Why Bathroom Electrics Fail EICR Inspections: The Issues We See Every Week
If you asked our engineers which room causes the most EICR failures, they would not need to think about it. It is the bathroom. Every time.
Bathrooms combine water, steam, bare skin and electricity in a small enclosed space. The wiring regulations treat them differently from every other room in a building, and for good reason — the consequences of a fault in a bathroom are far more serious than a fault in a hallway. Yet bathrooms are also the room most likely to have been altered by someone who did not fully understand the zone rules, the IP rating requirements, or the bonding obligations.
We carry out hundreds of EICRs across Greater Manchester every month. The same five bathroom issues appear on report after report. This page explains each one, what causes it, what it costs to fix, and how to avoid it in the first place.
Quick answer: The five most common bathroom EICR failures we see are missing supplementary bonding, incorrect bathroom zones for installed equipment, absent or inadequate RCD protection, wrong IP-rated fittings in wet areas, and pull-cord switches replaced with standard plate switches. Most can be fixed for between £150 and £600. If your EICR has flagged bathroom defects, call 0161 706 1360 for a remedial quote — we usually attend within the week.
Issue 1: Missing or Inadequate Supplementary Bonding
This is the single most common bathroom defect we record.
Supplementary bonding connects all exposed metalwork in a bathroom — radiator pipes, towel rails, waste pipes, bath taps, shower pipework — to the earth system via a dedicated bonding conductor. Its purpose is to ensure that if a fault occurs, all the metal parts a person could touch are at the same voltage. Without it, a fault on one fitting could make one piece of metal live while another remains at earth potential. A person touching both becomes the path for the fault current.
Why it goes missing. In older properties, supplementary bonding may never have been installed — it was not required before the 16th Edition of the wiring regulations. In renovated bathrooms, bonding conductors get removed during refits. A plumber replaces copper pipework with plastic and assumes the bonding is no longer needed. A tiler covers up the bonding clamp on a waste pipe. A new bath panel hides a disconnected conductor.
What the EICR will say. Typically a C2 observation: potentially dangerous. The inspector will note that supplementary bonding is absent or incomplete to one or more extraneous conductive parts.
What it costs to fix. Between £150 and £350, depending on how many items need bonding and how accessible the pipework is. The work takes one to three hours.
The exception. If the installation is protected throughout by 30 mA RCD protection with a confirmed disconnection time of 0.04 seconds or less, and the main protective bonding is confirmed as adequate, supplementary bonding in the bathroom may not be required under the current edition of BS 7671 (Regulation 701.415.2). However, this must be verified by testing — it cannot be assumed. Many inspectors will still flag the absence if they cannot confirm the conditions are met.
Issue 2: Equipment in the Wrong Bathroom Zone
BS 7671 divides the bathroom into zones based on proximity to water sources. Each zone restricts what equipment can be installed there.
Zone 0 is inside the bath or shower tray itself. Almost nothing electrical can go here — only SELV (Separated Extra Low Voltage) equipment rated at maximum 12 V.
Zone 1 is directly above the bath or shower tray, up to 2.25 metres from the floor. Only fixed equipment suitable for the zone can be installed — typically showers, instantaneous water heaters, and IP-rated light fittings. Everything must be at least IPX4 rated against water splashes.
Zone 2 extends 0.6 metres horizontally from the edge of Zone 1, and includes the area above Zone 1 up to 3 metres from the floor. Shaver sockets to BS EN 61558-2-5 are permitted here. Light fittings must still be at least IPX4.
Outside the zones is everywhere else in the bathroom. Standard accessories are permitted, though RCD protection is still required for socket outlets.
What goes wrong. The most common zone violation we see is a standard ceiling rose light fitting installed directly above a shower or bath. It was put there during a bathroom refit by someone who did not consider the zones. We also regularly find socket outlets inside Zone 2 that are not shaver units, and extractor fans in Zone 1 that are not IP-rated for that position.
What the EICR will say. Usually C2 or C3 depending on the severity. A standard light fitting in Zone 1 is a C2. An incorrectly rated fan in Zone 2 may be a C3 if it has been there for years without incident, but an inspector can reasonably code it C2.
What it costs to fix. Replacing a ceiling light fitting with a correctly rated IP-rated unit: £80 to £200. Relocating a socket or fan to the correct zone: £200 to £500 depending on the cable route.
Issue 3: No RCD Protection on Bathroom Circuits
Since the 17th Edition of the wiring regulations, all circuits in rooms containing a bath or shower must be protected by a 30 mA RCD (residual current device). This applies to the lighting circuit, the shower circuit, the fan circuit and any socket circuit serving the bathroom.
