The Secret Behind the END on Carbon Monoxide Detectors

If your digital carbon monoxide alarm displays "END" on its display, it means that the alarm has reached the end of its life and needs to be replaced. The alarm will also chirp 5 times per minute to let you know it's time for replacement. The beeping sound will only stop when the unit is switched off completely.
The alarm will indicate end of life seven or ten years after initial power. You'll know that it is an end-of-life warning and not a low battery warning because replacing the batteries will not stop the chirp.
Many carbon monoxide and smoke detectors come with a "Hush" feature, which will stop the beeping for 72 hours. To silence the beeping, press and hold the "Hush" or "Test" button.
What is the end of life warning on my CO alarm?

[@Megabean]

I got one in the basement near the water heater and furnace, one in the living room and one in the kitchen. Never had false positive issues in the kitchen, I keep it near our gas stove too. But I always open the kitchen window when cooking. My landlord didn't put a proper fume extractor into our kitchen. Its just the kind with a filter in it, it freaks me out.

[@HomeRapidRepair]

Ok. Sounds like you got it covered though. Thanks for sharing 😊

[@davidgrisez]

Last night I got up to go to the bathroom. And when I got back in bed the Carbon Monoxide detector in my bedroom, which is the same model as shown in this video began chirping just like this video shows. My carbon monoxide detector displayed the word "END". I had to get up out of bed and unplug the carbon monoxide detector and remove its battery. My condominium that I live in is heated and cooled with a single stage heat pump. Also for cooking I rarely use the stove. I primarily use the microwave oven. As a result it is close to impossible for there to ever be build up of carbon monoxide in my condominium. This is because it requires combustion to make carbon monoxide.

[@HomeRapidRepair]

I think all your points are true and fair. The best recommendation is if you have any gas appliance at all, which you do with the range. You should still have a carbon monoxide detector. But you are at very low risk. It also has protected people when they do something stupid such as run a gas, powered generator inside or warm up the car inside attached garage…

[@ranger178]

I am throwing mine out and never buying another stupid thing waking me up in middle of night to tell me it is ten years old rather than just have display telling me time to replace it

[@HomeRapidRepair]

Hey I hear your pain points. I get it. I personally know a family who lost a son to carbon monoxide poisoning and a $20 CO detector would have saved his life for sure. Stay safe out there my friend 😊

[@ranger178]

I have same kind in basement boiler room must be 20 some years old and it still works then i buy a new one with natural gas and carbon monoxide for kitchen and it has June of 2015 date of manufacture and it alarms to tell me to go buy a new one I do look at the display once in a while it could have just said please replace with new one and i would replace it but it would be nice to put old one someplace like garage where it would go off if i ran generator or snowblower in there but nice to know how much CO there is in there@@HomeRapidRepair

[@ggsipaper]

I would never see the display to replace it. The beeping is the only thing that alerted me. I was luckier than you and mine went off sometime around 11 AM.