The Pros and Cons of Combi Boilers


Combination boilers (also known as "combi boilers") have become more and more popular in the UK over the past few years, with over 70% of homes choosing to install a combi boiler, over regular hot water or system boilers.  

What is a Combi Boiler?


The pros and cons of combi boilers

Combi boilers are essentially high efficiency water heater and central heating units, which means that they can heat your home and provide hot water, without the need for a separate water tank. They tend to be more compact than other central heating systems, as they combine these two household functions into one appliance (hence the name "combi boiler").

Who Should Use a Combi Boiler?

Due to their small size and ability to heat water on demand, combi boilers are most suited to homes with limited space, or for couples or small families. It is possible to purchase an oil-fired combi boiler, however, gas and LPG models are more common.

The Pros and Cons of Combi Boilers

If you are considering replacing your current boiler with a combi boiler, or moving into a house with one, it is important to know the pros and cons of these systems.


Pros: The Benefits of a Combi Boiler

There are a number of great features that have made combi boilers the most popular boiler type across the UK. In general, combi boilers are:


Combi boilers are more efficientMore Efficient

Combi boilers are highly efficient when compared to older boiler models. In fact, replacing your boiler with a newer combi boiler could help you to save up to £300 a year on your heating bills.  

Combi boilers are cheaperCheaper

Combi boilers are far less complex than traditional heating systems, which means that installations tend to be cheaper. It is also easier to find replacement parts if a problem occurs.

Combi boilers are fasterFaster

With no water tank to heat up, combi boilers can provide an unlimited supply of hot water on demand. No waiting time!

Combi boilers are more compactMore Compact

As there is no need for a separate water tank, combi boiler systems take up much less space than conventional heating systems. This makes them ideal for homes that have limited room.

Combi boilers are saferSafer

The cold water from a combi boiler system is always safe to drink as it is fed directly from the mains. However, this is not always true of traditional systems, which may store cold water in a tank before it is piped through the house.

Combi boilers are easier to sellEasier to Sell

As combi boilers tend to be more efficient than other boiler types, this can be a selling point if you are looking to rent or sell your property. This will also show on the Energy Performance Certificate (EPC).

Combi boilers are less likely to malfunctionLess Likely to Suffer from Pressure Issues

Combi boiler systems do not tend to suffer from air locks or low pressure, as the hot water is taken directly from the water mains.

Combi boilers are cleanerCleaner

Central heating systems with a combi boiler generally have less sludge build up, because the water is piped directly from the mains and not kept in a tank where it can accrue rust and debris.

Combi boilers are easier to serviceEasier to Service

The popularity of combi boilers means that a majority of boiler engineers are trained how to repair and service them. This makes it easier to find qualified engineers in your area.


Find Boiler Engineers in Your Area 

Cons: The Disadvantages of a Combi Boiler

Despite the popularity of combi boilers, there are several issues that you should bear in mind when considering replacing your boiler.

The disadvantages of combi boilers include:


Combi boilers depend on mains pressureDependence on Mains Pressure

To ensure that your combi boiler is working properly, you need good mains pressure. If you are having a new boiler fitted, you should check what the mains pressure in your area is before you go ahead with the installation.

Combi boilers have limited useLimited Use

With a combi boiler it is not possible to run more than one shower or bath at a time, or to turn on the hot tap while showering. This may be an issue if you live in a large house with a number of bathrooms and en suites, or with lots of people.

Combi boilers do not use an immersion heaterNo Immersion Heater

As there is no water tank, if your combi boiler breaks down then you will be left without hot water as well as central heating (unless you install an electric shower).

Combi boilers do not work with a power showerNo Power Shower

You can't have a power shower with a combi boiler, as the water pressure is set by the pressure level at the water mains.


Need a Combi Boiler Service or Repair?

If you are experiencing issues with your combi boiler, need to book a service or want to know how much an installation will cost, simply click below to view instant, online quotes from reliable, Gas Safe registered engineers in your local area now!


find local engineers now!  


Want to Learn More?

If you have further questions about combi boilers, check out our Combi Boiler Servicing page or read our top tips for Boiler Replacements.


Need some help?

Have you visited our Help and Advice pages?

Alternatively, fill out our
contact form click here.

Call us FREE on
0800 080 7875

Customer testimonials
Customer testimonials

Need some help?

Call us FREE on 0800 080 7875

Have you visited our Help and Advice pages?

Alternatively, to fill out our contact form click here.

Reg. office: Suite 1 Clare Hall, St. Ives Business Park, Parsons Green, St. Ives, Cambs PE27 4WY.

Registered in England & Wales no. 7814907.

© 2021 MyBoilerService Ltd. E&OE. All rights reserved.