 33 Boiler | 88.90% | 120 | 33 | £1,080 | 92.18% |
| Baxi EcoBlue Advance 33 Boiler | 89.10% | 120 | 33 | £1,175 | 91.94% |
| Worcester Bosch 2000 25 Boiler | 93.00% | 60 | 25 | £760 | 91.89% |
| Baxi EcoBlue Advance 40 Boiler | 89.10% | 120 | 40 | £1,235 | 91.80% |
| Worcester Bosch 2000 30 Boiler | 93.00% | 60 | 30 | £870 | 91.62% |
Electric boilers pros and cons
Advantages
- No gas required – there are currently over 2 million homes in the UK which do not have access to the mains gas network and therefore require an alternative fuel for their central heating.
- Don’t need as much servicing – they are cheaper to maintain and, if something does go wrong, replacement parts are also less expensive
- Compact – electric boilers are smaller and sleeker than other forms of boilers as well as being easily placed within your home.
- You can link it up to your solar panels – speak to your installer about installing or linking your electric boiler to your solar panels at an extra cost for maximum self-sufficiency possibilities.
- Very quiet – unlike other boilers which can disrupt your peace and quiet, electric boilers are virtually silent.
- Easier to install – they are one of the cheapest boilers to install as the process is very quick and straightforward.
Disadvantages
- Not ideal for larger homes – if you have higher hot water demands, electric boilers are fairly unsuitable for economic reasons as well as less capability to deal with the demand.
- Running costs – electricity is much more expensive than gas so even with a lower output boiler, your bill will still be higher.
- Loss of electricity – unlike gas boilers, electric boilers will cut out if there is a power cut which would leave you without hot water or heating until the electricity is back on again.
Gas boilers pros and cons
Advantages
- Cheaper fuel costs – gas is much less expensive than electricity so your bill will be lower for the same amount of heating or hot water.
- Able to meet higher hot water demands – unlike electricity, gas can handle higher demands for larger homes or if you need more hot water or heating at one time.
- Gas is always available – if you’re connected to the gas grid, it is highly unlikely that gas will not be available as there is always a running supply.
- Replacing gas boilers is simple – if you need to upgrade your boiler, getting a new one installed is a quick and simple process.
- More choice of models – because it is such a popular way to heat homes, there are a vast amount of different models available for every price point and requirement.
Disadvantages
- Requires regular services – to keep your gas boiler warranty valid, you must get it serviced every year to maintain it correctly.
- More components increase risk of faults – because they have a more complicated internal system than electrical boilers, there are more things that could potentially go wrong.
- Risk of chemical leaks – the biggest risk is carbon monoxide poisoning which is why you need to install and maintain gas boilers through a registered Gas Safe engineer.
- Take up more room – gas boilers can be cumbersome and require more careful placing when installing them as opposed to smaller electric boilers.
Output and how it differs for gas and electric combi boilers
Outputs needed for electric combi boilers
For every extra radiator in your property, you should add an extra 1.5kW of power to the output level of the boiler.
The output rate is the maximum amount used by the boiler to provide hot water.
This table is a guide to what size output your property may require:
| Radiators in your home | Minimum output rate recommended |
| 4 | 6 kW |
| 5 | 8 kW |
| 6 | 9 kW |
| 7 | 11 kW |
| 8 | 12 kW |
| 9 | 14 kW |
| 10 | 15 kW |
| 15 | 23 kW |
| 20 | 30 kW |
Small to medium sized properties have a good choice of models available if you require an electric boiler.
At time of writing, ACV is the only manufacturer producing electric boilers with outputs of 22kW, 28kW and 36kW combi and system boilers.
It is a general rule that electric boilers are unsuitable for larger homes where there is an increased and constant need for hot water or heating.
Outputs needs for gas combi boilers
There are a vast choice of outputs available in gas combi boilers and it’s important to get the right output level for your property.
A small property will require a gas combi boiler with an output of up to 27kW, a medium sized home would be 28kW to 34kW, whereas a large property requires an output level of 35kW+.
