Fused Spur vs 20A Switch vs 45A Switch: Which One Do You Need?

Choosing the correct switch isn't just about matching your interior style—it also ensures your electrical installation is safe, compliant and suitable for the appliance you're controlling.

Here's a simple guide to help you understand the difference between a Fused Spur, 20A Double Pole Switch, and 45A Double Pole Switch.

What is a Fused Spur?

A Fused Spur, also known as a Fused Connection Unit (FCU), contains a replaceable fuse that protects the appliance connected to it.

Unlike a standard switch, the fuse limits the amount of current that can reach the appliance, helping to protect smaller electrical equipment from overloads.

Common applications

• Boilers
• Extractor fans
• Lighting circuits
• Heated towel rails
• Alarm systems
• Fixed appliances requiring fused protection

Most fused spurs use a 3A, 5A or 13A fuse, depending on the manufacturer's requirements for the connected appliance.

Choose a fused spur if:

• The appliance manufacturer specifies fused protection.
• You're connecting equipment to a higher-rated circuit, but the appliance requires a lower level of protection.
• You want local isolation and overcurrent protection in one unit.

What is a 20A Double Pole Switch?

A 20A Double Pole Switch is designed for appliances that draw more current than a standard fused spur but do not require an integrated fuse.

Retrotouch 20A switches isolate both the live and neutral conductors, providing complete electrical isolation during maintenance or servicing.

Common applications

• Electric heaters
• Underfloor heating
• Air conditioning units
• Water heaters
• High-power extractor systems

Choose a 20A switch if:

• Your appliance is rated up to 20 amps.
• Circuit protection is already provided by the consumer unit.
• The appliance instructions call for a dedicated isolator rather than a fused spur.

What is a 45A Double Pole Switch?

A 45A Double-Pole Switch is intended for high-current appliances requiring a heavy-duty isolating switch.

Like the 20A version, it disconnects both live and neutral for improved safety.

Common applications

• Electric cookers
• Ceramic hobs
• Induction hobs
• Large range cookers
• Other high-power kitchen appliances

These switches are designed to safely handle much higher electrical loads than a standard FCU or 20A switch.

Choose a 45A switch if:

• You're installing an electric cooker or hob.
• The appliance requires a 32A or 45A circuit.
• A cooker isolator is specified by the installation instructions.

Quick Comparison

Which One Should You Buy?

Choose a Fused Spur when your appliance requires its own fuse for protection.

Choose a 20A Double-Pole Switch for medium-power fixed appliances such as underfloor heating, electric heaters, or air conditioning units.

Choose a 45A Double-Pole Switch for high-power kitchen appliances, including electric cookers and hobs.

When replacing an existing accessory, it's important to match both the current rating and the appliance manufacturer's installation requirements. If you're unsure, always consult a qualified electrician.

Retrotouch 20A & 45A Switch Features

Retrotouch's 20A and 45A switches are designed with:

• Double-pole switching for complete isolation of live and neutral
• Modern decorative finishes to complement contemporary interiors
• Standard wiring terminals for straightforward installation by a qualified electrician
• Durable construction suitable for residential and commercial installations

Always isolate the mains supply before carrying out any electrical work and ensure products are installed in accordance with the current edition of BS 7671 and relevant Building Regulations.