James Elston

James Elston

Published March 27, 2024

According to UK law, yes, you can install a boiler in your bathroom. However, there are a few regulatory and safety considerations to take into account. The bathroom, under the right conditions, is a great location for boiler installation.

In this article, we will look at what you need to take into account to install a boiler in your bathroom safely and legally. We will also look at the pros and cons of installing a boiler in your bathroom and what types of units are best suited to this location.

3 Considerations When Installing Your Boiler In A Bathroom

Let’s look at the three key areas you need to consider according to government regulatory requirements for a proper boiler installation in your bathroom.

1. Electrical safety

Use a qualified boiler installer

All boiler installations in a bathroom must be done by technicians who are qualified in electrical work and registered with a UK regulatory body, like the National Inspection Council of Electrical Installation Contracting (NICEIC).

If you want to have your boiler in your bathroom, you must start the process with a reputable company that can complete the work safely and according to UK regulatory standards. Otherwise, you risk your safety and your boiler warranty.

Contact us and make use of Eco Happy’s quote comparison service to find the most affordable and qualified local installers in your area – and get your job done the right way.

Install in the correct bathroom zones

For electrical building regulations, your bathroom is divided into four bathroom zones. These zones start at your bath or shower area and extend in circles outward from this point. Zone 3 is considered the safe zone, while zones 0, 1, and 2 are considered dangerous zones where the installation of any electrical equipment is risky.

  • Zone 0: This zone is directly within your bath or shower tray. In this zone, water and electrical equipment being close together provide a hazard.
  • Zone 1: This zone exists directly above zone 0, up to 2.25 m from the floor.
  • Zone 2: This zone exists from the end of zone 1, to 0.6 m away, and a further 2,25 m above it.
  • Zone 3: This zone is any area beyond the first 3 zones, but within 3 m on the horizontal plane, away from zone 2.

Correct Ingress Protection (IP) ratings 

The IP rating determines how protected a piece of equipment or wiring is from both physical damage and water damage. When you look at a piece of electrical equipment’s IP rating, it will be written as IP45, for example. The “4” here is the physical protection rating and the “5” is the water protection rating.

So, for example, a combi boiler may have an IPX3 rating. This means it has a protection rating of 3 against any water penetration. If you want any electrical equipment within bathroom boiler zones 0 to 2, they must have a minimum IP rating for water protection of 4.

  • Zone 0 – IPX7 or higher
  • Zone 1 – IPX4 or higher
  • Zone 2 – IPX4 or higher
  • Zone 3 – No minimum IP requirement due to significantly reduced risk of water ingress.

RCD protection

An RCD, or Residual Current Device, is essentially a circuit breaker. RCDs are required by UK bathroom regulations to be installed with any piece of electrical equipment in the bathroom.

These devices will immediately cut power through any electrical circuit that exceeds an operating current above 30 mA. This means that if any kind of short occurs, the device will kick in and save your property and, potentially, your life.

2. Gas safety regulations

Use Gas Safe installers

To meet safety regulations, a bathroom gas boiler installation must be done by a Gas Safe registered engineer (certified as part of the UK’s Gas Safe Register). Only qualified and registered engineers have the competencies required for a proper and safe boiler installation.

Adequate air circulation

There are two things to consider when it comes to air circulation in your bathroom:

  • Boiler flue location: The boiler flue should be properly installed to funnel all combusted gases from the unit to the exterior of the building.
  • Airflow for combustion: Your boiler needs to receive adequate airflow for combustion to take place. Inadequate ventilation could lead to the unit not operating optimally and cause a build-up of carbon dioxide within the bathroom.

Carbon monoxide alarm

Carbon monoxide alarms are essential to have when using a gas boiler. They provide an early warning of gas leaks and will save you from carbon monoxide poisoning. Because this alarm will be located in the bathroom, make sure that the model you use is sufficiently water-resistant.

3. Building regulations

Building bathroom regulations include both electrical and gas safety standards in its framework, but there are a few other considerations also.

Fire safety considerations

Your boiler in the bathroom should be located away from fire hazards. For example, bathroom accessories like toilet paper and towels, as well as flammable bathroom fixtures like curtains should not be close to a combustion boiler. Enclosure materials and pipe insulation materials for the boiler cabinet must be appropriately fire-resistant to meet UK regulations.

