FireAngel SP500 Smoke Alarm: What It Does and How to Keep It Ready

The FireAngel SP500 is a mains powered smoke alarm that sounds at more than 85 dB at 3m and carries a 10 year warranty¹. For a household getting ready for emergencies, its job is simple and important: it gives you early warning of a fire at night or during a power cut, when you have least time to react. The maker's range also includes heat and carbon monoxide alarms, so the first thing to establish is which alarm you actually have².

Getting the most from it comes down to three things. Fit it where you will hear it, which means hallways, landings and inside or directly outside bedrooms, on every level of the home⁵. Test it regularly and know what its beeps mean, because a chirping alarm is telling you something rather than malfunctioning for no reason⁶. And keep the model code and FireAngel's support number to hand, so that if it faults you can get advice rather than leaving a dead alarm on the ceiling⁸.

FireAngel SP500: a smoke alarm for the home

The SP500 is a smoke alarm, not a heat alarm and not a carbon monoxide alarm². That distinction matters more than it sounds. A smoke alarm responds to smoke and is the right device for hallways, landings, living rooms and bedrooms, where a fire would produce smoke before it produced much heat. A heat alarm is for kitchens, garages and attics, where cooking and dust would set a smoke alarm off constantly. A carbon monoxide alarm is for rooms with a fuel-burning appliance. Fitting the wrong type in the wrong place either leaves you unprotected or leaves you with an alarm you keep silencing.

The SP500 is mains powered, running on AC 230V / 50Hz¹. That means it draws its power from the home's wiring rather than a battery you change, which suits a household that wants an alarm it does not have to think about. It also means it is only as reliable as the circuit it sits on. During a power cut the alarm will not have mains power, so it is worth knowing how your particular unit behaves and checking it once the power returns. If you want an alarm that keeps working through an outage without any wiring at all, a battery powered model is the alternative, and the choice between the two is set out in our guide to battery or mains smoke alarms.

The SP500 also has an end of life indication, a clear reminder to replace the alarm rather than a silent failure¹. Combined with the 10 year warranty, that gives a household a predictable replacement cycle: fit it, test it, and when it tells you it has reached the end of its life, replace it¹. The maker's wider range includes wireless interlinkable alarms and a wireless gateway, so a household extending its system later has somewhere to go, but the SP500 itself is a standalone smoke alarm¹⁰.

Model code FA4150BW and what the specifications tell you

The quick reference code FA4150BW identifies your alarm as the SP500, a mains powered smoke alarm¹. It is worth writing down and keeping with your household paperwork, because when an alarm starts misbehaving the first question any support line will ask is which model you have.

Two of these specifications bear directly on emergency planning. The first is the sound level: more than 85 dB at 3m is loud, roughly the level of a busy road or a power tool, and it is the figure that decides whether the alarm will wake you¹. The second is night sensing, which senses ambient light and reduces the brightness of the green power LED so it does not disturb sleep¹. That sounds like a small comfort feature, but it matters for preparedness: an alarm whose light keeps you awake is an alarm you unplug or move, and a moved alarm protects nothing.

The low battery warning is the one to learn. On a mains alarm it may rarely sound, but if it does it is telling you the backup has gone, and the maker's advice is to consult the manual if the alarm beeps when it is not being tested, because the battery could be running low or the alarm could be coming to the end of its life⁷. Our guide to why a smoke alarm keeps chirping covers the general causes.

Where a smoke alarm needs to be heard

A smoke alarm earns its place by being heard, and that is a question of position rather than specification. FireAngel's advice is that smoke alarms should be installed in hallways, landing areas, lounge areas where people gather, inside or directly outside bedrooms, and on each level of your home⁵. The reasoning is straightforward: fires start in living spaces and kitchens, people sleep in bedrooms, and the route between the two is the hallway and landing. An alarm in a closed-off spare room protects the spare room.

For a fuller system, the maker recommends a smoke alarm in the circulation space on each level of the home, the hallway and landing, as well as in living spaces and bedrooms, alongside heat alarms in the kitchen, garage and attic, with the alarms interlinked so that if one sounds they all sound¹¹. Interlinking is what turns a collection of alarms into a system: a fire in the kitchen sets off every alarm in the house, including the one outside your bedroom door. Our guide to interlinked alarms explains how linking works.

