This article is for information only and is not electrical advice. Wiring regulations (BS 7671), building regulations (Part P) and individual installations vary, and every circuit has to be assessed on its own merits. Always follow your qualified electrician’s judgement, and never attempt DIY electrical work — in England and Wales, electrical installation work must be carried out and certified by a competent person.
You chose the cooker, paid for it, and booked an electrician to connect it. Then the fitter opens the consumer unit, shakes their head: “I can’t connect this.” No argument, no negotiation — and suddenly a heavy new appliance is sitting in your kitchen with nowhere to go.
The maddening part is that it often doesn’t look like a problem. Your electrician refused to wire in your cooker, yet the wiring looks tidy, the old cooker worked fine and the new one is brand new — so what are they actually worried about? Almost always, one of a handful of genuine, verifiable issues, and understanding them is the difference between feeling fobbed off and knowing exactly what to ask next.
Electrician Refused to Wire In Your Cooker? Here’s Why
Electricians don’t refuse out of caution for its own sake: connecting the cooker would be unsafe, non-compliant, or both — and in England and Wales, signing off non-compliant work is a Part P offence that can cost them their registration. The usual reasons, roughly in order of frequency:
- The cable is too small. A dedicated cooker circuit is normally 6mm² twin-and-earth cable on a 32A MCB or RCBO, with larger cookers on 10mm² cable and a 45A breaker. If the cable feeding your cooker point is 2.5mm² or 4mm² — the sort that feeds sockets — it was never designed for a big cooker, and no breaker swap will fix that: the cable is buried in the wall, so fixing it means a new circuit.
- The breaker is too small, or the consumer unit is full. A 16A or 20A breaker can’t protect a circuit that needs 32A, and a full consumer unit can’t take a new circuit without an upgrade or a small sub-board.
- The consumer unit is outdated. Old fuse-wire boards, and boards with no RCD protection, often can’t legally take a new circuit without upgrading the whole unit — and since 2016 new consumer units must be metal-enclosed. If you’re looking at fuse wire and a wooden backboard, the refusal isn’t about the cooker; it’s about the board.
- Earthing or bonding is missing or substandard. A cooker is a large metal appliance with a big connected load: if the earthing conductor is undersized, or the main bonding to gas and water isn’t up to standard, a responsible electrician won’t energise the circuit until it’s put right.
- Part P notification. Adding or altering a cooker circuit is notifiable work in England and Wales. The electrician must certify it and notify building control through their registered scheme (NICEIC or NAPIT); if it can’t be certified, it can’t be connected.
In short, a proper cooker circuit looks like this:
| Circuit type | Cable | Breaker | Typical use |
|---|---|---|---|
| 32A cooker circuit | 6mm² twin-and-earth | 32A MCB/RCBO (B32 or C32) | The standard UK cooker circuit — most domestic cookers and hobs, including many ~13kW models once diversity is applied (below) |
| 45A cooker circuit | 10mm² twin-and-earth | 45A MCB/RCBO | Very large cookers, range cookers with multiple ovens, or long cable runs where voltage drop demands a bigger cable |
The Diversity Rule: Why a 32A Circuit Can Legally Feed a Bigger Cooker
This is where most of the confusion starts. You look at the cooker’s rating plate, it says 13.6kW, you do the maths — 13,600W ÷ 230V ≈ 59A — and your circuit is only 32A. How can that possibly be legal?
The answer is the diversity rule in BS 7671, the UK’s wiring standard (currently the 18th Edition). Diversity is the principle that a cooker never draws its full connected load for long: the heating elements cycle on and off through their thermostats, and you rarely run every ring and both ovens flat out at once — and even then only for minutes. BS 7671’s diversity table for cooking appliances reflects that by letting the electrician size the circuit on a reduced design current rather than the full appliance rating.
