Emergency light flashing red: what the status LED means

What does the status LED on an emergency light show?

A status LED is a small indicator on the housing of a self-contained emergency luminaire that shows the state of the mains supply, battery, lamp and self-test. It lets anyone see at a glance, without a meter, whether a luminaire is ready for use.

On luminaires with an automatic test system to EN 62034, the LED also reports the result of the function and duration tests. In installations with a central or group battery, the fault indication usually sits on the central unit, and the luminaires themselves often have no status LED of their own. For background on automatic testing, see self-testing emergency lights.

What do green, red and other colours mean?

There is no single colour code that every manufacturer follows, although many use a similar pattern. The table below shows typical meanings – it does not replace the datasheet for your luminaire.

Some manufacturers use the flashing pattern (fast, slow, number of pulses) to distinguish between battery, lamp and electronics faults. Others use bi-colour LEDs or only reveal the exact fault code via an app or a bus system.

What typically causes a red indication?

Most red indications come down to a handful of causes:

• Weak or failed battery: the battery can no longer reach the rated duration. This is the most common cause, especially in luminaires older than four to five years or mounted in warm locations. More in emergency light batteries.
• Failed lamp: the LED, or on older units the fluorescent tube, has failed. The luminaire would switch over in an emergency but give no light.
• Charging fault: the charging electronics are not working, the battery is disconnected or wrongly connected, or the luminaire loses its supply from time to time – for example because it has been wired to a switched circuit.
• Failed test: the automatic function or duration test was not passed. The luminaire keeps showing the fault until it has been rectified and a new test has been passed.
• Test overdue or aborted: a test could not be completed, for instance because the mains failed during the test or the battery was not yet fully charged.
• After battery replacement or new installation: many luminaires initially show a fault after power-up until the new battery is fully charged. This clears once charging is complete.

What should you do now?

A red status LED is a defect in a life-safety system. It should not be left for weeks.

Immediate steps

• Record the location of the luminaire, the date and the exact indication (colour, flashing pattern) in the logbook.
• Find the datasheet or instructions and identify what the indication means.
• Check whether there has recently been a power cut, a battery change or electrical work. A charging cycle may then be the cause.
• Check whether other luminaires in the same area or circuit are affected. Several simultaneous faults point to a supply problem.
• Ask a qualified electrician or your maintenance contractor to diagnose and fix the fault.

Do not open the luminaire yourself unless you are a qualified electrician. Work on emergency luminaires is work on an electrical installation; who may do what is covered in who may test emergency lighting.

Interim measures until the repair

If a luminaire on an escape route or at an exit fails, a dark spot can appear in an emergency. Depending on its location and importance, possible interim measures include informing staff, a tested portable battery-powered light as a stopgap, shorter check intervals or, where several luminaires have failed, consulting the person responsible for fire safety. The appropriate measure follows from your risk assessment.

Who should you call?

Your first point of contact is the maintenance contractor or electrician who looks after the installation. If the luminaire is under a manufacturer's warranty, check the terms first: batteries and lamps are sometimes treated separately. Responsibility for having the defect rectified usually remains with the operator – see operator duties and liability.

What is the risk if you do nothing?

A red indication means the luminaire has detected a fault in itself. In an emergency – a power cut, fire or short circuit – it may stay dark, or switch off after a few minutes because the battery is flat. That is exactly the moment it is needed to make escape routes and exits visible.

There is also the question of evidence. During an inspection by the authorities, fire service or an expert, a steady red LED is noticed immediately. How testing and records fit together is covered in emergency lighting testing intervals.

How can red indications be prevented?

Faults cannot be ruled out entirely, but they can be detected early and fixed on a planned basis:

• Keep to the test intervals: a monthly function test and an annual test over the full rated duration, as set out in EN 50172 and in national rules such as DIN VDE V 0108-100-1 in Germany.
• Replace batteries proactively: not when the LED turns red, but at the interval specified by the manufacturer or as soon as the annual test becomes marginal.
• Use self-testing luminaires: luminaires with automatic tests to EN 62034 report faults immediately and log the results.
• Check status LEDs on every walk-round: a quick glance is enough if everyone involved knows what green and red mean.
• Mind the ambient temperature: luminaires in very warm locations, such as under roofs or near heat sources, age faster.

On NOTLUX Series 19 luminaires, the function and duration tests run automatically, and the results can be read via Bluetooth and an app and exported as a test report. So alongside the status LED, the specific fault is recorded in the digital logbook.