UK Bathroom Electrical Zones: BS 7671 Guide for Electric Towel Radiators

When installing an electric or dual fuel towel radiator in a UK bathroom, the electrical installation must comply with the applicable requirements of BS 7671 (IET Wiring Regulations), the manufacturer's installation instructions and relevant Building Regulations.

Bathrooms and shower rooms require particular consideration because electrical equipment may be installed close to water. BS 7671 therefore defines electrical zones around baths and showers and sets requirements for equipment installed in these locations.

Important: This guide provides general information and is not a substitute for the current applicable edition of BS 7671, manufacturer instructions or professional electrical advice. Bathroom electrical work should be assessed and carried out by a suitably competent person.

What Are UK Bathroom Electrical Zones?

Bathroom electrical zones define areas around baths and showers where additional electrical requirements apply. The exact boundaries depend on the bathroom layout and the type of bath or shower installation.

The position of the towel radiator, heating element, electrical connection, controls and isolation equipment should therefore be considered as part of the complete installation.

Where equipment is likely to be exposed to water jets, a higher degree of water protection may be required. The IP rating is only one part of determining whether equipment is suitable for a particular location.

Bathroom Zone 0

Zone 0 is the interior of the bath or shower basin.

Electrical equipment installed in Zone 0 is subject to particularly strict requirements and generally requires at least IPX7 protection against water ingress, together with the other electrical requirements applicable to Zone 0.

A conventional mains-powered electric towel radiator or standard IP55 towel radiator heating element should not be assumed suitable for Zone 0.

Bathroom Zone 1

Zone 1 is generally the area directly above the bath or shower basin up to 2.25m above finished floor level, although the precise boundary depends on the installation arrangement.

Electrical equipment installed in Zone 1 generally requires at least IPX4 protection against water ingress. Where equipment is likely to be exposed to water jets, a higher degree of protection may be required.

Certain fixed and permanently connected electrical equipment may be installed within Zone 1 where it is permitted for the location, provides the required protection and is installed according to the manufacturer's instructions and applicable BS 7671 requirements.

An electric towel radiator should therefore not automatically be considered suitable for Zone 1 simply because its heating element has an IP44, IP55 or higher IP rating. The complete appliance and installation arrangement must be considered.

Bathroom Zone 2

Where Zone 2 applies, it generally extends 0.6m horizontally beyond the boundary of Zone 1.

Electrical equipment installed in Zone 2 generally requires at least IPX4 protection against water ingress.

An IP55 heating element exceeds IPX4 in terms of water-ingress protection, but this does not by itself establish that the complete towel radiator installation is suitable for Zone 2. The product instructions and complete installation requirements must still be followed.

Showers Without a Basin or Tray

The zone arrangement can be different for a shower without a basin or shower tray.

For relevant fixed shower arrangements without a basin, the horizontal extent of Zone 1 can extend 1.2m from the centre point of the fixed water outlet. In this arrangement there is no separate Zone 2 beyond it.

This is why measurements such as 0.6m and 1.2m should not be applied universally to every bathroom. The actual bath, shower and bathroom configuration must first be identified.

What Do Bathroom IP Ratings Mean?

An IP rating (Ingress Protection rating) describes the level of protection provided by an electrical enclosure against solid objects and water.

The first digit relates to protection against solid objects and dust, while the second digit relates to protection against water ingress.

IP44 vs IP55 for Towel Radiator Heating Elements

IP55 does not mean waterproof. The IP rating alone also does not determine whether an electric towel radiator or heating element is suitable for a particular bathroom zone. The complete installation, manufacturer's instructions and applicable BS 7671 requirements must also be considered.

What Does IP55 Mean for an Electric Towel Radiator?

Many electric towel radiator heating elements are available with an IP55 rating. IP55 describes the protection provided by the electrical enclosure against solid particles and water ingress.

For an IP55-rated towel radiator heating element:

• First digit – 5: the enclosure is dust protected. Some dust may enter, but not in sufficient quantity to interfere with satisfactory operation.
• Second digit – 5: the enclosure is protected against water jets from any direction.

This gives an IP55 element a higher ingress-protection rating than IP44 for both solid-particle and water protection.

However, IP55 does not mean waterproof and should not be interpreted as permission to install the product anywhere within a bathroom.

Can an IP55 Towel Radiator Heating Element Be Installed in Zone 1 or Zone 2?

From an ingress-protection perspective, an IP55 heating element exceeds the general IPX4 minimum water-protection requirement associated with bathroom Zones 1 and 2.

