Does every kitchen appliance need a local isolator?

BS 7671 Regulation 537.3.1 requires a means of isolation for every fixed appliance that is accessible without danger to the person operating it. For washing machines, dishwashers and fridge freezers fitted inside units where the plug is behind the machine and inaccessible, a switched fused connection unit within 2 metres satisfies this. An EICR inspector will code the absence of local isolation as a C2 or C3 fault depending on how inaccessible the existing plug is.

Can I just use a normal socket instead of an FCU?

A socket outlet accessible without moving the appliance can count as the means of isolation if the plug can be reached safely. The problem with built-in kitchen appliances is that the socket is typically hidden behind the machine inside a unit, which makes it inaccessible without pulling the appliance out. In that situation, a switched FCU mounted on the wall or on the face of the unit satisfies the regulation.

What size fuse should I use in the FCU?

For a washing machine or dishwasher (typically 10 A to 13 A load), use a 13 A fuse. For a fridge freezer (usually 1 A to 3 A), a 3 A or 5 A fuse protects the appliance supply cable more accurately than a 13 A fuse would. Do not use a fuse rated higher than the supply cable can carry: 2.5 mm cable is protected by 13 A, 1.5 mm cable by 10 A or less.

Is adding an FCU Part P notifiable work?

Adding a fused spur from an existing ring in a non-kitchen room is generally not notifiable under Part P in England. However, any new circuit work in a kitchen is technically within the scope of Part P-notifiable work. In practice, many electricians treat a simple spur addition in a kitchen as minor and self-certify through their Part P scheme. If you are doing this yourself, check current Building Regulations guidance or use a registered electrician.

Wire Kitchen Appliance Isolators (UK): Fridge, Washing Machine, Dishwasher

Helpful video reference. This January 2026 tutorial, "Kitchen Ring Circuit Isolator -- How I Wire Fridge, Washer and Dishwasher Safely (UK)", shows the complete process of adding switched fused connection units from the kitchen ring circuit for three common built-in appliances. It is UK-specific throughout: ring circuit terminology, correct cable sizes, and BS 7671 isolation requirements. Watch it alongside the steps below to see exactly how the ring tapping and FCU connections look in practice.

Before you start. Switch the kitchen ring off at the consumer unit, not just at the wall switch. Some kitchens have two ring circuits: check that both relevant rings are dead before working in any back box. Test dead with a two-pole voltage tester at the socket you intend to tap from. Do not work on a ring that has any sign of damage, scorching or overloading at the sockets.

1. Understand the requirement and choose your FCU

A switched fused connection unit (SFCU) is a surface-mount or flush-mount box that contains a fuse, a rocker switch and two sets of terminals: Feed (incoming from the ring) and Load (outgoing to the appliance). When the switch is off, the supply to the appliance is broken. That is what BS 7671 requires.

You need one SFCU per appliance. For a fridge freezer, washing machine and dishwasher, that is three units, each wired as a separate spur from the ring. They can be mounted above the worktop, on the side of a unit, or in a tall larder unit where they are accessible without tools.

Fuse ratings: 13 A for the washing machine and dishwasher (both typically draw 10--13 A). Use a 3 A or 5 A fuse for the fridge freezer, which rarely exceeds 3 A running, to give the flex better overcurrent protection.

2. Isolate the ring circuit at the consumer unit

Switch off the kitchen ring MCB. Confirm dead at the socket nearest your intended tapping point with a two-pole tester. If the kitchen has two rings (common in larger kitchens or those with separate appliance and counter circuits), isolate both.

Leave a note on the consumer unit or tape the MCB in the off position so nobody restores it while you are working.

3. Confirm the tapping socket is a genuine ring socket

A spur must be taken from a ring socket, not from another spur. Open the socket you plan to tap from (with the circuit isolated) and count the cable entries. A genuine ring socket has two sets of conductors: one pair coming in, one pair going out. If there is only one cable, that socket is already a spur and cannot have a further spur taken from it. Find another socket on the ring instead.

4. Mark out, cut and fix the back boxes

Decide on the FCU positions. They should be within 2 m of each appliance and accessible without moving the appliance. Above the worktop is easiest to access. On the end panel of a kitchen unit is common where worktop space is tight.

Cut the holes for dry-lining or plaster-depth back boxes, or surface-mount boxes if you prefer. Fix the boxes securely. If the wall is solid, use a cold chisel and bolster or an SDS drill to chase out a flush recess.

5. Run the spur cables

Run 2.5 mm twin and earth from the tapping-point socket to each FCU position. In plastered walls, run cables vertically up from the socket to a height of 150 mm above the finished floor, then horizontally to the FCU position (the cable safe zone). In stud walls, run cables through the cavity as required. Surface-run cables in mini-trunking if chasing is not possible.

6. Wire the tapping-point socket

At the ring socket you are tapping from, add the new spur cable alongside the existing ring conductors at the same terminals:

Brown conductor of spur to the L terminal (with existing brown ring conductors).
Blue conductor of spur to the N terminal (with existing blue ring conductors).
Green-and-yellow conductor of spur to the earth terminal.

If you are tapping three spurs from the same socket, that is three additional conductors per terminal. Most modern back-to-back socket terminals will accept this. Check each conductor is fully inserted and clamped. Tighten firmly but not so hard that you cut into the copper.

7. Wire each FCU

At the FCU, two sets of terminals are marked FEED (or IN) and LOAD (or OUT):

FEED terminals: connect the spur cable from the ring. Brown to L, blue to N, green-and-yellow to earth.
LOAD terminals: connect the appliance supply cable. Brown (or sleeved) to L, blue to N, green-and-yellow to earth.

If the FCU has an integral socket outlet on the LOAD side, simply plug the appliance into that socket. If the FCU terminates into a direct hard-wired connection, run 1.5 mm twin and earth (sufficient for a fridge freezer) or 2.5 mm (for a washing machine or dishwasher) to the appliance's supply terminals per the appliance manufacturer's instructions.

Check the correct fuse is in the fuse carrier. For a 13 A FCU with a fridge freezer supply, change the default 13 A fuse to a 3 A or 5 A.

8. Restore power and test

Refit all faceplates. Remove the consumer unit note and restore the ring MCB. Test each FCU with a socket tester or plug in the appliance and confirm it runs. Operate the FCU switch and confirm the appliance loses power when the switch is off.

If the MCB trips on restoration, switch everything back off and check for a wiring error — almost always a crossed conductor or a pinched insulation under a terminal screw.

Stop and call an electrician if: you find the kitchen has only a single 30 A rewireable fuse rather than a ring (old installations sometimes had a radial), if any socket shows scorch marks or melted plastic, if you cannot identify which socket is a ring socket, if the existing cable is rubber-sheathed or cloth-covered, or if the MCB trips when you restore power and you cannot identify why.

When to call us

Fitting FCUs is routine electrical work. Where it gets complicated is when the kitchen has old wiring, no ring circuit, or the EICR flags multiple issues at the same time. If your inspector has flagged missing isolation as a C2 and you want it sorted properly and re-certified, Richard covers kitchens across Sandwich, Deal, Dover and surrounding east Kent.

Need kitchen isolators fitted in east Kent?

Richard wires FCUs for fridges, washing machines and dishwashers, and can provide a minor works certificate on completion. Small jobs at the £10 per 10-minute rate.

Contact Richard

How to wire isolator switches for kitchen appliances