Electrical fault finding in Purley,traced to the source
£85 during standard hours covers the first hour of fault-finding, and that first hour is usually enough to tell you exactly what is wrong, what it costs to fix, and whether it is safe to keep using in the meantime.
NAPIT registered, £2 million insured, 10/10 on Checkatrade, 320 reviews logged over the years, 15 years tracing faults across Croydon and Surrey.
NAPIT registered
Government-approved competent person scheme
Part P registered
Domestic work certified to Building Regulations
£2 million cover
Public liability insurance on every job
1 year guarantee
Workmanship guaranteed for twelve months
10/10 on Checkatrade
320 reviews logged on the profile over the years
Service overview
Fault finding explained
A breaker that keeps tripping is telling you something. We test methodically rather than swapping parts and hoping, so you get a diagnosis and a fix rather than a repeat visit.
What it involves
Fault finding is systematic testing to locate the exact point of a failure in an electrical installation: a breaker that trips, a socket that is dead, lights that flicker or dim, a circuit that works until the shower comes on. Insulation resistance, continuity, polarity and earth loop impedance tests narrow the fault down circuit by circuit, then section by section within the circuit.
It is diagnosis, not part-swapping. The output is a clear answer, this cable, this accessory, this joint, this appliance, and a price to put it right.
Who it is for
Homeowners across Purley, Croydon and Surrey whose RCD keeps tripping and who have already tried unplugging everything. Landlords with a tenant reporting intermittent power. Shops and offices losing a section of lighting or a bank of sockets. Anyone who has had another electrician out, paid, and still has the fault.
When you need it
Call the moment a fault is repeatable. A breaker that trips once in a storm is one thing; a breaker that trips every time the kettle goes on is telling you a circuit is failing.
Call immediately, and outside hours if necessary, for a burning smell, a scorched or discoloured socket, a buzzing or crackling accessory, warm switch plates, or any shock, however small, from taps, appliances or fittings.
Why it needs a qualified electrician
The dangerous faults are the ones that do not trip anything. A loose connection generating heat inside a wall draws normal current and looks fine to a plug-in tester. Finding it takes proper instruments, a method, and experience of where these faults actually hide in local housing stock.
Guessing is also the expensive route. Replacing a consumer unit because it trips, when the real fault is water in an outside light, costs several hundred pounds and fixes nothing.
What happens if it waits
The cost of leaving it
An electrical fault left running does not stay the same size.
Risks and escalation
- Loose or corroded terminations heat up under load, char the accessory and can ignite the surrounding timber or plasterboard.
- Breakdown of cable insulation allows current to leak to earth, which eventually becomes a short circuit, or a live metal part someone touches.
- An RCD that is tripping is doing its job; defeating it by resetting repeatedly, or worse by bypassing it, removes the only protection standing between a fault and a person.
- Water ingress in outside lighting or garden supplies corrodes conductors progressively, so a nuisance trip becomes a dead circuit and a bigger repair.
- For businesses, an unresolved intermittent fault means the failure eventually happens at the worst possible moment, mid-trade, mid-service, or over a weekend.
Common mistakes we are called to undo
- Repeatedly resetting the breaker and hoping the fault clears itself.
- Replacing sockets or switches at random in the hope of hitting the right one.
- Fitting a larger breaker so it stops tripping, this removes protection from a cable that cannot carry the extra current.
- Calling out someone who charges by the hour with no test equipment and no method, so the meter runs while they guess.
Our £85 standard-hours call-out includes the first hour of fault-finding work, and the repair is quoted before it is carried out, you are never billed for work you did not agree to.
Our process
How the job runs, start to finish
Step 1
Symptoms and history
What trips, when, and what changed. Two minutes of the right questions frequently halves the search area before an instrument comes out of the van.
Step 2
Visual inspection and safe isolation
Board, accessories and any obvious damage checked, then the affected circuit safely isolated and proved dead before testing begins.
Step 3
Instrument testing
Insulation resistance, continuity, polarity and earth fault loop impedance tests split the circuit down until the faulty section, joint or accessory is identified.
Step 4
Diagnosis and quote
Jon explains what is wrong in plain English, what it will take to fix, and what it costs. You decide whether to proceed, often the repair happens on the spot.
Step 5
Repair, retest and guarantee
The fault is repaired, the circuit retested to confirm it is sound, results recorded on a Minor Works Certificate where applicable, and the work is guaranteed for one year.
What's included
Fault finding with JMO
- Tripping RCDs and MCBs, dead circuits, flickering lights, burning smells
- £85 call-out during standard hours, which covers the first hour of fault-finding work
- Evenings and weekends charged at £140 per hour
- Faults explained in plain English, with the repair quoted before we proceed
Costs, plainly
Free quotes on planned work. £85 call-out during standard hours, which covers the first hour of work on fault-finding jobs. Evenings and weekends £140 per hour. All workmanship guaranteed for one year.
Benefits
What you get out of it
Same-visit answers
Most faults are located within the first hour that your £85 call-out already covers.
