Lighting Circuit Faults · Kettering & Northamptonshire · NAPIT-Registered

Light Not Working or Flickering?

A flickering light is easy to ignore. A light that's stopped working is easy to assume is just a bulb. But both can point to wiring faults that get worse over time — and in some cases, are genuinely dangerous. Let us find the real cause.

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Understanding the Fault

What a Flickering or Dead Light Usually Means

When a light stops working or starts flickering, the instinct is usually to change the bulb. Sometimes that's all it is. But if the problem persists, or if it's affecting multiple fittings, the fault is almost certainly somewhere in the wiring — not the lamp.

The location and pattern of the fault tells us a lot before we even open a screwdriver. A single fitting that's completely dead usually points to that fitting, its switch, or its supply cable. A whole lighting circuit that's dropped off means the MCB or RCBO at the consumer unit has tripped, or the circuit has a fault severe enough to cause an overcurrent. Flickering across multiple lights on one circuit — or across the whole property — suggests something further back in the system: loose connections at the consumer unit, a failing main switch, or in rare cases, a problem with the incoming DNO supply.

The pattern matters. That's why we ask questions before we attend, and why we don't start guessing once we arrive.

Electrician testing a lighting circuit at ceiling rose in Kettering property
What We Look For

Common Causes We Check For

In no particular order — the pattern of the fault guides our starting point.

Loose terminal connectionsLoose terminations at the switch, ceiling rose, junction box, or consumer unit are the most common cause of flickering and intermittent faults. The connection has enough contact to carry current most of the time, but arcs under load — generating heat and, over time, damage. This is also a leading cause of electrical fires.
Dimmer switch incompatibilityOlder leading-edge dimmer switches were designed for incandescent and halogen loads. Many LEDs — especially budget fittings — flicker on these dimmers because the minimum load threshold isn't met, or the driver is incompatible with the dimmer's phase-cutting waveform. The fix is often replacing the dimmer with a trailing-edge or universal LED dimmer.
Failing switch mechanismA worn or faulty light switch can cause intermittent flickering, especially under load or when the contacts inside have oxidised. We test the switch by measuring continuity across the switching terminal — a result that opens and closes cleanly at the switch but behaves erratically at the fitting points to the switch or the cable back from it.
Damaged cable or degraded insulationOlder properties in Kettering — particularly 1930s–1970s semis in Headlands, Brambleside and Barton Seagrave — may have rubber or early PVC-insulated cables that have become brittle with age. Damaged insulation can cause current to leak to earth, tripping the RCBO, or cause intermittent loss of continuity as the cable flexes under thermal expansion.
Water ingress into a fittingA common cause in bathrooms, kitchen ceilings (below bathrooms), loft spaces and porches. Water tracking into a recessed downlight or pendant fitting can trip the RCBO immediately, or cause a slow corrosive fault that manifests as intermittent flickering before the fitting fails completely. IP ratings matter — and many fittings in older properties weren't IP-rated at all.
Tripped MCB or RCBOIf an entire lighting circuit has gone off, the first check is the consumer unit. A tripped MCB means the circuit drew more current than the breaker allows — usually a short circuit or a severely damaged cable. An RCBO trip means there's a current leakage to earth somewhere on that circuit. Both need investigation before simply resetting.
Failed LED driver or transformerLow-voltage downlights use an electronic driver (LED) or transformer (older 12V halogen replacements). These fail — often silently — and the symptom is a fitting that stops working or flickers while the rest of the circuit is fine. The fitting may feel warm or have a faint buzzing quality before it fails completely.
Whole-house or multi-circuit flickeringIf lights are flickering throughout the property — or on multiple circuits simultaneously — the fault is likely before the consumer unit. This can be a loose main switch within the board, an issue at the meter tails, or in some cases a problem with the DNO's incoming supply. The latter is not the homeowner's responsibility to fix, but it needs correctly identifying first.
When to Treat This as Urgent

When a Flickering Light Is Not a Minor Inconvenience

Flickering lights are often dismissed because they don't immediately cause harm. But the fault that causes flickering — particularly a loose connection or damaged cable — can generate heat at that point that the circuit protection won't detect until it becomes a more serious fault. Electrical fires in UK homes typically start this way: a loose terminal arcing at low load for weeks or months before it generates enough heat to ignite adjacent material.

