How to Tell If Your Electrics Are Safe: Warning Signs to Watch For

Electrical faults are responsible for around 20,000 house fires every year in the UK. The frustrating truth is that most of these are preventable — the warning signs were there, but homeowners either did not know what to look for or assumed everything was fine because the lights came on. This guide helps you spot the signs of unsafe electrics in 2026 and tells you exactly what to do about them.

Visual Signs of Unsafe Electrics

You do not need to be an electrician to spot many warning signs. The following are all red flags that warrant immediate investigation by a qualified professional.

Discoloured or scorched sockets and switches

Brown or black discolouration around socket faceplates, switch covers, or the consumer unit is a clear sign of overheating or arcing — where electricity jumps a gap, producing intense heat. Even if there is no obvious burning smell, do not ignore scorch marks. Switch off the affected circuit and call a registered electrician the same day.

Burning smell with no obvious source

A faint burning smell that comes and goes — particularly near the consumer unit, sockets, or light fittings — is serious. Electrical fires often start inside walls and ceilings before any visible flame appears. A smell of burning plastic is especially alarming. Do not try to locate it yourself by removing faceplates — call an electrician.

Buzzing or crackling sounds

Electrical installations should be silent. If you can hear buzzing, crackling, or humming from sockets, switches, or the consumer unit, it indicates loose connections, overloaded wiring, or failing components. This is not a normal feature of old houses — it is a fault.

Flickering or dimming lights

Occasional flicker when a large appliance starts up (like a washing machine or fridge compressor) can be normal. Persistent flickering in one room or across the house, dimming without explanation, or lights that go out briefly when other things switch on, all point to wiring issues. This is often the first sign that a rewire is needed — see our guide on when to rewire your house for the full picture.

Old consumer unit with no RCDs

If your consumer unit (fuse box) contains rewirable wire fuses rather than modern circuit breakers, or has no Residual Current Devices (RCDs), it does not provide the level of protection required under current standards. Pre-2016 boards without RCD protection are a significant safety concern. Replacement costs and options are covered in our consumer unit replacement cost guide.

Hot plugs or sockets

Sockets and plugs should feel cool to the touch under normal use. If they feel warm or hot, there is either an overloaded circuit or a poor connection causing resistance heating. This is a fire risk. Switch off and investigate.

Visible old wiring (rubber-insulated, lead-sheathed)

If you can see wiring in the loft, under floorboards, or in a cupboard that looks black, brown, white with fabric braiding, or has a rubber rather than plastic outer sheath, this is pre-1970s wiring. Rubber insulation becomes brittle and cracks with age. This is a very high fire risk and should be assessed immediately.

What an EICR Checks

The only way to definitively assess the safety of your electrical installation is an Electrical Installation Condition Report (EICR). A registered electrician will inspect and test all fixed wiring, consumer unit, earthing and bonding, sockets, switches, and light fittings. For a full explanation of the process and what the codes mean, read our dedicated guide: What is an EICR and when do you need one?

The EICR tests things that are impossible to see without equipment — insulation resistance, earth continuity, polarity, and loop impedance. A visual check of your sockets and fuse box is useful, but it will not tell you whether the wiring inside your walls is deteriorating.

When Should You Book an EICR?

The current guidance from NICEIC and the IET recommends an EICR:

• Every 10 years for owner-occupied homes
• Every 5 years for rental properties (legally required for landlords)
• On change of occupancy — buying a new home
• Immediately if you notice any of the warning signs above
• If the property has not had an EICR in the past 10 years (or ever)

Common Faults Found During EICRs

Based on data from NICEIC and NAPIT, these are the most common issues electricians find when they inspect older UK homes:

• Missing or inadequate RCD protection — The single most common finding in homes with pre-2008 installations
• Deteriorated cable insulation — Brittle rubber crumbling away from conductors in loft and sub-floor spaces
• Missing earth connections — Many older homes have incomplete or missing bonding to gas and water pipes
• Undersized cables — DIY additions using cable that cannot handle the load of modern appliances
• Overloaded circuits — Too many sockets and appliances on a circuit designed for fewer loads
• Non-compliant bathroom wiring — Light pull cords replaced with wall switches, shaver sockets in wrong zones, heaters without proper protection

Many of these faults are invisible without testing equipment. A home that appears perfectly normal can have serious hidden faults. If your home is over 25 years old and has never had an EICR, booking one is the single most important thing you can do for your family's safety. Use our guide to finding a trustworthy electrician to make sure you hire someone properly qualified.

Frequently Asked Questions