Best Consumer Unit Blanks for Safety: 2025 Expert Review
Oli
Owner, OR Electrics & 18th Edition Electrician
If there is one thing that makes an electrician sweat during an inspection, it is seeing a gaping hole in a consumer unit where a breaker used to be. In the trade, we call this a breakdown of IP4X barriers—basically, it means a child's finger or a tool could touch a live 230V busbar. It is an immediate danger.
In Leeds, particularly in the older rental stock, I often find boards where DIY enthusiasts have removed a fuse and left the slot open. This is a guaranteed failure on an Electrical Installation Condition Report (EICR). The solution is simple: a properly fitted blanking plate.
In this review, I'm covering three options to improve your consumer unit's safety: a budget plastic strip for quick fixes, a robust metal solution for modern fire-rated boards, and a high-quality sub-unit for when you need to expand safely rather than just blank off a spare way.
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Specs vs. The Real World
The Spec: "Universal Fit Claims"
"Many blanks claim to fit 'all' consumer units regardless of brand."
In reality, consumer units have subtle differences in busbar height and cover cut-outs. 'Universal' toggle blanks often rattle or sit loose. Securing them properly sometimes requires a bit of modification or purchasing brand-specific clips.
The Spec: "Plastic vs Metal"
"Plastic blanks are sufficient for all domestic boards."
Since the 18th Edition Amendment 3, domestic consumer units should be non-combustible (metal). Whilst plastic blanks are allowed inside, fitting cheap, flimsy plastic into a robust metal fire-rated board can be a weak point. I always recommend metal blanks for metal boards.
My Top 3 Recommendations
Three options to cover different needs and budgets
2 X Consumer Unit - Distribution Board Blanking Strip MCB Blanks (2 Pack)
LKS
These plastic blanking strips are the bread and butter of quick remedial work in older boards. If you have a standard plastic consumer unit with a missing MCB, these strips can be cut to size to fill the gap effectively.
The Good
- Extremely affordable
- Can be cut to length to cover multiple ways
- Universal fit for most standard DIN rail cut-outs
The Bad
- Flimsy compared to module blanks
- Can be pushed out if not secured well from the inside
Installer Tip:
Don't just snap these in from the front and hope for the best. To do it properly, take the front cover off (safely, with power off!) and clip them securely from the back of the fascia. This stops them being pushed in by a curious child.
Priced at £2.75 at the time of writing
Check Price on AmazonUadme Consumer Unit 4 Way Fuse Box, Leakage Circuit Breaker Box 63A 30mA RCD with 4 MCBs
Uadme
Sometimes, blanking off a spare way isn't the solution—you actually need more safe space. If your main board is crammed or you are running power to a garage, this 4-way unit is a high-quality alternative to trying to squeeze modules into a full board.
The Good
- Includes RCD protection specifically for this sub-circuit
- Comes populated with MCBs (6A, 20A, 32A)
- Perfect for garages or extensions where the main board is full
The Bad
- More complex installation than a simple blank
- Requires connecting into the main supply
Installer Tip:
If you are finding yourself constantly blanking off problematic circuits in an old board, it might be safer to move those circuits to a dedicated sub-board like this. It isolates faults (like a tripping garage freezer) from your main house lights.
Priced at £24.99 at the time of writing
Check Price on AmazonMetal Consumer Unit Blanks, White, Steel, Universal Fit, Single Module (10)
A1 ELECTRICS
With modern regulations requiring metal consumer units in domestic properties to contain fire, putting a plastic blank in a metal board can be a weak link. These steel blanks are the professional's choice for modern compliance.
The Good
- Maintains the non-combustible integrity of metal boards
- Strong and impossible to push through accidentally
- Colour-matched for standard white metal units
The Bad
- Slightly harder to fit than snap-in plastic types
- Conductive material (must ensure internal clearances)
Installer Tip:
When fitting metal blanks, ensure they are tightly screwed or clipped in. Because they are conductive, if they fall inside onto the busbar, it goes 'bang' very loudly. Always isolate the board before fitting these.
Priced at £7.95 at the time of writing
Check Price on AmazonFrequently Asked Questions
What happens if I leave a gap in my consumer unit?
Can I fit a consumer unit blank myself?
Are plastic blanks allowed in metal consumer units?
My consumer unit is full; what should I do?
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