Electric Hob Not Heating: Diagnostic Guide

Summary

Electric hobs come in three common types — solid plate (rare on modern installs), ceramic/radiant (glass-ceramic surface over resistance elements), and induction (electromagnetic coils that heat the pan directly, not the hob surface) — and each fails differently, which is why "the hob won't heat" needs triage by hob type before assuming a specific fault. A ceramic hob failing to heat is most often a dead element or a tripped thermal limiter; an induction hob failing to heat is more often a power electronics fault, a control board issue, or simply an incompatible pan than a heating "element" failure, since induction hobs have no resistive heating elements at all.

Unlike a gas hob fault, there's no equivalent statutory "Gas Safe only" restriction on who may investigate an electric hob — but the hazards are real and the competency bar still matters. Any fault-finding involving the fixed wiring, the cooker circuit, the isolator, or opening a hardwired connection to test for voltage requires safe isolation procedure and, for anything beyond simple component-level appliance repair, the competency expected of a qualified electrician working to BS 7671 (IET Wiring Regulations).

This guide covers the diagnostic path from "hob shows no sign of life" through to "hob powers on but one zone won't heat," separating what a general appliance-literate tradesperson can safely check (blown fuse in a plug-connected hob, tripped RCD, obvious pan-detection issue) from what needs an electrician (circuit fault, connector burn-out, internal wiring fault) or a qualified appliance engineer (element or PCB replacement with the correct safe isolation observed).

Key Facts

• Hob types — solid plate (older, rare), ceramic/radiant (glass-ceramic top over coiled/ribbon elements), induction (electromagnetic coil beneath a glass-ceramic surface, heats the pan directly via induced current, not the hob itself)
• Cooker circuit requirement — under BS 7671, a hob is typically supplied via a dedicated circuit sized to the appliance's rated load, using Appendix 15 diversity calculations where a hob and separate oven share supply; a 45A double-pole (DP) control switch or cooker connection unit within reach of the appliance is standard practice, though some smaller hobs use a fused connection unit or plug/socket where the manufacturer permits — see cooker circuits
• RCD/RCBO protection — modern circuits should have RCD or RCBO protection per BS 7671; a tripped RCD/RCBO cuts power to the hob entirely and is a common, easily-checked non-fault cause of "hob completely dead"
• Induction power draw — induction hobs typically draw 32-40A total depending on model and zone count, usually on a 6.0mm² T&E cable with a 32A or 40A MCB/RCBO — undersized or aged wiring on an older kitchen circuit that hasn't been upgraded for a newer, higher-power hob is a real cause of nuisance trips or voltage-drop-related faults
• Thermal cut-out (limiter) — ceramic and radiant hobs have a safety thermal cut-out that trips if the element overheats (commonly from a cracked glass top, a spillage insulating the element, or a failed thermostat allowing runaway temperature); once tripped, some models need a full power-cycle/reset, others need the fault cleared before they'll reset at all
• Pan detection (induction only) — induction hobs only heat when they detect a compatible ferrous (magnetic) pan base of a minimum size for that zone; a non-induction pan, a pan too small for the zone, or a pan not centred correctly will show a "no pan" indicator rather than heating — this is normal operation, not a fault
• Zone/control fault vs whole-hob fault — one zone not heating while others work normally points to a localised element, sensor, or zone-control fault; the whole hob being dead points to the supply, main control board, or a global safety lockout
• Cracked glass-ceramic top — a hairline crack in the hob's glass surface is a safety-critical fault; most manufacturers state the hob must not be used at all once the surface is cracked, and many models will safety-lockout automatically if crack-detection sensors are fitted
• Child lock / control lockout — a hob showing power (display lit) but not responding to any zone command is very often a lockout feature engaged, not a fault — check the manufacturer's unlock sequence before further diagnosis
• Overheat protection on the electronics (induction) — induction hobs have a cooling fan for the power module; a blocked vent (usually beneath the hob) can trigger thermal protection and shut zones down under sustained heavy use
• BS EN 60335-2-6 — the product safety standard for electric cooking ranges, hobs and ovens, relevant to internal fault diagnosis and component replacement
• Safe isolation — BS 7671 Regulation 643 (and associated GN3/HSE guidance) requires proving the circuit dead with an approved voltage indicator, proving the indicator on a known live source, before any hardwired connection is opened — this applies to hob fault-finding exactly as it does to any other fixed wiring work
• Part P notifiable work — replacing a hardwired hob on a like-for-like basis is generally not itself notifiable, but any new circuit, consumer unit alteration, or new cable run to supply the hob is notifiable under Building Regulations Part P and must be carried out or certified by a competent person

Quick Reference Table

Detailed Guidance

Step 1: Safe isolation before any inspection

Before opening any connection box, control panel, or removing the hob from its housing, isolate the circuit at the DP control switch or, if the fault might be upstream, at the consumer unit. Prove the circuit dead with an approved voltage indicator, and prove the indicator works on a known live source immediately before and after the dead test, per BS 7671 Regulation 643 and HSE Guidance Note GS38. This applies even to what looks like a simple appliance-level fault — an electric hob is a fixed, hardwired appliance in most UK domestic installs, not a plug-in item.

