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Back Boiler Replacement - Quotes & Prices

Old Back Boiler vs New Combi Boiler
Old Back Boiler vs New Combi Boiler
Back boilers are, to put it frankly, relics from the 1960s, 70s and 80s. They sit behind a gas fire or stove, tucked away in the wall, providing heating and hot water for the home.

Back boilers are no longer being manufactured and are being replaced by modern units that are more efficient, compact and safer. If your property has a back boiler that’s either given up or you simply want a more modern heating system, most professionals will advise you to move on to a combi boiler.

Replace your back boiler with a combi

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What is a back boiler?

A back boiler fits in the recess behind a fireplace or gas fire. It uses the heat generated to produce hot water for central heating and domestic use throughout the home. The boiler itself is hidden behind the fireplace but needs a separate water tank and hot water cylinder to be stored somewhere else in the home.

In the 1960s, 70s and 80s a back boiler was the best choice for many homes when compared to the traditional floor standing boilers that were roughly the size of a washing machine! At the time a back boiler was the cheaper option to install and was more energy efficient.

The back boiler relies on a very simple system with few components when compared to modern boiler technology and, as a result, has a reputation for reliability and endurance with many still operating today. It can also improve the energy efficiency of the fire or stove it is attached to. If a back boiler is still operating safely, it is possible to maintain it with regular servicing and avoid the cost of changing to a modern combi system.

However, you also need to consider that sticking with a back boiler is less energy efficient and will cost more in energy bills.

Why aren’t back boilers available today?

As with all technology, central heating systems have moved on since the back boiler's heyday.

In 2005, in an effort to improve both boiler safety and the UK's energy efficiency, the government introduced new regulations. From that point all boiler installations – replacements and new builds – had to be condensing models.

While its only competition used to be huge floor standing units (roughly the size of 2 washing machines), the back boiler is now overshadowed by modern condensing combi boilers which are compact, safer and more efficient.

Homes with back boilers often also have rather unattractive gas fire fronts that aren't so popular with those of us concerned with interior design. The changeover to a combi boiler can mean the opportunity to rid your home of an eyesore you've been putting up with for years.

When it comes to repairing an old back boiler, spare parts are incredibly difficult to come across, if they’re available at all, so you will need to switch to a combi or other more modern boiler type.


Dangers of a disused back boiler

A disused back boiler can be a real danger in your home. Even if the boiler is empty it will retain residual moisture and if the fuel burner in front of it is still in use, it will heat the boiler and create steam. If the boiler is not in an open vented condition (i.e. sealed) internal pressure will build which can result in an explosion. Over the years incidents like this have caused several serious injuries and even one fatality.

Additional risks associated with disused back boilers include the corrosion and fracturing of old pipework which could pass harmful gases into other areas of the home or the pipework reaching such a high temperature that it creates a fire hazard. Also, as the back boiler sits within the home's wall the continual expanding and contracting of the old boiler casing under high temperatures may cause structural damage to the home.

If you have a disused back boiler in your home we strongly recommend that you seek professional advice about protecting your home and removing the boiler.

Replace your back boiler with a combi

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What is a combi boiler?

A combi boiler, short for combination boiler, is the most compact boiler on the market as all the elements are contained within a single unit. There is no need for a water tank or storage cylinder as, rather than keeping a store of hot water, the combi heats water on demand. They take up very little space in the home and are usually mounted on a wall in the kitchen or utility room.

They are the most popular type of boiler in the UK and, as they don't expend energy keeping surplus hot water, they are the most energy efficient. The only potential drawback to a combi is that it relies on the mains pressure for water flow. For homes with a weak mains pressure this can present a problem, but it is possible to fit a pump to improve this.

Combi boiler benefits

Back boilers are outdated heating systems that are expensive to run as they’re much less energy efficient.

The most popular solution is to replace a back boiler with a combi boiler. There are many benefits to installing a combi as it is:

Energy efficient: typically, a back boiler provides only 78% energy efficiency which is below the government's minimum requirement of 86%. Many modern boilers can achieve efficiency of 90% and more.

Cheaper to run: the energy wasted by a back boiler is costing you money. Replacing with a modern boiler with a higher efficiency rating could save you up to £320 a year.

Safer: an unused and empty back boiler can be dangerous as, if heated, pressure can build inside causing an explosion.

Cheaper and simpler to install: generally speaking, combi boilers are the cheapest boiler type to install as they don’t require any tanks or cylinders.

More compact: a back boiler requires 2tanks to be kept somewhere in your home whereas a combi boiler is a single cost-effective wall-mounted unit.


How much could a combi boiler save me?

The biggest reason why most homeowners choose to have their back boiler replaced is to reduce their energy bills.

Replacing your back boiler with a modern combi boiler could reduce your heating bills by as much as £305 each year* – the exact amount you’ll save will depend on the efficiency of your back boiler, your energy tariff and how well insulated your property is.

Get free back boiler replacement quotes

At Boiler Guide we have a network of heating engineers right across the UK who can replace your old back boiler with a modern combi boiler. By taking a few moments to complete our simple online form, you can get free boiler replacement quotes from up to 3 local heating engineers.

Replace Your Back Boiler With a combi

Get free quotes from trusted engineers in your area today.



Boiler Guide Team

About the author

Boiler Guide Team

Boiler Guide has been home to a host of heating experts who have helped millions of UK homeowners searching for advice and guidance. If you've got heating questions, we'll have the answers.

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