How Long Does It Take to Replace a Boiler?

If you’re considering a new boiler, one of the questions you’re likely to have is: how long does it actually take to replace one?

For a straightforward like-for-like boiler replacement, the work can often be completed within a day. However, more involved installations – such as changing boiler type, moving the boiler or making significant alterations to the existing heating system – can take longer.

Every home is different, so the exact timeframe will depend on your existing heating system and what you’re having installed.

Here’s what can affect how long your boiler replacement takes and what you can expect during the installation.

How Long Does a Straightforward Boiler Replacement Take?

If you’re replacing an existing boiler with a similar type of boiler in the same location, this is generally the most straightforward type of installation.

For example, replacing an existing combi boiler with a new combi in the same position will usually involve less work than changing the type or location of the boiler.

A straightforward replacement can often be completed within a working day, although the exact time required will depend on the installation.

Your engineer will need to:

• Safely disconnect and remove the old boiler
• Prepare the existing heating system
• Install and connect the new boiler
• Complete any required alterations
• Test and commission the boiler
• Check the heating system
• Set up the heating controls
• Explain how to use your new boiler

The boiler isn’t simply connected and switched on – appropriate testing and commissioning are an important part of the installation.

What Can Make a Boiler Replacement Take Longer?

Not every new boiler installation is a straightforward swap.

Several factors can increase the amount of work required.

Changing Boiler Type

Changing from one type of boiler to another can involve significantly more work than replacing like-for-like.

For example, converting from a traditional heating system with a hot water cylinder to a combi boiler may require changes to the existing pipework and removal of components that are no longer needed.

The suitability of any conversion will depend on your property and hot water requirements.

Moving Your Boiler

You don’t necessarily have to install your new boiler in exactly the same location as your old one.

However, relocating it can add to the installation time.

Your engineer may need to consider:

• New pipework
• Gas supply
• Flue position
• Condensate drainage
• Electrical connections
• Access to the proposed location

Moving a boiler a short distance may be relatively straightforward, while relocating it to another part of the property can involve considerably more work.

The Condition of Your Existing Heating System

Your boiler may be brand new, but it’s still being connected to the rest of your heating system.

If the existing system contains sludge or debris, appropriate cleaning or flushing may be required as part of the installation.

The condition of your radiators, pipework and heating controls may also need to be considered.

This doesn’t mean you automatically need a completely new heating system when replacing your boiler. In many homes, existing radiators and pipework can continue to be used if they’re in suitable condition.

Changes to the Flue

A boiler’s flue safely carries combustion gases outside the property.

If the new boiler has different flue requirements or you’re moving its location, alterations may be necessary to ensure the installation complies with current requirements.

Heating Controls

Replacing your boiler can also be a good opportunity to review how you control your heating.

Depending on the installation and package selected, new heating controls may be fitted and configured as part of the work.

Your engineer should then explain how to use them before completing the installation.

Will I Be Without Heating and Hot Water?

Yes, for at least part of the installation.

Your existing boiler will need to be isolated and removed before the new boiler can be connected, so your heating and/or hot water won’t be available while this work is taking place.

For a straightforward installation, this disruption may only be for the duration of the job.

If you’re having a more complex conversion or significant alterations carried out, your installer can explain what to expect beforehand.

Do I Need to Be at Home During a Boiler Replacement?

You’ll need to make sure the engineer can access your property and the areas required to complete the work.

It’s also helpful to be available at the beginning and end of the installation.

At the end of the job, your engineer can:

• Show you how the new boiler works
• Explain your heating controls
• Answer any questions
• Provide relevant documentation
• Explain ongoing servicing and maintenance requirements

If you can’t remain at home throughout the installation, discuss this with your installer beforehand.

What Should I Do Before My Boiler Installation?

There’s generally very little you’ll need to do.

Making sure there’s clear access around your existing boiler and any other areas the engineer needs to reach can help.

If your boiler is inside a kitchen cupboard, airing cupboard or another storage area, clearing belongings from around it beforehand can make access easier.

Your installer should let you know if there’s anything else you need to prepare.

What Happens After the New Boiler Is Installed?

Once your new boiler is physically installed, there’s still important work to complete.

Your engineer will test and commission the appliance to ensure it’s operating safely and correctly.

They should also check the heating system, set up any new controls and explain how everything works.

Depending on the boiler and installation, there may also be registration and manufacturer warranty requirements to complete.

It’s important to keep your boiler documentation somewhere safe and understand any servicing requirements associated with the warranty.

Can I Speed Up My Boiler Replacement?

The priority should always be ensuring the boiler is installed correctly and safely rather than simply completing the job as quickly as possible.

However, you can help make the process smoother by:

• Providing accurate information when requesting your quote
• Ensuring good access to the boiler
• Clearing the surrounding area
• Discussing any planned boiler relocation beforehand
• Mentioning any known problems with your existing heating system

Knowing the scope of the work in advance helps your installer prepare appropriately.

How Long Does an Oil-to-Gas Conversion Take?

An oil-to-gas conversion is different from a straightforward boiler replacement and can involve additional work.

The requirements will depend on the existing heating system, property and availability of a suitable gas supply.

If you’re considering moving from oil to gas, it’s best to discuss your property directly with a heating specialist rather than assuming the timescale will be the same as a standard boiler swap.

At solv, customers considering an oil-to-gas conversion can contact our team directly to discuss what’s involved.

How Can solv Help with Your Boiler Replacement?

At solv, we install replacement boilers for homeowners across Northern Ireland.

Whether you’re replacing an existing boiler or considering changes to your heating system, we’ll help you understand what’s involved and find a suitable option for your home.

We consider factors including:

• Property size
• Existing heating system
• Boiler type
• Hot water requirements
• Boiler location
• Heating controls
• Your individual requirements

The aim isn’t simply to replace your old boiler as quickly as possible – it’s to make sure your new heating system is right for your home.

Get an Instant Boiler Quote Online

If you’re thinking about replacing your boiler, you can start by using solv’s online quotation tool.

Simply answer a few questions about your property and existing heating system to explore suitable boiler and package options and get an indication of replacement costs.

If you’re looking to convert from oil to gas or have a more complex heating requirement, contact the solv team directly and we’ll help you explore your options.

Frequently Asked Questions

Can a boiler be replaced in one day?

A straightforward like-for-like boiler replacement can often be completed within a working day. More complex installations may take longer.

How long does it take to replace a combi boiler?

Replacing an existing combi with another combi in the same location is generally one of the more straightforward boiler replacements and can often be completed within a day, depending on the work required.

Does moving a boiler take longer?

Usually, yes. Relocating a boiler may require additional pipework and changes to the flue, drainage, gas supply and electrical connections.

Will I have hot water during a boiler replacement?

Your heating and/or hot water will be unavailable for at least part of the installation while your existing boiler is disconnected and the new boiler is installed.

Do I need new radiators when replacing my boiler?

Not necessarily. Existing radiators can often be retained if they’re appropriately sized, in good condition and suitable for your heating system.

Is replacing a boiler disruptive?

A straightforward replacement should generally involve relatively limited disruption. More extensive conversions or relocations can involve additional work, but your installer should explain what to expect before work begins.