For a cooker, the standard formula is:
First 10A of load + 30% of the remaining load + 5A if the cooker switch incorporates a socket outlet
Let’s run it for that 13.6kW cooker:
| Step | Calculation | Result |
|---|---|---|
| Full load at 230V | 13,600W ÷ 230V | ≈ 59A |
| First 10A taken in full | 10A | 10A |
| 30% of the remainder | 0.3 × (59 − 10) = 0.3 × 49 | ≈ 14.7A |
| Socket outlet on the cooker switch | +5A | +5A |
| Design current after diversity | 10 + 14.7 + 5 | ≈ 29.7A |
29.7A is comfortably under 32A — which is exactly why a 32A circuit with 6mm² cable can legally serve a cooker whose nameplate current is nearly double the breaker rating. If you’ve ever wondered whether your kitchen actually has a 32A cooker circuit, this is the maths your electrician is doing while they look at your consumer unit.
Three things to remember. First, diversity is a design tool: the electrician sizes the cable and breaker for the calculated design current, including run length — a long run needs a bigger cable regardless of the arithmetic. Second, the cable must still be installed properly; diversity doesn’t shrink the copper in the wall. Third, this is a worked example of a general principle, not a guarantee that your cooker will be fine on your circuit — the electrician’s professional judgement, based on the actual installation, always wins. Background for an informed conversation — not a licence to override your electrician with a calculator.
Why Diversity Does Not Mean ‘Anything Goes’
Diversity is not a loophole for bolting a huge cooker onto whatever circuit is nearby. It only applies when the circuit was designed and installed for the purpose — a dedicated cooker circuit with the correct cable, sized using the diversity calculation. It absolutely does not mean you can:
- Plug a big cooker into a socket circuit. A standard 2.5mm² socket circuit is designed for appliances up to around 3,000W (13A). A 13.6kW cooker on sockets would overload the ring, melt plugs and trip the breaker within minutes.
- Swap a small breaker for a bigger one on the same cable. The breaker protects the cable — the cable must be rated for the breaker, never the other way round. Putting a 32A breaker on 2.5mm² cable is how fires start.
- Assume two cookers share one circuit. Diversity is applied to the circuit’s connected load; adding a second oven or a separate hob changes the calculation completely.
Electricians apply diversity conservatively: if the numbers are close, the terminations doubtful, or the cable run unknown, the safe answer wins — and it should. The 5A allowance for a socket on the cooker switch shows how the rule is calibrated: the circuit copes with the cooker’s realistic load plus a kettle in that socket, not everything at once.
What to Do If Your Electrician Refuses
- Ask for the reasons in writing. A good electrician will happily explain — cable size, breaker rating, board condition, what would need to change. “It can’t take it” with no detail is a red flag; “the cable is 2.5mm² and would need re-running in 6mm²” is a professional doing their job.
- Get a second opinion. Refusals should be consistent. Ask another electrician registered with a Part P scheme (NICEIC or NAPIT) to look — a second set of eyes sometimes spots a simpler path, like a spare way in the board or a 45A upgrade. And read what a cooker installation actually involves so you know what a fair quote looks like.
- Consider the 13A option. If the home genuinely can’t take a new circuit without a consumer unit upgrade (£400–£800+), or you’re renting and can’t touch the electrics, the practical solution is a cooker that runs off a normal socket. Plug-in mini ovens and countertop cookers rated under roughly 3,000W draw a maximum of 13A — exactly what a standard socket supplies. Our roundup of the best 13A plug-in cookers for UK flats and the freestanding cooker reviews cover both camps.
The Bottom Line
An electrician who refuses to connect your cooker is rarely being difficult. They’re telling you the circuit can’t support it — and the diversity rule in BS 7671, the reason a 32A circuit can legally feed a cooker rated at nearly 60A, is precisely why the correct fix is a properly designed circuit rather than a bigger fuse. Want to check your own setup first? Our guide to identify your breaker and wiring type takes ten minutes. And if the honest conclusion is that your home can’t take a built-in cooker without major work, a 13A plug-in cooker gets you cooking this week for a fraction of the install cost.