Position on the wall or ceiling matters too. For a mains powered alarm, the maker's guidance is to ensure the alarm is 300mm from the nearest wall and between 100mm and 300mm below the ceiling¹³. For a battery powered smoke alarm the maker gives 300mm from the nearest wall and between 150mm and 300mm below the ceiling¹¹. Lincolnshire's fire and rescue service puts the general rule plainly: make sure the alarm is in a location where you can hear it when asleep and at least 30cm away from walls and light fittings¹⁴. The SP500 can be fitted in living rooms, bedrooms, hallways, landings and dining rooms¹³.

What to do when the alarm sounds

If the SP500 sounds and there is no fire, the maker's reset sequence is worth knowing before you need it. Wait for the alarm to stop sounding; if it carries on, remove the alarm from its base plate⁶. Refit the battery or reconnect the power, then reattach the alarm to its base plate and press the test button to check the alarm is working⁶. If it carries on sounding, clean it gently with a vacuum cleaner and a soft brush attachment¹⁵.

For mains powered alarms the maker adds a useful check. Remove the alarm from the base plate, reattach it, then test it twice: if you hear three beeps it is now fitted correctly and the amber light should stop; if it does not sound, or keeps flashing amber or chirping, replace it, or contact customer support if it is under warranty¹⁶.

A real alarm is a different matter. Get everyone out, stay out, and call 999. Our guide to what to do if a fire starts in your house sets out the order of actions, and how to make a fire escape plan covers practising the route before you need it. If you cannot get out, what to do if you cannot escape a fire explains how to protect yourself while you wait.

Hearing it while asleep, and when someone cannot hear it

The SP500's night sensing dims the green power LED in low light so it does not disturb sleep¹, and its sound level of more than 85 dB at 3m is designed to wake a sleeping household¹. But sound is reduced by closed doors and by distance, which is why the maker's placement advice puts an alarm inside or directly outside each bedroom rather than relying on one alarm downstairs⁵.

For anyone who is deaf or hard of hearing, sound alone is not enough. Specialist smoke alarms use a vibrating pad placed under a mattress or pillow at night; when smoke is detected the pad vibrates and the strobe light flashes to alert the sleeper¹⁷. Fire Scotland's deaf awareness guidance describes this setup, and it is the arrangement to ask about if a member of your household would not wake to an audible alarm¹⁷. Our guide to smoke and CO alarms for deaf and hard of hearing people covers the options.

There is one reassurance worth knowing if you ever have to silence an alarm to clear smoke from burnt toast. The smoke alarm will still detect smoke during this time¹⁸. Silencing buys you quiet, not blindness, but it is not a substitute for finding out why the alarm sounded.

Support, warranty and checking for notices

The SP500 carries a 10 year warranty¹. If it faults, the maker's advice is to contact the FireAngel Customer Support Team if the alarm is under warranty, and otherwise to replace it⁶. FireAngel customer support can be reached on 0800 141 2561 or by email at technicalsupport@fireangeltech.com for issues with current smoke alarms⁹. Lincolnshire County Council, which fits FireAngel alarms in some homes, directs residents to the same number, 0800 141 2561, or to the FireAngel website for advice¹⁴. The maker's fax line is +44 (0)2476 693610¹⁹.

Before you call, have the model code FA4150BW to hand, so support can identify your alarm as the SP500¹. It lets support match your alarm to the right datasheet and tell you quickly whether the fault is a battery, an end of life indication or something else. If you are checking whether a notice applies to your alarm, check the maker's own support pages and any paperwork that came with it, and ask support directly if you are unsure. Our guide to how to check if an electrical product has been recalled sets out the general approach.

Fire and rescue services also offer home fire safety visits, which Staffordshire Fire and Rescue Service describes on its site, and these can help if you are unsure where alarms should go or how to test them⁹. If your alarm is faulty, Buckinghamshire Fire and Rescue Service has guidance on faulty smoke alarms and what to do about them¹⁸. For the wider picture of alarm types and how to choose between them, see our guide to smoke alarms, and for the maker's full range, the FireAngel page.