Boiler replacement. Made simple.

For a useful starting point, iHeat currently advertises the Alpha Etec NX from £2,145 and the Worcester Bosch Greenstar 4000 from £2,445, including installation and VAT. These are starting prices for eligible installations, rather than a price for every home.

The work involved also affects the cost. Replacing a combi boiler in the same position is usually simpler than converting a system with a hot water cylinder to a combi, which can involve removing the cylinder and altering pipework.

Compare the complete fitted package, including controls, system cleaning and warranty, rather than the boiler’s purchase price alone. See current iHeat boiler prices.

Repair is often worth considering when your boiler has been reliable, parts are available and the fault is inexpensive to fix. Replacement becomes more attractive when breakdowns keep happening or a major repair would mean spending heavily on a boiler with other ageing components.

For example, a £200 repair on an otherwise reliable six-year-old boiler is a different decision from a £700 repair on a 15-year-old boiler that has already broken down twice. These are illustrative repair quotes, but they show why age alone is not enough.

Ask the engineer what has failed, whether the rest of the boiler is in reasonable condition and what cover comes with the repair. Then compare that with a complete replacement and its warranty.

The best choice depends on how your household uses hot water, your water supply and the space available.

• Combi boiler: heats water on demand without a separate cylinder. It can suit a flat or a home where one shower is normally used at a time.
• System boiler: works with a hot water cylinder. It can suit a household that regularly needs hot water in several bathrooms at once, provided the cylinder and water supply are suitable.
• Regular boiler: works with a cylinder and usually loft tanks. Keeping this arrangement can make sense when replacing a boiler in an existing traditional system.

For example, two homes with three bedrooms may need different setups if one has a single bathroom and the other regularly runs two showers together. More about choosing a boiler type.

Boiler size refers to its heat output in kilowatts, or kW. There are two requirements to consider: heating your rooms and providing your hot water.

A combi may need a higher output for a shower than it needs to heat the house. That is why choosing purely by radiator count, or copying the number on your old boiler, can give the wrong answer.

For example, adding insulation can reduce your heating requirement, while adding a second shower changes your hot water needs. Buying a more powerful boiler will not, by itself, improve a restricted incoming water supply.

iHeat uses your home and hot water details to recommend models, with your quote checked by our in-house Gas Safe engineers. How we check boiler suitability.

Start with boilers that suit your home, then compare what you get for the complete installation price.

Useful differences include the warranty, hot water performance, cupboard fit, compatible controls and how well the boiler can reduce its output when your home needs less heat.

For example, a household with one bathroom may get little benefit from paying for substantially higher hot water output. A boiler that fits neatly into the available space and offers suitable controls may be more useful.

A longer warranty can also add value, but check its servicing requirements and what it covers. The most expensive boiler is not automatically the best match for your home.

The biggest efficiency improvement is generally when replacing an older, non-condensing boiler. Replacing a working modern condensing boiler may produce a much smaller saving.

As a simplified example, improving efficiency from 70% to 90% means using approximately 22% less gas to deliver the same amount of heat. If that heat previously cost £1,000 a year in gas, the equivalent cost would be around £778, a saving of about £222.

This calculation assumes unchanged heating demand and gas prices. It excludes standing charges and other gas use, and is not a guaranteed saving. Your actual result depends on the old boiler, installation, controls and how you heat your home. How boiler efficiency affects energy use.

Yes. iHeat offers monthly payment options, including 0% APR on selected packages.

For example, our published 0% APR illustration uses a £3,000 installation with a £750 deposit, followed by 24 monthly payments of £93.75. The total paid is £3,000.

The available terms depend on your chosen package. Compare the deposit, monthly payment and total amount payable together, because a smaller monthly payment can mean repaying over a longer period.

Finance is subject to status, affordability and lender approval. iHeat acts as a credit broker, not a lender. View finance options and terms.

Your confirmed quote covers your chosen boiler and the work agreed to install it, so you know the full price before fitting.

Our standard installation includes a chemical flush, and we remove the old boiler where it is safe to do so. Combi packages include a wireless thermostat, with options to upgrade or retain your existing control.

For example, when comparing two quotes, check whether both include the same thermostat, cleaning treatment and warranty. A lower headline price may describe a different package. Check installation inclusions.

Next-day installation is available for eligible orders, subject to availability. Book, pay and upload your photos before 3pm to qualify, with weekend exclusions applying. Available dates are shown when booking.

A straightforward combi replacement usually takes one day. Other installations typically take one to two days, while a conversion or relocation can take longer.

Heating and boiler-supplied hot water will be unavailable during the changeover. For example, replacing a combi in the same kitchen cupboard is usually quicker than moving it and removing an old cylinder. Check installation dates.

Not automatically. Radiators that are in good condition and adequately heat their rooms can often stay when the boiler is replaced.

Tell us about any existing problems before booking. For example, one room that never gets warm may need attention to its radiator, valve or balancing rather than a more powerful boiler. A leaking radiator also needs its own repair or replacement.

Checking these issues beforehand helps make sure the installation addresses the problems you actually want to solve.

Yes. You can request an engineer’s review before you book. On your quote results, open More details on a boiler and select Virtual Survey.

This is particularly useful if you are unsure whether to keep your existing boiler type, want to change its position or need help checking cupboard space and pipework.

Our engineers review your photos, and the team contacts you to help complete the booking once the proposed installation is approved. Requesting a virtual survey.

You receive the manufacturer’s boiler warranty shown with your chosen package, plus 12 months’ workmanship cover for the installation work we carry out.

These cover different things. An eligible fault with a component inside the boiler falls under the manufacturer’s terms. An issue with the workmanship on new pipework we installed falls under our installation cover.

Contact iHeat if you need help after fitting. Our aftercare team will help establish what is wrong and arrange the appropriate next step.

Arrange annual servicing in line with the manufacturer’s requirements and keep the service records to maintain your warranty cover. Read about warranty and aftercare.