Safety confirmed, not assumed
Testing proves the rest of the circuit is sound, rather than leaving you wondering what else is lurking.
No repeat visits
Diagnosing the cause rather than treating the symptom is what stops the same fault coming back in a fortnight.
Predictable cost
A known call-out rate during standard hours, £140 per hour evenings and weekends, and the repair priced before it starts.
Out of hours cover
Emergency response is available 24/7 for dangerous faults and total loss of power.
Written proof
Certification for the remedial work, which matters for landlords, insurers and letting agents.
In detail
Fault finding: the detail that matters
The faults we find most often
Local housing stock throws up recognisable patterns. In older Purley and Croydon properties it is frequently deteriorated cable at the ceiling roses or an unprotected cable nicked by a floorboard nail. In extended homes it is a junction box buried under insulation. In anything with a garden it is water in an external light or a damaged buried cable.
- Nuisance RCD tripping caused by accumulated earth leakage across several appliances
- Water ingress into outside lights, garden sockets or badly glanded armoured cable
- Loose neutral connections at sockets, causing intermittent dead circuits and heat damage
- Nail or screw damage to cables under floors or behind plasterboard after DIY or a carpet fitting
- Failing immersion heaters, showers and kitchen appliances that put a whole circuit out
- Deteriorated lighting circuit insulation in properties with original rubber or fabric cable
- Overloaded circuits with spurs added off spurs over the years
Test equipment and method
Fault finding uses calibrated multifunction test instruments, clamp meters for measuring live leakage current circuit by circuit without shutting a business down, and a socket-by-socket split of ring finals to isolate a section.
Leakage measurement is the tool that solves most nuisance tripping. Every appliance leaks a tiny amount to earth; a fridge, a boiler, a shower and an old washing machine together can push the total past the RCD's threshold, so nothing individually is 'faulty' but the circuit still trips. Measuring, rather than guessing, identifies the largest contributor.
Domestic and commercial differences
In a house, we can normally isolate a circuit for as long as the testing takes. In a shop, office or workshop that is rarely acceptable, so commercial fault finding leans on live leakage measurement and thermal checks first, with isolation scheduled out of hours if a full test is unavoidable.
Commercial work also brings three-phase supplies, distribution boards, phase imbalance and motor or refrigeration loads into the picture. Out-of-hours attendance is available so the diagnosis does not cost you a day's trading.
When fault finding turns into something bigger
Sometimes testing reveals the fault is a symptom of a wider problem: a lighting circuit whose insulation has failed along its whole length, or a board with no RCD protection at all. When that happens Jon will say so plainly and quote the larger job separately, with the option to make safe now and plan the rest later.
We will never inflate a repair into a rewire that the property does not need. If a £40 accessory fixes it, that is what you get told.
Reviews
What customers say
10/10
“Communications and arranging the date was excellent. Standard of work to a high standard and all to the agreed quotation.”
10/10
“Jon and his team turned up promptly as agreed, completed all works to a high standard and at a reasonable price.”
10/10
“Quickly turned up and safely dealt with cut cable to external garage. Great communication throughout.”
FAQs
Fault finding: common questions
How much does electrical fault finding cost?
£85 during standard hours (8:00am to 5:30pm), which covers the call-out and the first hour of fault-finding work. Evenings and weekends are charged at £140 per hour. Any repair is quoted for your approval before it is carried out.
How long does it take to find a fault?
Most faults are located within the first hour. Intermittent faults and buried cable damage can take longer, and Jon will tell you where things stand before the clock runs on.
Why does my RCD keep tripping?
Usually accumulated earth leakage from several appliances, water in an outside circuit, or a damaged cable. Measuring the leakage on each circuit identifies the culprit rather than guessing at it.
Can you fix the fault on the same visit?
In most cases yes, the van carries common accessories and cable. If a part needs ordering or the repair is extensive, you get a written price and a date.
Do you come out at night or at weekends?
Yes. Emergency call-outs are available 24/7 for dangerous faults, loss of power, burning smells and damaged cable, charged at £140 per hour outside standard hours.
Is the repair guaranteed?
All workmanship is guaranteed for twelve months, and JMO Electrical is NAPIT registered with £2 million public liability cover.
What should I do before you arrive?
If it is safe, unplug everything on the affected circuit and note exactly when the fault occurs. If you can smell burning or see damage, switch the circuit off at the board and call straight away.
Do I get paperwork afterwards?
Remedial work is certified, normally a Minor Electrical Installation Works Certificate, which landlords and insurers can rely on.
Which areas do you cover for fault finding?
Purley, Croydon, Caterham, Coulsdon, Sanderstead, Warlingham, Kenley, Sutton and London. Being Purley-based means short response times across CR postcodes.
Areas covered
Fault finding across Surrey and south London
Related services
New here? Start on the JMO Electrical home page, browse all services, or get in touch with Jon.
Stop resetting the breaker, get it diagnosed
£85 in standard hours covers the visit and the first hour of testing. You get a straight answer and a price before any repair goes ahead.