Back Boiler Service: Costs, Process & Booking

jamie robinson
Written by Jamie Robinson
Updated on 23rd May 2024
Posted on 23rd May 2024
Topic: Boiler Advice

Back boilers are an older type of central heating system that held popularity in the 70s and 80s.

They consist of a hot water tank behind a gas fire or an open fireplace for heating and hot water.

gas safe logo

They have since become have been quickly outdated and illegal to newly install in the UK (2005) due to energy efficiency concerns, particularly compared to modern combi boilers and system boilers.

Back boilers have quickly been replaced in most homes by new condensing boilers because they are less efficient, unsafe, and expensive to run and maintain.

But for the minority that may still have an old back boiler in their home, we will dive into the servicing side of back boilers and its importance in this guide from Boiler Central.

Want to upgrade to a new boiler? Get a fixed price boiler quote online now in 20 seconds

Get an online fixed price in 20 seconds:

What kind of fuel does your boiler use?

What does a back boiler service include?

For a back boiler service, the engineer is essentially servicing two gas appliances, the boiler as well as the Gas fire. The service usually includes :

  • Removal and cleaning of the fire
  • Removing the burner and dismantling
  • Cleaning in and around the back boiler 
  • Safety operations checks
  • A visual inspection
  • A report that meets UK regulations
  • Flue integrity test

How often should I service my back boiler?

Back boilers should be serviced the same amount as any other boiler. It is recommended to get your boiler serviced at least once a year.

 An annual boiler service will help give you peace of mind that your heating system works efficiently, functions correctly, and has no water or gas leaks, preparing you for the long winter ahead. 

An annual boiler service can also help extend the lifespan of your boiler and save you a lot of money in repair costs further down the line.

If a back boiler isn’t serviced regularly, then it can begin to produce carbon monoxide. A carbon monoxide alarm is very important to ensure your safety when owning a back boiler.

Who can service a back boiler?

You will need a Gas Safe registered engineer for a back boiler service. Getting your back boiler serviced may be more difficult to get hold of than your usual combi or system boiler service.

 Many younger plumbers may have not dealt with back boilers, or taken them apart before, therefore a handful of engineers don’t service back boilers and have a lack of experience in doing so.

 Nowadays, there are fewer back boilers in the UK, so finding a qualified engineer to service your back boiler can sometimes be a challenge.  

Landlord back boiler service

A landlord is required to gain a Gas Safety certificate every year, to make sure the boiler is working safely and efficiently to give peace of mind to their tenants. This is no different in the case of back boilers. 

Once a Gas Safe registered engineer has completed the back boiler service, the landlord can be given a Gas Safe certificate to keep up with regulations.

How long should a back boiler service take?

A back boiler service should take around 1-2 hours to complete depending on things like its condition and accessibility for the engineer. 

Back boiler servicing usually takes longer because they are usually situated behind fireplaces or within cabinets, making access for servicing more challenging. 

Engineers may need to remove panels or dismantle parts of the fireplace to reach the boiler, adding to the overall boiler servicing time.

Also, back boilers are often connected to hot water cylinders, which also need to be checked during the servicing process. This involves testing the pressure, temperature, and overall performance of the hot water system, adding extra time to the service.

Back boiler service cost

The back boiler service cost will be between £80 and £160, depending on location.

Their more expensive cost ultimately boils down to their difficult access points, It is also more complicated due to the engineer servicing both gas appliances such as the boiler, and the gas fire.

A traditional combi or system boiler service is easier to access and more straightforward.

Boiler TypeService Cost
Back Boiler£80 to £160
Gas Boiler£60 to £120
Oil Boiler£75 to £150
Electric Boiler£55 to £105

Get an online fixed price in 20 seconds:

What kind of fuel does your boiler use?

Back boiler service benefits vs negatives

Back boiler replacement

Whether your old, trusty back boiler has finally packed in after all those years, or its safety and efficiency concerns are getting the better of you, replacing a back boiler can seem like a challenging task.