Running costs for gas and electric boilers
Electric boilers are much more expensive to run than gas, LPG or heating oil fuelled boilers however this cost is slightly offset by electric boilers requiring a lower output level.
To work out the cost of running a boiler, you measure the kW against the form of fuel.
For example, a standard gas boiler for a smaller home will run effectively with a 24kW boiler and it would cost 4p per unit of gas to work – meaning the sum is 24 x 4p = £0.96 per hour.
Electricity is more than double the price of gas at about 14p per unit so the sum for the same heater would be 24 x 14 = £3.36 per hour which is significantly higher.
However, it is important to note that an electric boiler with an output of 9kW would be suitable for the same size home so realistically would only cost £1.26 per hour which is considerably less.
£1.26 is clearly lower than £3.36 but it’s also substantially more than the 96p cost per hour of a gas boiler – 31.25% more in total.
How efficient are electric boilers?
Energy efficiency refers to how much energy it takes for the boiler to heat up your hot water and is measured in percentage format.
If a gas combi boiler has an efficiency rate of 94%, that is how much it uses to heat the water whereas it will take 6% on internal operations as a boiler system and technically that energy is classed as ‘lost’.
Electric boilers are usually almost 100% energy efficient.
However, this is slightly misleading as the production and delivery of electricity to your property results in far more CO2 emissions than gas fuels so it isn’t as environmentally friendly overall.
Energy related Products Directive (ErP) is therefore calculated to give a more realistic energy efficiency rating to include that factor and as you can see from the table below, results in electric boilers being far less energy efficient.
| Fuel | Emissions kgCO2 per kWh | Fuel Factor | Multiple of gas emissions |
| Mains Gas | 0.216 | 1.00 | 1.00x |
| Electricity | 0.519 | 1.55 | 2.40x |
| LPG | 0.241 | 1.06 | 1.12x |
| Heating oil | 0.298 | 1.17 | 1.38x |
Electricity versus gas combi boilers – which is the cheapest?
Although electric boilers cost more to run annually, there are some benefits to choosing this option which could save you money.
It’s important to consider the savings you might make elsewhere if you opt for a boiler fuelled by electricity, such as:
- Installation costs
- Running costs
- Price of the boiler
- Cost of annual service
Cost of the boiler itself
This can vary greatly depending on the manufacturer, model and output you decide to go for.
Installation
We always recommend getting multiple quotes for boiler installations as they can vary so dramatically from firm to firm, and also depend on the amount of work needed to be done to prepare your property.
Because electric boilers don’t require a flue, condensate pipe or gas line connections, they are generally quick and easy to install but you can still expect to pay anywhere from £500 to £2,000 for supply and installation.
Running costs
As previously discussed, electricity costs more per unit than natural gas and if you were running an electric boiler of 12kW for 70 hours per month, annually this would cost £1,451.52.
Heating the same property for the same amount of time with a 24kW combi gas boiler with gas costing 3.8p/kWh results in an annual cost of £766 which is about half the cost.
It’s worth noting that gas boilers do require a small amount of electricity to run, for components such as the fan and digital display panel so that cost also needs to be factored in.
Servicing
For your peace of mind and to maintain a valid warranty, you need to service your gas boiler annually by a Gas Safe registered engineer.
However, electric boilers don’t need the same amount of servicing though it is recommended just for your safety.
A gas boiler service should take at least 30 minutes and could cost you between £50 to £160 a time.
This adds to the cost of your boiler over all – if you had a £100 service each year for 10 years, that’s an extra £1,000 to consider.
Repairs
Because electric boilers don’t have any internal moving components which may break or become faulty, it’s much less likely they will need repairing.
If your gas combi boiler needs repairing, you can expect to pay anything from £150 to £400 depending on the seriousness of the issue.
There is no guarantee that you will need to repair your boiler during its lifetime so we haven’t added that into the equation but it is something to be aware of.
Get advice from an experienced installer
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You could save up to 54% of the cost of the supply and the installation of your new boiler by leaving your details with us on our online form.
Simply fill in your information, and we then contact three or four local, trusted and Gas Safe regulated engineers with your details.
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