Access for maintenance

Whenever possible, the boiler should be fitted in a location that is easily accessible for any maintenance technicians. This means that the unit shouldn’t ideally be installed directly above your bathtub where an engineer would struggle to reach it (or adequately and safely set up a ladder to reach it).

Structural considerations

Installing a boiler must be done in a way that doesn’t compromise the structural integrity of a room or building. For example, a boiler should always be installed with the outside wall providing the structural support for its weight.

A closed and sealed boiler cabinet

Some units can be installed within a closed cabinet; however, there are strict regulations determining the dimensions required within the cabinet.

Manufacturer instructions require specified gaps between your boiler and the boiler cupboard perimeters to ensure optimal performance. Gaps need to be located at the bottom and to the sides, with specific dimensions depending on the unit’s make and model.

Advantages And Disadvantages Of A Boiler In A Bathroom

Let’s talk about the advantages and disadvantages of installing a boiler in a bathroom.


  • Saving space: The biggest advantage of installing a boiler in your bathroom is, of course, the space you will save in the rest of your home. This is especially helpful in a smaller living space where the unit may have taken up valuable closet space or kitchen space.
  • Practical location for pipework: Your bathroom is one of the rooms your boiler will service most, which means having a boiler right there gives you hot water faster. It will also limit the heat loss the water would experience travelling through the pipework in your home. On top of this, the boiler installed will also have easy access to waste pipes for drainage.
  • Noise reduction: While most boilers aren’t exactly a source of major noise pollution, they do still make some sound. Having your boiler in the bathroom will mean less noise in your living space.


  • Safety concerns: Even with all the UK’s bathroom regulations, it is still inherently unsafe to have an electrical or gas boiler in your bathroom. While you can lower the risks involved, the risk factor will never be zero. Bathroom space regulations are there for a reason.
  • Moisture damage: Your bathroom is a wet area that generally will have high humidity at points throughout the day. This can result in moisture-related problems for your equipment down the line.
  • Space considerations: While one of the pros of having your boiler in your bathroom is that it frees up space in the rest of the house, it will still mean that the unit now takes up space in this room.
  • Proper ventilation requirements: Your gas boilers will need a bathroom with proper airflow. This is not just for safety but for adequate operation of the boiler. Your bathroom may need additional work done or have equipment installed to provide the ventilation needed by gas boilers.

Types Of Boilers To Install In A Bathroom

Let’s look at the different types of boilers and which ones are the best fit for a bathroom installation.

Combi boilers

Combi boilers are an excellent option to have in a bathroom. They are often small and compact, ideal for the limited space in a bathroom. You can have a look at the best small combi boilers that we recommend.

Compact boilers

Compact boilers are specifically designed boiler models that are smaller and more compact than their standard counterparts. They are the perfect units to have in a bathroom. While they are designed to make great cupboard boilers, they are not ideal for homes with large hot water requirements.

System boilers

System boilers consist of two parts – the actual boiler unit and the hot water cylinder. Due to their larger design, system boilers may not be ideal for bathroom installations. That is, unless you have the hot water storage and the boiler installed in two separate rooms.

Conventional boilers

Conventional boilers consist of a boiler, a hot water storage tank and a cold-water storage tank. Conventional boilers are generally larger and they need more space than a combi boiler, for example. This makes them a poor option for a boiler in a bathroom.


Can I move my boiler to the bathroom myself?

No. Moving your boiler location to a bathroom requires qualified boiler installers. Mixing electricity, water and potentially dangerous gas is a recipe for disaster when installing a boiler as a DIY project.

Can you put a boiler above a toilet?

When you install a new boiler in a bathroom, it should not be mounted directly above the toilet. It would not be easily accessible for maintenance. It will also place the unit’s electrical components too close to a water source.


Under the right circumstances and with the right care, a boiler installed in a bathroom is a fantastic idea. As long as you work with qualified boiler technicians, you will get many advantages by moving your boiler to the bathroom. Visit Eco Happy for more information on the best boilers and the best installation companies for your heating needs.

James Elston

James Elston

Boiler Expert

James Elston is the top boiler replacement and heating expert at Eco Happy. He has over 20 years of experience in the industry, focusing on Gas Safe boiler installations and offering home-heating and energy-saving solutions to homeowners across the UK. From sourcing the most energy-efficient combi boiler to providing specialist heating advice, James ensures that Eco Happy maintains the highest standards and best customer service.

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