Why it is missing. In properties with older consumer units — particularly rewireable fuse boards or early MCB boards without RCDs — bathroom circuits are often protected only by an MCB or fuse. The circuit works. The lights come on. The shower heats water. But there is no RCD to detect a small earth leakage fault and disconnect the supply in milliseconds before it causes injury.
What the EICR will say. C2: absence of RCD protection to circuits in a room containing a bath or shower. This is one of the most clearly defined requirements in the regulations and inspectors will code it consistently.
What it costs to fix. If the consumer unit can accept an RCBO (a combined RCD and MCB), fitting one costs £150 to £250 per circuit. If the consumer unit is too old or too full, a replacement consumer unit is the better solution — typically £600 to £1,200 including the unit, installation and certification. A consumer unit upgrade resolves this issue across all circuits, not just the bathroom.
Issue 4: Wrong IP-Rated Fittings in Wet Areas
IP ratings define how well an enclosure protects against the ingress of solid objects and water. The two-digit code tells you what it can withstand — the first digit covers solids (dust), the second covers water.
In bathroom Zones 1 and 2, fittings must be rated at least IPX4, which means protected against water splashing from any direction. In Zone 0, the requirement is IPX7 — protection against temporary immersion.
What goes wrong. Standard domestic light fittings, downlights without fire hoods or IP-rated covers, and extractor fans rated only for general indoor use all turn up in wet zones during EICRs. Sometimes the fitting was IP-rated when installed, but the bathroom has been refitted around it — a shower tray has been moved, or a bath repositioned — and the fitting that was outside Zone 1 is now inside it.
What the EICR will say. C2 or C3 depending on the zone and the fitting type. A non-IP-rated downlight directly above a shower is a C2. A borderline fitting at the edge of Zone 2 might receive a C3.
What it costs to fix. Replacing a light fitting with an IP65-rated alternative: £60 to £180. Replacing a non-IP-rated fan with one suitable for Zone 1: £200 to £400 fitted.
Issue 5: Pull-Cord Switches Replaced with Plate Switches
The wiring regulations do not permit standard plate switches inside Zone 1 or Zone 2 of a bathroom. The reasoning is obvious — a wet hand operating a switch with mains voltage behind a flat plastic plate is a shock risk. Pull-cord ceiling switches are used instead because the operating mechanism is separated from the switch body by the length of the cord, and the switch itself is typically ceiling-mounted above head height.
What goes wrong. During a bathroom refit, the original pull-cord switch is removed and a standard rocker switch is fitted on the wall, often to match the rest of the house. We see this frequently in rental properties where cosmetic refurbishment has been done by a general builder rather than an electrician. We also see it in en-suites where a bedroom light switch is positioned on a wall that happens to fall inside Zone 2 of the adjacent shower.
What the EICR will say. C2: non-compliant switch within bathroom zone. This is a clear regulatory breach and will always be coded as potentially dangerous.
What it costs to fix. Replacing a plate switch with a pull-cord switch: £100 to £200. If the cable route needs adjusting to reach a ceiling-mounted switch, the cost may reach £300.
How to Avoid Bathroom EICR Failures
The single best thing you can do is use a registered electrician — NICEIC, NAPIT or ELECSA — for any bathroom electrical work. Part P of the Building Regulations classifies electrical work in rooms containing a bath or shower as notifiable work in most cases. A registered electrician can self-certify the work and will know the zone requirements, bonding obligations and IP rating standards.
If you are having a bathroom refitted, make sure the electrician is involved from the planning stage, not called in after the tiler has finished. The zone layout depends on where the bath, shower and basin are positioned. Once the tiles are on the wall, moving a light fitting or socket is significantly more expensive.
For landlords managing multiple properties, consider commissioning an EICR before a bathroom refit rather than after. If the existing installation has defects, you can include them in the scope of the refit work and avoid paying for a separate remedial visit.
Book a Bathroom-Focused EICR or Remedial Visit
If your EICR has flagged bathroom defects, or if you have had bathroom work done and want to confirm it is compliant, call 0161 706 1360. We carry out EICRs and remedial work across Greater Manchester — Salford, Stockport, Oldham, Tameside, Rochdale, Bolton, Bury, Wigan and Trafford — and we can usually attend within the same week.
Email: hello@manchestercompliance.co.uk Phone: 0161 706 1360 Address: 25 Holden Clough Drive, Ashton-under-Lyne, OL7 9TH