Step 2: Diagnostic tree

ELECTRIC HOB NOT HEATING — start here
│
├── Is the hob showing ANY sign of power (display, indicator lights)?
│     │
│     ├── NO POWER AT ALL
│     │     ├── Check DP control switch / isolator is ON
│     │     ├── Check RCD/RCBO at consumer unit — tripped?
│     │     │     ├── Resets and holds → likely nuisance trip,
│     │     │     │     monitor; if recurs, electrician required
│     │     │     └── Trips immediately on reset → DO NOT keep
│     │     │           resetting — internal fault likely,
│     │     │           electrician required for insulation/
│     │     │           fault-finding tests
│     │     └── Isolator and RCD both fine, still dead →
│     │           electrician to safe-isolate and test supply
│     │           at the hob connection point
│     │
│     └── SOME POWER PRESENT (display lit, lights on)
│           │
│           ├── Does the hob respond to touch/dial controls at all?
│           │     │
│           │     ├── NO — unresponsive to all controls
│           │     │     ├── Check for child lock/control lockout
│           │     │     │     — try manufacturer unlock sequence
│           │     │     └── Still unresponsive after unlock check
│           │     │           → control board/touch panel fault
│           │     │             → appliance engineer/electrician
│           │     │
│           │     └── YES — responds, but a zone won't heat
│           │           │
│           │           ├── ALL zones affected
│           │           │     ├── Check for thermal cut-out
│           │           │     │     code/indicator — spillage or
│           │           │     │     overheat lockout?
│           │           │     ├── Check glass-ceramic top for
│           │           │     │     cracks — STOP if cracked,
│           │           │     │     do not use, arrange
│           │           │     │     replacement
│           │           │     └── No crack, no obvious cause →
│           │           │           main control board/relay
│           │           │           fault → appliance engineer
│           │           │
│           │           └── ONE zone affected, others work fine
│           │                 ├── INDUCTION: check for
│           │                 │     "no pan" symbol → try known
│           │                 │     compatible pan, centred
│           │                 │     correctly on the zone
│           │                 ├── CERAMIC/RADIANT: suspect
│           │                 │     failed element or zone
│           │                 │     thermostat for that ring
│           │                 └── Confirmed component fault →
│           │                       appliance engineer/electrician
│           │                       for element/module replacement
│
└── Was the hob recently installed, moved, or worked on nearby?
      → check wiring at the connection point (with safe isolation
        observed) before assuming a manufacturing fault — a loose
        or reversed connection at first fit is a common cause of
        "brand new hob won't heat"

Ceramic and radiant hob element faults

Ceramic and radiant hobs use resistance heating elements beneath the glass-ceramic surface, each with its own thermostat/limiter and, on multi-power hobs, a control relay. A single zone failing to heat while others work normally points to that zone's element or its dedicated thermostat, not a whole-hob fault. Testing an element's continuity/resistance requires the hob removed and safely isolated — appliance-engineer or electrician work, not a visual check. A thermal cut-out tripped by a boiled-dry spillage will often reset once cooled, but repeated tripping without an obvious cause should be treated as a genuine thermostat/control fault, not reset repeatedly.

Induction hob power module and pan-detection faults

Induction hobs have no heating element to fail in the traditional sense — the pan itself is heated by induced current, and the hob's electronics generate and control that field. A zone showing "no heat" with a pan-detection symbol displayed is very often not a fault at all: check the pan is induction-compatible (a magnet will stick to a genuinely induction-suitable base), is a suitable size for the zone (undersized pans, particularly on larger zones, sometimes won't register), and is centred correctly. Where a known-compatible pan still fails to trigger heating on one zone while working on others, the fault is in that zone's power module or the main control board, which requires an appliance engineer or electrician to access and test — this is not user-serviceable.