However, the IP rating is only one part of determining whether an electric towel radiator installation is suitable for a particular bathroom zone.

An IP55 rating does not automatically mean that the complete towel radiator can be installed in Zone 1 or Zone 2. The installer must also consider:

• The towel radiator manufacturer's installation instructions
• The heating element manufacturer's instructions
• The suitability of the complete radiator and element combination
• The position of the electrical connection
• The position and suitability of controls
• Switching and isolation arrangements
• Required 30mA RCD protection
• The applicable requirements of BS 7671

30mA RCD Protection in Bathrooms

RCD protection is an important part of bathroom electrical safety.

Low-voltage circuits serving a location containing a bath or shower require additional protection by one or more RCDs with a rated residual operating current not exceeding 30mA, subject to the applicable requirements of BS 7671.

This is particularly relevant when installing electrical bathroom equipment such as an electric towel radiator or electrically heated towel rail.

An IP55 rating and RCD protection perform different functions. The IP55 rating relates to ingress protection, while the RCD provides additional electrical protection as part of the installation.

Electric Towel Radiators in Bathroom Zones

Isolation, Switching & Controls

An electric towel radiator requires appropriate switching, isolation and circuit protection as part of the electrical installation.

• Follow the radiator and heating element manufacturer's instructions.
• Provide appropriate means of isolation and switching.
• Ensure switches, fused connection units and other electrical accessories are positioned where permitted.
• Ensure controls are suitable for their intended location.
• Provide the required RCD protection.
• Consider possible direct water exposure when positioning electrical accessories.

The correct arrangement depends on the product, bathroom layout and electrical installation. A particular fused spur, switch or control position should therefore not be assumed suitable without assessing the installation.

Part P and Bathroom Electrical Work in England

In England, Part P of the Building Regulations covers electrical safety in dwellings.

Electrical installation work associated with a bath or shower may also be subject to Building Regulations notification requirements depending on the nature and location of the work.

A registered Competent Person Scheme installer may be able to self-certify qualifying electrical work and deal with the relevant Building Regulations notification.

Building Regulations and electrical-safety arrangements differ across the UK, so installations outside England should be checked against the requirements applicable in that nation.

Electric-Only vs Dual Fuel Towel Radiators

An electric-only towel radiator operates independently from the central-heating circuit using a compatible electric heating element or integrated electric heating system.

A dual fuel towel radiator combines a radiator connected to the central-heating system with a compatible electric heating element. This allows the towel radiator to be operated electrically when the central heating is switched off.

Not every towel radiator can be converted to electric-only or dual fuel operation. Always check the radiator design, connection size, internal capacity, element wattage and manufacturer's instructions.

For a more detailed comparison, read our Electric vs Dual Fuel Towel Radiators Guide.

Converting a New Towel Radiator to Standalone Electric

A compatible new, unfilled towel radiator can be configured for standalone electric-only operation using an appropriate electric heating element, fittings and approved heating fluid.

Our installation guide explains the basic process, including fitting the heating element, air vent and blanking plug, filling the radiator and preparing it for electrical connection.

View the Standalone Electric Towel Radiator Installation Guide (PDF)

This guide is intended for a new, unfilled towel radiator being configured for electric-only operation. Always follow the instructions supplied with the specific radiator and heating element.

Bathroom Electric Towel Radiator Installation Checklist

• ✔ Identify the bath and shower arrangement.
• ✔ Establish the applicable Zone 0, Zone 1 and Zone 2 boundaries.
• ✔ Check the required IP protection.
• ✔ Check whether the heating element is IP44, IP55 or another rating.
• ✔ Check the towel radiator manufacturer's instructions.
• ✔ Check the electric heating element manufacturer's instructions.
• ✔ Confirm that the complete product is suitable for the intended location.
• ✔ Confirm appropriate 30mA RCD protection.
• ✔ Check switching, isolation and electrical connection arrangements.
• ✔ Ensure controls and electrical accessories are suitable for their intended locations.
• ✔ Check applicable Building Regulations requirements.
• ✔ Have the installation inspected and tested as required.

Frequently Asked Questions

What IP rating is required in bathroom Zone 1?

Electrical equipment installed in Zone 1 generally requires at least IPX4 protection against water ingress. Where equipment is likely to be exposed to water jets, a higher degree of protection may be required. Other equipment-specific and electrical installation requirements also apply.

What IP rating is required in bathroom Zone 2?

