Emergency Light Won't Turn Off? Here's What That Means For Your System

TL;DR

• An emergency light that stays lit and won't turn off after mains power returns almost always points to a charging circuit, relay or self-test unit fault, not normal behaviour.

• Leaving it running constantly drains the battery faster and can leave the fitting with no charge left when a real power cut happens.

• Under the Regulatory Reform (Fire Safety) Order 2005, a stuck-on emergency light is a fault the Responsible Person must record and fix, not a quirk to monitor.

• Most causes trace back to a failed charging relay, a faulty self-test module, or the unit being wired as maintained instead of non-maintained.

• Report the fault immediately, log it in the fire safety logbook, and get a qualified engineer to inspect the fitting before your next scheduled test.

An emergency light that won't turn off usually means the charging circuit, relay or self-test unit inside the fitting has failed, not that the light is doing its job too well. If you've noticed a bulkhead or exit sign still glowing hours, or even days, after the power came back on, that's a fault worth acting on straight away, not something to leave until your next scheduled test.

This is a genuinely common issue for Responsible Persons carrying out routine walk-round checks between formal test dates. It's also one that's easy to dismiss, because the light is still working, just at the wrong time. Below we explain why it happens, what it means for your emergency lighting testing obligations, and what to do about it.

What Does It Mean When an Emergency Light Won't Turn Off?

An emergency light that won't turn off after mains power is restored is telling you that its internal switching circuit isn't behaving as designed. In normal operation, a non-maintained emergency light only illuminates during a genuine power failure or when triggered by a fire alarm signal, then switches off automatically once mains supply returns and the battery starts recharging.

If the light stays on continuously, one of three things is usually happening: the unit has lost the mains reference signal it needs to know power has returned, the relay that controls switching has failed in the closed position, or the fitting's self-test unit has flagged an internal fault and locked the light on as a warning. None of these are things to wait out. Each one needs an engineer to look at the fitting.

Is an Emergency Light That Won't Turn Off a Compliance Problem?

Yes. Under the Regulatory Reform (Fire Safety) Order 2005, the Responsible Person for a building must ensure emergency lighting is maintained in efficient working order, and a fitting stuck permanently on is evidence that it isn't. BS 5266-1, the British Standard covering emergency lighting design, installation and maintenance, expects faults like this to be identified, logged and rectified as part of routine servicing, not left to correct themselves.

A stuck-on light is also a red flag during a fire risk assessment. An assessor who finds a fitting running continuously outside of a test will treat it as a maintenance failure, because it points to an underlying fault that could mean the light fails completely when it's actually needed.

What Causes an Emergency Light to Get Stuck On?

Three faults account for most cases of an emergency light that won't turn off. Each has a different fix, so identifying which one you're dealing with matters.

Failed Charging Circuit or Relay

The most common cause is a failed relay or charging circuit inside the fitting. This relay is what switches the light off once it detects that mains power has returned. When it fails in the closed position, the light has no way of knowing the power is back, so it keeps running on battery, or on a mixture of battery and mains, until the battery is damaged or the unit fails completely.

Self-Test Unit Fault

Fittings with a self-test function run automatic diagnostic checks and use light patterns, usually a flashing or solid LED, to report their status. If the self-test module detects an internal fault, some models default to staying illuminated as a visible fault warning rather than switching off. In this case, the light being stuck on is the unit telling you something else has gone wrong.

Maintained vs Non-Maintained Fitting Confusion

Occasionally what looks like a fault is a mismatch between the fitting type and how it was installed. Maintained emergency lights are designed to stay on permanently, drawing from the mains, and only switch to battery during a power failure. If a non-maintained fitting was wired or configured as maintained by mistake, it will appear to be stuck on when it's actually behaving as configured, just not as intended for that location.

What Happens If You Ignore an Emergency Light That Won't Turn Off?

Leaving a stuck-on emergency light unresolved shortens the battery's life and increases the risk that the fitting has no charge left when a genuine power failure happens. Emergency light batteries are only rated to provide illumination for a set duration, typically one to three hours, and that rating assumes the battery has been charging and discharging normally. A battery kept in constant use through a stuck-on fault degrades faster than the manufacturer's test cycle assumes, so the fitting can fail well before its expected lifespan.

There's also a compliance cost. If the fault isn't logged and actioned, it will surface at the next scheduled test or fire risk assessment as an outstanding non-conformance, which reflects on the building's overall fire safety management rather than being treated as a one-off issue.

What Should You Do If Your Emergency Light Won't Turn Off?

Report the fault as soon as you notice it, log it in the fire safety logbook with the date and location, and isolate the fitting if it's overheating or showing signs of damage. Don't attempt to force the light off at the switch or consumer unit, because emergency fittings are designed to stay illuminated during exactly that kind of interruption, and doing so can mask the underlying fault rather than fix it.

The most reliable next step is to get a qualified engineer to inspect the fitting rather than waiting for your next scheduled test visit. They can test the charging circuit, check the self-test diagnostics, and confirm whether the fix is a relay replacement, a battery swap, or electrical remedial repairs to the wider circuit.

How Professional Emergency Lighting Testing Catches This Before It Becomes a Problem

Routine testing is designed to catch exactly this type of fault before it becomes a compliance failure or a safety risk. A monthly flick test confirms the light illuminates on demand and switches off correctly afterwards, while a full annual duration test, carried out in line with BS 5266-1, checks that the battery holds charge for its full rated period and that the switching circuit resets correctly once mains power returns.

Between scheduled visits, a light that won't turn off is one of the clearest early warning signs a building has. Reporting it promptly, rather than waiting for the next test date, is what keeps a minor relay fault from becoming a failed fitting, a battery replacement, or a fire risk assessment finding.

Frequently Asked Questions

Why is my emergency light staying on all the time?

It's usually caused by a failed charging relay, a self-test fault, or the unit being wired as maintained instead of non-maintained. In each case the fitting has lost its ability to switch off automatically once mains power is confirmed. An engineer needs to inspect the unit to confirm which fault is present.

Is it dangerous if an emergency light won't turn off?

It's not an immediate electrical hazard, but it is a fire safety risk. A stuck-on light drains its battery faster than normal, which can leave you with no working emergency lighting if a genuine power failure happens before the fault is fixed.

Can a stuck emergency light damage the battery?

Yes. Emergency lighting batteries are designed for a specific charge and discharge cycle, and constant illumination outside that cycle accelerates wear. Left unresolved, this can shorten the battery's working life significantly and lead to complete failure.

Can I fix a stuck emergency light myself?

You shouldn't attempt to fix it yourself. Emergency lighting circuits are part of your building's fire safety system, and incorrect intervention can mask the fault or create a bigger safety issue. A qualified engineer should diagnose and repair the fitting.

How often should emergency lighting be tested?

BS 5266-1 recommends a monthly flick test to confirm the light activates on demand, plus a full annual duration test to check the battery holds charge for its rated period. Faults like a stuck-on light should be reported and fixed as soon as they're noticed, not left until the next scheduled test.

What standard covers emergency lighting maintenance in the UK?

BS 5266-1 is the British Standard covering the design, installation and ongoing maintenance of emergency lighting. It works alongside the Regulatory Reform (Fire Safety) Order 2005, which places the legal duty to maintain emergency lighting on the Responsible Person.

Who is responsible for fixing faulty emergency lighting in a commercial building?

The Responsible Person, typically the building owner, employer or managing agent, is legally responsible for ensuring emergency lighting faults are identified and fixed. In practice, this usually means instructing a qualified electrical or fire safety contractor to carry out the repair.