Whole-hob failures and circuit-side faults

Where the hob shows no power at all, the fault is frequently upstream of the appliance: an isolator left off after other kitchen work, a tripped RCD/RCBO, or a fixed-wiring fault between the consumer unit and the hob's connection point. Never repeatedly reset an RCD/RCBO that trips immediately — this indicates a genuine fault (moisture ingress, a fault to earth, or damaged cable insulation) and repeated resetting risks further damage or masks a fire-risk fault. An electrician should safe-isolate, then carry out insulation resistance and continuity testing per BS 7671 before restoring supply.

When installation is the actual fault

A hob that has just been installed, or had other electrical work nearby, should have its connection checked before assuming a defective appliance. Common installation faults: a loose terminal at the hob's connection block, the wrong circuit rating for a higher-power induction hob replacing an older ceramic model without a cable/protective device upgrade, or an incorrectly rated plug and socket on a hardwired-only appliance. Confirming installation as the cause before ordering parts avoids an unnecessary appliance-engineer callout.

Frequently Asked Questions

Can I just reset the RCD/consumer unit myself if the hob trips it?

A single reset to confirm whether the trip was a one-off nuisance event is reasonable. If it trips again immediately or repeatedly, stop — this indicates a real fault, most likely a fault to earth somewhere in the hob or its circuit, and repeated resetting risks masking a developing fire-risk fault. Arrange an electrician for proper fault-finding.

The induction hob says "no pan" even though there's clearly a pan on it — is this a fault?

Usually not. Check the pan is genuinely induction-compatible (a magnet sticks firmly to the base — many "induction-labelled" budget pans have only a thin ferrous disc that doesn't register reliably), is centred on the zone, and is a suitable size for it. If a known-good pan still fails to register on that zone while working on others, it's a genuine pan-detection/zone-electronics fault needing an appliance engineer.

Is replacing a hob element or power module something I can do myself, or does it need an electrician?

It depends on competency and the specific job. Safe isolation and proving dead must be carried out to BS 7671 standard regardless of who does the work. Straightforward element replacement on a de-energised, disconnected hob is within scope for a competent appliance engineer; anything involving the fixed wiring connection, a new circuit, or a suspected fault at the consumer unit should go to an electrician, and new circuit work is notifiable under Part P.

The glass-ceramic top has a small crack but the hob still seems to work — is it safe to keep using?

No. Manufacturers are consistent on this: a cracked glass-ceramic surface is safety-critical regardless of whether the hob still functions, because the crack can allow spillage or moisture to reach live components beneath the surface. Advise the customer to stop using the hob immediately and arrange a replacement top or full unit — do not attempt to seal or repair a cracked hob surface.

Why does a new, more powerful induction hob trip the circuit when the old ceramic hob never did?

Induction hobs often draw significantly more current than the ceramic or radiant hob they're replacing, and older kitchen circuits were frequently sized for the lower-power appliance originally fitted. Before assuming a faulty new hob, check the circuit's cable size and protective device rating against the new hob's load and BS 7671 Appendix 15 diversity calculation — a straightforward swap may need the circuit upgraded, which is electrician work and may be notifiable under Part P if new cabling to the consumer unit is involved.

Regulations & Standards

• BS 7671 (IET Wiring Regulations), including Appendix 15 — diversity calculations for cooker/hob circuits and general wiring safety requirements

• BS 7671 Regulation 643 — safe isolation and dead testing requirements before working on fixed wiring or hardwired appliance connections

• BS EN 60335-2-6 — Household and similar electrical appliances — Safety — Particular requirements for stationary cooking ranges, hobs, ovens and similar appliances

• Building Regulations Part P (Electrical Safety) — notification requirements for new circuits or consumer unit alterations associated with hob installation

• Electricity at Work Regulations 1989 — general duty to ensure electrical systems are maintained to prevent danger, applicable to fault-finding and repair work

• HSE Guidance Note GS38 — electrical test equipment for use by electricians, relevant to safe isolation and proving-dead procedure

• gov.uk — Approved Document P: Electrical safety — Building Regulations Part P guidance

• HSE — Electricity at work: safe working practices — safe isolation and GS38 test equipment guidance

• BSI — BS 7671 IET Wiring Regulations — current edition and amendments

• NICEIC/NAPIT — competent person scheme guidance — Part P notification and competent person requirements

• gas hob not igniting — equivalent triage guide for gas hob ignition faults, contrasting the Gas Safe competency requirement

• cooker circuits — BS 7671 Appendix 15 demand calculation, dual appliance rule, DP control unit requirements

• induction hob installation — induction hob circuit sizing, MCB/RCD requirements, aperture and clearance detail

• hob installation pricing guide — pricing for hob installation and new circuit work