Troubleshooting smoke detectors that beep

How to fix beeping smoke alarms

One of the most common problems customers ask for help with smoke alarms is intermittent beeping noises. So if your detector is driving you mad because it keeps beeping; (which sounds like a bird chirping) here are some things you can check:

  • Mains failure – your detector has lost its power supply. Most models display a green light when all is well.

Some smoke alarms have their own circuit from the consumer unit. So if the power was removed you wouldn’t know straight away because the battery back-up would step in. Some smoke detectors are wired in with the lighting circuit so in the event of power failure you would likely know straight away as the lights wouldn’t work either.

  • A faulty battery. Some models have replaceable batteries. Manufacturers usually recommend they are replaced every twelve months. If your detector has replaceable batteries; you can replace them and see if the beeping noise stops. Some models have sealed, lithuim batteries which cannot be replaced. They charge from the mains power and more reliable than the alkaline models.
  • Cleaning is necessary. Regular cleaning will help your detector work as intended and reduce false alarms. With the power switched off; use the thin attachment and vacuum the vents. You can wipe the cover with a damp cloth. Don’t forget to switch the mains back on and test the unit.
  • Hush (or silence) feature is active. In the event of a false alarm; users can silence the alarm whilst the room is cleared (usually for around ten minutes).
  • The right alarm. Are you sure the beeping is coming from the detector you are checking? Sound travels so if possible get others to help by standing close to the detectors on a step ladder to ensure you have found the one that is beeping.
  • Remove it. If the detector head has been removed along with the battery and you can still hear beeping then its somewhere else. The AICO models i install do not have sounders inside the base unit fixed to the ceiling.
  • Faulty. Smoke alarms can develop faults. Inside the warranty period they can be repaired or replaced by the manufacturer. Outside this time they will need to be replaced.
  • Expired. Most are made to last ten years. Has your detector expired?

Other reasons smoke detectors beep

I was called out one morning by a customer in the City Centre who installed his own smoke alarms the previous evening. He took the supply from nearby light fixtures which is a pretty standard after-market method of installation. Everything was fine initially, but he couldn’t work out why they started chirping not long after he went to bed. In older parts of Cardiff the way lights used to be wired often meant the light fitting only had what electricians refer to as “the switched live”. That is the wire that is live when the switch for the light is in the on position. Smoke alarms need a constant power supply to work properly. The detector was working correctly. It was beeping because the mains supply has been lost and needed new wiring to get working correctly. The customer hired me to install Aico detectors and the necessary wiring in his city centre apartment and all was well.