How Long Does It Take To Fit a Boiler?

It depends on the circumstances of the job. Some boiler fitting jobs take only a few hours, while some could take up to three days.

All boiler fitting jobs fall into four categories: fresh installation, like-for-like replacement, boiler upgrade (aka system change) and boiler relocation. The table below shows how long it takes to fit boilers in each category.

How Long Does It Take To Fit a Boiler?

Boiler fitting job type	How long does it take to fit the boiler
Fresh installation	1-2 days
Like-for-like boiler replacement	4-6 hours
Boiler upgrade or system change	1-3 days
Boiler relocation	2-3 days

Don’t worry if you don’t understand what these four categories mean. We will explain them. We will also discuss factors and additional tasks that influence how long it takes to fit boilers.

Fresh Installation

Boiler type	How long does it take to fit the boiler
Combi boiler	1-2 days
System boiler	1-2 days
Regular boiler	1-2 days

With fresh installation, this is the first time installing a boiler on the property. You are starting with the clean state. The framework the boiler needs to function isn’t already in place. Therefore, your installer has to set that up too.

This framework includes flues, pipes, thermostats, electricity lines and water tanks. Fitting the boiler and its framework will take a minimum of 1-2 days. That’s how long it takes to fit a boiler (combi, system or regular) in this situation. 

Like-For-Like Replacement

Boiler replacement job type	How long does it take to fit the boiler
Combi boiler for combi boiler swap	4-6 hours
System boiler for system boiler swap	4-6 hours
Regular boiler for regular boiler swap	4-6 hours

The boiler’s framework is already in place. It is also likely compatible with the new boiler. Therefore, the installer only has to remove the old boiler and install the new one. Because of this, boiler fitting jobs in this category don’t take as long as the others. 

It should be over within a few hours, even if the existing boiler framework needs modification. Like-for-like boiler replacement also doesn’t require specialised skill. However, we recommend hiring Gas Safe registered engineers for even the most basic boiler fitting jobs.

Boiler Upgrading Or System Change

Types of Boiler upgrade or system change jobs	How long does it take to fit the boiler
Regular boiler to combi boiler	1-2 days
Regular boiler to combi boiler	1-2 days
System boiler to combi boiler	1-2 days
Combi boiler to system boiler	1-2 days

Boiler fitting jobs in this category are about installing a new system. Therefore, the framework of the old boiler might not be compatible with the new one. For example, regular and system boilers need water tanks, while combi boilers don’t. In other words, these boilers use different frameworks. 

So, upgrading or changing a boiler system is like a fresh installation. The only difference is the additional task of removing the oil boiler and its framework. However, you don’t always have to remove the entire framework. Sometimes, only mild modification is required. 

For example, boiler systems older than 15 years usually have 15mm pipes for gas supply. This is against modern Gas Safe regulations, which require combi boilers to use 22mm pipes.

There are several reasons to upgrade or change your boiler system. For example, combi boilers are low-maintenance and space-efficient, while system boilers are better for large properties with many rooms.  

Boiler Relocation

Boiler fitting and relocation job type	How long does it take to fit the boiler
System boiler to system boiler swap with relocation	2-3 days
Regular boiler to regular boiler swap with relocation	2-3 days
Combi boiler to combi boiler swap with relocation	2-3 days
Regular boiler to combi boiler upgrade with relocation	2-3 days
Regular boiler to system boiler upgrade with relocation	2-3 days
System boiler to combi boiler upgrade with relocation	2-3 days
Combi boiler to system boiler upgrade with relocation	2-3 days

This is a category for all boiler fitting jobs that include relocation. So, you will notice that the table consists of both like-for-like replacement and boiler upgrade jobs. The table also shows that boiler relocation is the most time-consuming type of boiler fitting job.

Boiler relocation often involves extensive modification of the existing boiler framework. The installer has to redirect the pipework and electricity lines, reconnect the flue, and probably move the thermostat. They may also need to modify the building. These modifications alone can add an extra 12 hours of work time.

There are several reasons to relocate a boiler. Examples include space and noise issues.

Additional Tasks and Factors That Affect How Long It Takes to Fit a Boiler

Any task or issue that can complicate and increase the job’s workload will influence how long it takes to fit a boiler. Here are three prime examples.

Boiler Framework Upgrades and Repairs

An example of such upgrades is the issue of upgrading 15mm gas supply pipes to 22mm. Any credible installer will tell you that this is necessary. In fact, they will assess your existing boiler framework and suggest necessary repairs and upgrades before fitting the new boiler.

Heating System Upgrades

You can use this opportunity to install a central heating system or upgrade an existing one. However, you should know that heating system installations often take up to one week or more. 

House Repairs

The old boiler may have caused damage to the floor and wall plaster near it. The time it takes to fix this will also affect how long it will take to fit the boiler.  

Conclusion

Once again, the answer to your question depends on the circumstances of the job. Like-for-like boiler replacements don’t require much effort and skill. Therefore, they don’t take long. Boiler relocation jobs are the exact opposite. Consequently, they take longer.

Boiler fitting takes an average of 4 hours to 3 days. However, duration is not that important in the grand scheme of things. It’s more important to have the boiler appropriately installed.

That’s why we recommended hiring Gas Safe Registered engineers. It’s also why we are offering our service. At BPS Plumbing and Heating, we are Gas Safe Registered engineers and experts on boiler fitting.