Electrical equipment installed in Zone 2 generally requires at least IPX4 protection against water ingress. The equipment must also be suitable for its intended location and installed according to the manufacturer's instructions.

What IP rating is required in bathroom Zone 0?

Electrical equipment installed in Zone 0 generally requires at least IPX7 protection against water ingress, together with the other specific electrical requirements applicable to Zone 0.

What does IP55 mean on a towel radiator heating element?

An IP55 rating means the enclosure is dust protected and protected against water jets. The first digit, 5, relates to protection against dust ingress, while the second digit, 5, relates to protection against water.

Is IP55 better than IP44?

Yes, in terms of ingress protection. IP55 provides a higher level of protection against both solid particles/dust and water than IP44. IP44 protects against solid objects larger than 1mm and splashing water, while IP55 is dust protected and provides protection against water jets.

Is an IP55 heating element suitable for a bathroom?

An IP55 towel radiator heating element provides protection against dust ingress and water jets. However, IP55 alone does not establish whether the element or complete towel radiator installation is suitable for a particular bathroom zone. The manufacturer's instructions and complete electrical installation must also be considered.

Can an IP55 towel radiator heating element be installed in Zone 1?

From an ingress-protection perspective, IP55 exceeds the general IPX4 water-protection requirement associated with Zone 1. However, this does not automatically make the complete towel radiator suitable for Zone 1. Product suitability, electrical connections, controls, manufacturer instructions, RCD protection and applicable BS 7671 requirements must also be considered.

Can an IP55 towel radiator heating element be installed in Zone 2?

From an ingress-protection perspective, IP55 exceeds the general IPX4 water-protection requirement associated with Zone 2. However, the complete product and installation must still be suitable for the location and comply with the manufacturer's instructions and applicable electrical requirements.

Does IP55 mean waterproof?

No. IP55 provides protection against dust ingress and water jets, but it does not mean the product is waterproof or suitable for immersion in water.

Do electric towel radiators need RCD protection?

Low-voltage circuits serving a location containing a bath or shower require additional protection by an RCD with a rated residual operating current not exceeding 30mA, subject to the applicable requirements of BS 7671.

How far does bathroom Zone 2 extend?

Where Zone 2 applies, it generally extends 0.6m horizontally beyond the boundary of Zone 1. Different arrangements apply to some showers without a basin or tray, so the actual bathroom layout must be considered.

Does a shower without a tray have Zone 2?

For relevant shower arrangements without a basin, Zone 1 can extend horizontally up to 1.2m from the centre point of the fixed water outlet, with no separate Zone 2 beyond it.

Can an electric towel radiator be installed outside the bathroom zones?

Positioning an electric towel radiator outside the defined bathroom zones generally removes some zone-specific restrictions, but the equipment and electrical installation must still be suitable for the bathroom environment and comply with applicable electrical requirements.

Related Electric Towel Radiator Guides & Products

For more information about choosing between electric-only and dual fuel heating, read our Electric vs Dual Fuel Towel Radiators Guide.

If you are converting a new, unfilled towel radiator to electric-only operation, see our Standalone Electric Towel Radiator Installation Guide (PDF).

Ready to choose an element? Browse our Electric & Dual Fuel Towel Radiator Elements for electric heating elements and dual fuel components.

For valves, T-pieces, reducers and other installation components, browse our Towel Radiator & Radiator Accessories.

Current BS 7671 Requirements

BS 7671 is periodically updated. Installers should therefore refer to the current applicable edition of the IET Wiring Regulations and the latest installation instructions supplied by the radiator and heating element manufacturers.

Simplified bathroom-zone diagrams and online guides are useful for understanding the general principles, but they should not replace an assessment of the actual bathroom layout and electrical installation.

Trade Summary

For an electric or dual fuel towel radiator, IP rating is only one part of bathroom electrical safety.

An IP55 heating element provides greater ingress protection than an IP44 element. IP44 protects against solid objects larger than 1mm and splashing water, while IP55 is dust protected and provides protection against water jets.

From a water-ingress perspective, IP55 also exceeds the general IPX4 protection associated with bathroom Zones 1 and 2. However, IP55 alone does not make a towel radiator automatically suitable for either zone.

The actual bathroom zone, complete product suitability, electrical connection, controls, isolation, 30mA RCD protection, manufacturer instructions and applicable requirements of BS 7671 must all be considered.

Always refer to the current applicable requirements of BS 7671 and use a suitably competent person for bathroom electrical installation work.