Quick answer
An amber or yellow fault light means the panel has found a problem with the system itself, most often a dirty detector, a low standby battery, an interruption to the mains supply or a break in a wiring loop, and the system may not give full protection until it is put right.
A fault is a warning, not an alarm. It should always be looked into promptly, and it is worth acting on the same day.
Reading the indicators
- Red, with a sounder. A fire condition. Evacuate and follow your fire procedure.
- Amber or yellow, general fault. The system has a problem with itself. The panel will usually name the zone or device.
- Amber, power or supply fault. Either the mains supply or the standby batteries.
- Amber, disablement. Somebody has deliberately isolated a zone, a device or the sounders, often during building work, and it has not been put back.
- Amber, test. The panel is in a test mode. It should not be left there.
Note the exact wording and any zone number before you silence anything. Panels vary, so your own panel’s instructions are the reference, and the log book should be beside the panel.
Common reasons for a fault
A dirty or dusty detector. Smoke detectors are looking for particles in the air, and dust, insects, cobwebs, aerosols or building work will eventually make one report that it is contaminated. This is the most common single cause, and it usually names one device.
A low or failing standby battery. Panels hold batteries so the system keeps working through a power cut. Those batteries have a service life, and a battery fault often appears a few hours after a long power cut, or simply because the batteries are due for replacement.
A mains interruption. A tripped breaker, a switched off fused spur or a power cut leaves the panel on batteries and showing a supply fault.
An open circuit or short on a loop. A cable damaged during other building work, a device removed and not replaced, or a connection that has worked loose in a terminal.
A call point or device fault. A manual call point that has been operated and not reset, or a device that has failed and is no longer answering the panel.
What you can do safely
- Write down the message and the zone shown on the panel.
- Silence the fault buzzer using the instructions for your panel, so the noise does not push anybody into unplugging it.
- Check the mains supply to the panel: the fused spur switch, its neon, and the relevant breaker.
- If the panel names a detector you can reach safely from the ground, gently dust it with a soft brush or a vacuum nozzle held nearby.
- Check whether a call point has been operated, and reset it with the correct key or tool if it has.
- Try a reset at the panel. If the fault returns immediately, leave it and call for an engineer.
Do not power the panel down or disconnect its batteries to stop the noise, and do not disable a zone to make a fault go away. Both leave the building without the protection the system exists to give, and a disabled zone is easy to forget.
The standards behind your system
Fire detection and alarm systems in non-domestic buildings are normally designed, installed and maintained to BS 5839-1, and systems in dwellings to BS 5839-6. BS 5839-1 recommends a weekly user test of one manual call point, a written record of each test and fault in the log book, and periodic inspection and servicing by a competent person, commonly at intervals not exceeding six months. Keeping the log book up to date is part of the standard, and it is also the record you will be asked for.
When to call an engineer
Call us if the fault returns after a reset, if the panel reports a battery or supply fault that does not clear once mains power is restored, if a loop or device fault is shown, or if the fault names a device you cannot reach safely. A fire alarm showing a fault is not giving you full cover. Advanced Overwatch installs and maintains fire alarm systems across Northern Ireland, with the work carried out by qualified engineers. Call 028 7087 8077 and we will help you get it back to normal.
Related reading
- Service page: Fire alarm servicing and maintenance
- Related guide: How often should fire extinguishers be serviced?
- All of our guides: Knowledge Base