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Should I replace my old back boiler with a combi boiler?

Back boilers are a rather old-fashioned method of heating. They are expensive to maintain and operate as well as be less efficient than modern boilers. If you’re currently using an old boiler in your home, look into a back boiler replacement, changing it to a more modern and efficient model, like the combi boiler.

Is a boiler a “back?

Back boilers are heating device that is installed to the back of your fireplace. An outdated method of heating back boilers, these systems were utilized to supply hot and heating water.

If you’re currently using an old boiler in your home, it’s most likely to be one of the Baxi Bermuda back boiler, an extremely popular model in the past times. While these models were popular during earlier times however, they began to fall out by the time different boiler models being created.

Here’s a list of advantages and disadvantages for back boilers.


Popular in the 1960s
Constructed with fewer parts
The possibility of hiding it from view behind an open fireplace.


A dated method of heating
Not as efficient in energy efficiency when compared to other types of boilers (estimated to be less than 80 percent)
No longer installed
Parts for spares are extremely difficult to locate.

When you look at the list above, it is concluded that the cons outweigh the advantages with regard to back boilers. Combi boilers, heat-only and system are the most popular boiler types that are used in the UK and combi boilers are the most well-known.

What is a combi boiler?

Also known as combination boilers combi boilers can provide hot and heating within one unit. There are no additional tanks or tanks are needed and they take up little space. Combi boilers also condensate this means they are able to recycle and recover latent heat by utilizing condensation of water vapour, thus making them energy-efficient.

Here’s a list of advantages and disadvantages of combi boilers:


Space saving They can be incorporated into standard kitchen cabinets
It is estimated that most combi boilers boast the efficiency of more than 90 percent.
On-demand hot-water
There is no water tank or cylinder that is required , which makes water safer and cleaner to use.
Installation is likely to be less expensive and more efficient because there are fewer components
The new combi boilers have condensing.
Part L in the regulations for building requires that every new combi boiler is equipped with an additional energy-efficient measure like smart thermostats
The replacement of your old back boiler with a energy-efficient, A-rated combi boiler could let you save as much as PS200 on your cost of energy*.


No backup immersion heater
Pressure can drop in water in the event that more than one appliance needs hot water simultaneously
The system won’t provide hot water to the radiators or taps at the same time.

Cost of replacing the back boiler

It is likely that the removal of your back boiler will require a lot of digging up since it’s placed behind the fireplace. The process typically includes:

The fireplace must be removed
Removal of the back boiler system
Mantle Space Reconstruction
Installing the combi boiler at another area
New pipework is installed to go with a new combi boiler
It is necessary to work to the chimney system in order to fit to the boiler combi (the Back boiler has been using it’s chimney).

The replacement of your backup boiler by a new combi boiler will likely be costly that is estimated to cost anywhere from PS3000 upwards. While this might appear to be an expensive cost, keep in mind the opportunities to save money using a new, efficient combi boiler. In addition, you can benefit from the high quality of the heating as well as hot water which combi boilers can provide.