Contact Us Today If You Notice:

  • Flickering that affects multiple rooms or the whole property simultaneously
  • A burning smell, warm switchplate, or discolouration around a fitting or switch
  • A buzzing or crackling sound from a fitting, switch, or consumer unit
  • The MCB or RCBO keeps tripping every time you reset it
  • A light that stopped working in a bathroom or kitchen where water may be involved
  • Any flickering in a property with older rubber-insulated wiring
  • Flickering that gets worse when other heavy appliances come on
How We Approach It

How Entigen Diagnoses a Lighting Fault

01
Triage Before Attendance
We ask about the fault pattern — one fitting, one circuit, or whole house — before we arrive. This shapes what equipment we bring and where we start. It also lets us confirm whether this is urgent.
02
Consumer Unit Inspection
We check the consumer unit first — are MCBs or RCBOs in the tripped position? We note whether they're Type B or C, whether there's SPD fitted, and look for any signs of heat damage or discolouration around terminals.
03
Circuit Isolation and Testing
Using a calibrated multifunction tester, we carry out insulation resistance testing on the lighting circuit — measuring L-N, L-E and N-E values at 250V or 500V DC depending on the circuit. This quickly shows whether the cable is compromised or a fitting is leaking.
04
Accessory and Fitting Checks
Each fitting and switch on the affected circuit is checked for terminal tightness and continuity. Loose connections often show up clearly here. We check switching terminals, common terminals and switch-wire continuity at each access point.
05
Root Cause Confirmed, Repair Quoted
Once the fault is identified, we explain it clearly and provide a fixed price before starting any repair. There are no assumptions, no guesswork, and no surprises on the invoice.
Common Questions

Lighting Fault FAQs

The most common causes in UK homes are loose terminal connections at the switch, fitting or consumer unit; incompatible LED drivers on older dimmer circuits; a failing switch; a damaged lighting circuit cable; or, in whole-house cases, a problem with the incoming DNO supply. An electrician will test each circuit systematically to identify the root cause — a process that typically takes under an hour.
It depends on the cause. Flickering caused by a loose connection can lead to arcing, which generates heat and is a genuine fire risk — even if no circuit protection has tripped. Flickering across multiple lights or whole circuits, or flickering accompanied by a buzzing sound or burning smell, should be treated as urgent. A single flickering LED on a dimmer circuit is often just a compatibility issue, but it still warrants checking.
If an entire lighting circuit has gone off, the most likely cause is a tripped MCB or RCBO in the consumer unit. If the MCB won't reset or keeps tripping, there is an underlying fault — usually a failed fitting, damaged cable, or water ingress. If individual lights have stopped working but the circuit is live, the fault is usually at the fitting, the switch, or the supply connection to that point.
If a bulb is loose in its holder, re-seating it is safe. Beyond that, any work involving the wiring, switch mechanism, ceiling rose, or consumer unit should be carried out by a qualified electrician. Loose terminations in particular can be dangerous — they are one of the leading causes of electrical fires in UK homes and may not show any obvious outward signs before they cause damage.
Most lighting faults are identified within 30–60 minutes. We carry out insulation resistance testing, continuity checks and a systematic check of each access point on the circuit. Intermittent faults — where the problem only appears under load or at certain temperatures — can take longer, but the testing process will still narrow down the cause even if the fault isn't immediately active.
Fault Support

If your issue sounds similar, these pages may help you understand the fault before getting in touch.

Got a Lighting Fault in Kettering or Northamptonshire?

Don't leave a flickering light until it becomes a bigger problem. We'll find the root cause — properly, with test equipment — and fix it right first time.

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