Real alarm · Kidde · carbon monoxide
Kidde: Four short beeps, five seconds of silence, repeating
Kidde’s CO alarm pattern: the alarm may have sensed a dangerous level of carbon monoxide. Kidde adds that it can also be a nuisance alarm — but you only decide that after following its CO instruction.
- What you see
- No light named by the maker
- What you hear
- Full alarm, four beeps then a pause, repeating
Do this first: the maker’s emergency instruction
Carbon monoxide alarm
Kidde: a sounding CO alarm means carbon monoxide, which can be fatal. Press the TEST/RESET button, call 911 or your local fire department, and move at once to fresh air — outside or by an open door or window. Account for everyone, and do not go back in until emergency services have arrived, the home has been aired out and the fire department gives the all clear.
From What Should I Do When My Carbon Monoxide Alarm Sounds?.
Smoke alarm
Kidde: never ignore the alarm. First check for fire. If there is one, wake small children and leave at once by your escape plan — do not stop to dress or collect valuables; feel a door before opening it and use another exit if it is hot; stay low in smoke; meet at your meeting place; call the fire department from a neighbour’s house; do not go back in until the fire department says it is safe.
What Kidde says to do about this signal
- Follow Kidde’s CO instruction first (above).
- If the alarm sounds again within 24 hours, Kidde says to repeat the steps and call a qualified appliance technician to look for CO sources and check the alarm system, and to make sure no vehicle has been running in an attached garage or next to the house.
From Why Is My Carbon Monoxide Alarm Beeping or Chirping?. If your alarm’s pattern is not exactly this, check the manual for your model: Kidde models do not all use the same signals.
Other Kidde signals
Real alarm on other brands
The same state sounds and looks different on each make — which is why a chirp pattern cannot be read without the brand.
Sources
Every line on this page comes from Kidde’s own documents, read on the date shown. Nothing is taken from third-party code sites or other makes.
- Kidde: Why Is My Carbon Monoxide Alarm Beeping or Chirping? — Kidde CO alarms, US range (support article). www.kidde.com Checked 2026-09-29.
- Kidde: What to Do When Your Smoke Alarm Sounds — Kidde smoke alarms, US range (support article). www.kidde.com Checked 2026-09-29.
- Kidde: What Should I Do When My Carbon Monoxide Alarm Sounds? — Kidde CO and combination alarms, US range (support article). www.kidde.com Checked 2026-09-29.