Manufacturer guidance. This testing demonstration is from Aico's own YouTube channel. Aico are a UK fire safety manufacturer based in Oswestry, and their interlinked alarm systems are among the most common mains-wired setups in UK homes. If you have a different brand, the button layout will differ but the testing principle is the same.
1. Identify the alarm types in your home
Walk through every room and note what is fitted. Smoke alarms -- optical or ionisation -- belong in hallways and on landings. Heat alarms belong in the kitchen, where cooking fumes would cause a smoke alarm to nuisance-trip constantly. Carbon monoxide alarms are a separate device entirely and covered in a different guide.
Check whether the alarms are hardwired and interlinked (a cable runs between them, often through the ceiling void) or radio-interlinked (they communicate wirelessly). Aico do both. The test process is the same either way.
2. Test each alarm individually
Stand below the alarm and press and hold the test button for approximately five seconds. A correctly functioning alarm will sound at full volume -- typically 85 dB at three metres -- and the status LED will flash. Release the button and the alarm should silence within a few seconds.
If the alarm sounds but immediately cuts out, the battery or mains supply may be marginal. If it does not sound at all, the unit has failed.
3. Check the interlink response
When you trigger one alarm, every interlinked alarm in the house should sound within a few seconds, even if they are on a different floor. Walk through the property after triggering the first alarm to confirm all units are responding. A unit that fails to sound when triggered remotely has a broken interlink connection, whether that is a wiring fault or a radio pairing issue.
Note which unit you triggered to start, because if you need to silence the alarm remotely, you press the hush button on the unit that started it, not on the units that responded.
4. Test the hush function
The hush button temporarily reduces sensitivity for a set period (usually 10 minutes on Aico units). It is designed to silence a nuisance alarm from cooking without disabling the system. To test it, trigger the alarm normally, then press the hush button briefly. The sounder should drop to a lower level or stop. At the end of the hush period it should return to full sensitivity automatically.
Do not confuse the hush button with the test button. On many units they are the same physical button but with different press durations.
5. Clean and inspect each unit
Dust and insect ingress are the most common causes of nuisance trips and reduced sensor performance. Use a vacuum cleaner with a soft brush attachment to clean the sensor grille on each unit. Do not spray any cleaning product into the sensor chamber.
Inspect the cover for yellowing (a sign of age), cracks or any gaps where insects could enter. Check that the mounting plate is still secure to the ceiling. On battery backup units, note the date on any batteries and replace if they are more than three years old.
6. Replace any unit that fails
A smoke or heat alarm that does not respond to the test button must be replaced that day, not added to a list. Most manufacturers stamp a replacement date inside the cover -- the standard recommendation is 10 years. If the date is past or missing, replace the unit regardless.
When replacing a unit in an interlinked system, make sure the replacement is from the same range or is confirmed to interlink with your existing units. Mixing brands that are not cross-compatible will break the interlink.
When to call us
If you are not sure your alarm system meets BS 5839-6 for position and grade, or the interlink has stopped working, Richard can check it as part of an EICR inspection or a call-out in Sandwich and east Kent.
Want your alarm system checked in Sandwich?
If you are not confident the alarms are positioned correctly or the interlink is working, Richard can inspect and test the system on a visit.
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