How Much
to Change a
Consumer Unit?

A walk-through of consumer unit replacement pricing

Consumer unit replacement pricing varies based on board type, circuit count plus property-specific factors. Five aspects deserve detailed attention to understand pricing plus compare quotes meaningfully.

Board types plus typical pricing

Three main board types account for most UK domestic consumer unit replacements. Dual RCD board: most basic option meeting current regulations. Two RCDs (Residual Current Devices) split circuits into two groups. If one RCD trips, half the house loses power until reset. Typical cost £500 to £700 for a 6 to 10 circuit board including install, certification plus testing. RCBO board: every circuit has its own dedicated RCBO (Residual Current Breaker with Overcurrent). If one circuit trips, only that circuit loses power. Better fault discrimination plus more practical for daily use. Typical cost £700 to £900. RCBO plus AFDD board: RCBOs plus AFDDs (Arc Fault Detection Devices) on key circuits. AFDD detects arc faults that RCDs cannot. Mandatory in HMOs plus recommended for premium installs. Typical cost £900 to £1,200. High integrity board: split RCDs plus dedicated RCBOs for sensitive circuits like fire alarms. Typical cost £750 to £950. For most UK homes: RCBO board offers the best balance of cost, daily practicality plus fault protection.

What is included in a typical quote

A reputable consumer unit replacement quote should include several specific items. The new consumer unit: metal enclosure compliant with BS 7671 18th Edition. Brands like Hager, Wylex, MK or Schneider typical. RCDs or RCBOs as specified: appropriate trip ratings (typically 30mA for socket circuits, 100mA for some larger circuits). Main switch: typically 100A double-pole isolator. Removal of old unit: safe disposal of the old consumer unit including any asbestos-containing material if present. Circuit testing: full insulation resistance, polarity, earth fault loop impedance plus RCD trip time tests on each circuit. Electrical Installation Certificate (EIC): signed by qualified electrician confirming compliance. Building Control notification: NICEIC or NAPIT registered electrician self-certifies plus registers the work under Part P with Building Control. 6-year insurance-backed warranty. Labour: typical 1-day install. Power off for 4 to 6 hours. What may not be included: SPD if not in original quote, supply upgrade if existing supply insufficient or remedial work to bring circuits up to 18th Edition standard.

Factors that increase cost

Several factors can push pricing above the typical ranges. High circuit count: properties with 12+ circuits (large detached homes, properties with extensions, properties with EV chargers, electric heating or hot tubs). Each additional circuit typically adds £30 to £60 in RCBO cost plus testing time. Surge protection device (SPD): BS 7671 increasingly recommends SPD for transient overvoltage protection. Typical £80 to £150 for the device plus install. Mandatory in some scenarios under 18th Edition. AFDD modules: Arc Fault Detection Devices add £40 to £60 per module. Mandatory on socket circuits in HMOs, student accommodation plus care homes. Recommended elsewhere. Supply upgrade: if existing supply (typically 60A or 80A) cannot handle modern load (especially with EV charger, heat pump or electric shower), supply upgrade to 100A typical £300 to £600 separately from CU upgrade. Coordinate with DNO (Distribution Network Operator). Remedial works: faulty circuits found during testing may need fixing. Earth bonding upgrades, faulty cabling, broken sockets or non-compliant wiring methods. Cost variable from £100 to £500+. Difficult access: CU in awkward location requiring more time. Typical £50 to £150 added.

What can lower cost

Several factors can keep pricing toward the lower end. Standard installation: existing CU in accessible location with good cable routing already in place. Lower circuit count: 6 to 8 circuits typical for smaller flats or maisonettes. Pricing toward £500 to £700 even for RCBO board. Recent rewire: if circuits were recently tested plus brought up to 18th Edition standard, less remedial work required. Group bookings: some installers offer reduced day rate for landlords with multiple properties. Off-peak booking: weekday non-summer install typically slightly cheaper than peak periods. Standard board type: dual RCD remains the cheapest fully compliant option. Suitable where simple protection is sufficient. Avoiding "while you're here" extras: stick to consumer unit replacement only without bundling kitchen rewires, garden lighting or other works that should be quoted separately. For typical 3-bed UK home: expect £600 to £900 for RCBO board with full certification.

Comparing quotes plus finding good value

Three or four written quotes is the typical approach. What to compare: like-for-like board specification (dual RCD vs RCBO vs RCBO+AFDD must match). Brand of consumer unit (Hager, Wylex, MK, Schneider all reputable, generic budget brands variable). Inclusion of certification (EIC plus Part P registration must be included). Days plus power-off duration. Any remedial work scope. Red flags: significantly under £500 for full RCBO upgrade likely missing certification or using budget components. Quotes that are unclear about what is included. Cash-only deals avoiding registration. Installers without NICEIC or NAPIT registration. Reasonable expectations: registered electrician day rate £200 to £400 plus parts £200 to £600 plus testing time. Total in £500 to £1,200 range typical. Quality indicators: NICEIC or NAPIT registered, written quote with clear scope, EIC plus Part P notification included, willing to explain board type choice plus installation options. For Milton Keynes plus surrounding areas: typical local pricing aligns with UK average.

• Board type spread. Dual RCD £500-£700, RCBO £700-£900, RCBO+AFDD £900-£1,200.
• Circuits matter. 6 to 8 typical for flats. 10 to 12+ for larger detached homes.
• Add-ons. SPD £80-£150, AFDD modules £40-£60 each, supply upgrade £300-£600.
• Standard inclusion. New CU, RCDs/RCBOs, testing, EIC plus Part P registration.
• Install time. Typically 1 day with 4-6 hour power-off window.

For a fixed-quote consumer unit replacement matched to your property circuit count plus board preference, our Consumer Unit Upgrades Milton Keynes service handles assessment, board specification plus install with full electrical certification.

This article is one chapter of a wider local resource. To see how consumer unit pricing connects with upgrade decisions, plastic vs metal plus the bigger picture, head to our full Consumer Units hub. The hub indexes every related article we have written for local property owners.

For a fixed-quote consumer unit replacement matched to your property circuit count plus board preference, our Consumer Unit Upgrades Milton Keynes service handles full assessment plus install with NICEIC certification. Workmanship across Milton Keynes plus surrounding postcodes.