 While the back boiler replacement process may require some investment upfront, the benefits include improved energy efficiency, reduced heating costs, and much more reliability.

 Also, modern boilers such as a combi boiler offer advanced features such as digital controls and compatibility with renewable energy technologies, providing you  with greater control and flexibility over their heating system

  • Assess the existing back boiler and surrounding components.
  • Shut off gas and water supply.
  • Remove the back boiler unit.
  • Prepare the location for the new boiler installation.
  • Install new boiler unit securely.
  • Connect the new boiler to existing pipework and supplies.
  • Install necessary flue components and ensure ventilation.
  • Commission the boiler and adjust the settings.
  • Complete necessary documentation and certification.

Back boiler replacement cost

Replacing a back boiler in the UK can cost anywhere between £3200 to £4700 for the full replacement.

The cost is affected by the type and size of the boiler, for example, if you have a larger property and need a more powerful boiler, the replacement cost may be on the higher end.

Although the upfront cost of replacing a back boiler may seem high, it is more than worth it on the other end when it comes to saving money on energy bills. A combi boiler’s efficiency ranges from 90-98% whereas a back boiler can only go from around 80%.

Are there any government incentives for back boiler replacement?

A grant means the government will pay all the cost of upgrading your back boiler to an A-rated combi boiler. 

In the UK, back boiler replacement grants are offered through the government’s ECO4 scheme, aimed at assisting low-income homeowners or tenants receiving benefits, enabling them to upgrade their outdated back boilers.

How do back boilers work?


Back boilers receive cold water through an inlet at the bottom. Hot gases traveling through the flue heat the heat exchanger positioned at the end of the combustion chamber. It then warms the cold water, which is delivered to the output via an electric pump.

Boiler service plan 

A boiler service plan is an option that allows you to spread the cost of a boiler service monthly, instead of paying the full amount at once.

So you can get your yearly service, with reminders for your back boiler. This ensures that any problems can be addressed as quickly as possible so they don’t worsen over time.

Get an online fixed price in 20 seconds:

What kind of fuel does your boiler use?

FAQ’S

What safety measures can be taken to prevent carbon monoxide risks between back boiler servicing?

You can install carbon monoxide detectors throughout your home to prevent carbon monoxide risks between back boiler servicing.

Additionally, ensuring proper ventilation and airflow around the back boiler area, as well as promptly addressing any unusual odors or symptoms, can help mitigate potential risks.

Are there different options for servicing a back boiler if finding an engineer is difficult?

If finding an engineer experienced with back boilers proves challenging, it may be worth exploring options such as contacting boiler manufacturers for recommendations or reaching out to local trade organisations.

Can I get a back boiler service near me?

Yes, you can get a back boiler service near you by searching online for local boiler service companies.

The cost of back boiler service may differ depending on your location, but you can contact the manufacturer of your boiler for suggestions. Also, make sure the engineer is Gas Safe registered and has experience with back boilers.

Written by
jamie robinson
Jamie Robinson Home Improvement Expert
Posted on: 23rd May 2024
Topic: Boiler Advice

Jamie Robinson is our resident Home Improvement Expert at Boiler Central, specialising in energy-efficient heating solutions. His expertise lies in guiding customers to select the ideal boiler for their unique home needs, focusing on functionality and environmental sustainability. With a commitment to staying updated on the latest industry advancements, his goal is to enhance home heating efficiency and contribute to a more sustainable future.

Book your boiler service today!

Keep your warranty intact and increase the lifespan of your boiler

Get my fixed price
Get a great price on a Which? Best Buy boiler online in 20 seconds
  • Over 15,000 boiler installed
  • Rated Excellent on Trustpilot
  • Fair, fixed and final prices
  • No pushy salespeople
  • Next-day installation
  • 0% deposit interest-free finance
Next-day fitting available until 2pmGet a quote now >