why does mine chirp intertmittently

If it is a 9 volt battery, it may not be seated correctly. See the video on the first alert website, and be prepared to do some hard pushing to get the 9V battery to engage. I had 3 9V units, and 2 of the 3 seemingly required excessive pressure to get the batteries to engage. When I first thought I had the batteries installed by just closing the door, the unit chirped until I got the batteries shoved on hard.

Will the unit work without a bettery in it?

I'm putting these units into rentals. Will this work without a battery in it? If the battery runs low, the tenants usually take the whole unit down rather than change the battery - rendering the whole concept useless. This is the reason I would like to invest in "plug-in" units. However, somewhere it said it will chirp if battery is missing. Please clarify. I need a unit that will be effective, even without a battery installed.

Does the monitor plug directly into the wall socket or is there an electric cord?

No cord. The alarm plugs in directly to the outlet.

At what level of co does this alarm sound? Thank you for your time.

The following info is verbatim from the instructions that came with the unit: Actuation of the Alarm indicates the presence of carbon monoxide which can kill you. In other words, when our CO Alarm sounds, you must not ignore it! The following is not verbatim but a summary of regulatory requirements. Levels of CO that cause an alarm: at 400 ppm of CO, it must alarm between 4 and 15 minutes; at 150 ppm of CO, it must alarm between 10 and 50 minutes; at 70 ppm of CO, it must alarm between 60 and 120 minutes. The unit is designed not to alarm when expose to a constant level of 30 ppm for 30 days. Hope this has answered your question....from housewife1.

First Alert Carbon Monoxide Detector Alarm | Plug-In with Battery Backup, CO605

First Alert Carbon Monoxide Detector Alarm | Plug-In with Battery Backup, CO605

Product ID: 289635423

Details

Brand
First Alert
Colour
white
Item weight
4.2 Ounces
Power source
Battery
Style
Compact

📊Backlit digital display with peak memory

🔋Battery backup for power outage safety

🔌Detachable plug for flexible mounting

Description

🚨 Stay ahead of danger with smart, flexible CO protection!

CLEAR INTUITIVE - Backlit digital display shows real-time CO levels and peak readings at a glance.
FLEXIBLE PLACEMENT - Detachable 6-foot power cord lets you mount at eye level for optimal monitoring.
UNMATCHED ACCURACY - Electrochemical sensor delivers precise CO detection for your peace of mind.
POWER WHEN YOU NEED IT - Dual power source with plug-in convenience plus battery backup ensures 24/7 protection.
USER FRIENDLY MAINTENANCE - Front-access battery door and mute/test button simplify upkeep and nuisance alarm control.

The First Alert CO605 is a plug-in carbon monoxide detector featuring an advanced electrochemical sensor for high accuracy. It includes a detachable power cord for versatile placement, a backlit digital display with peak level memory, and a battery backup to maintain operation during outages. Designed for easy maintenance and reliable 85dB alerts, it meets UL safety standards and offers 7 years of limited protection.

Specifications

ASIN	B000ND74XA
Alarm	Audible
Brand	First Alert
Built-In Media	Alarm, Battery
Color	white
Customer Reviews	4.7 4.7 out of 5 stars (27,288)
Enclosure Material	Plastic
Global Trade Identification Number	00029054000682
Item Type Name	CO Alarm
Item Weight	4.2 Ounces
Manufacturer	First Alert
Model Number	CO606
Power Source	Battery Powered
Product Style	Compact
Sensor Type	Electrochemical
UPC	029054000682
Unit Count	1.0 Count

Reviews

J**E

These are great monitors. They came highly recommended by my fire department nearby. This 3pk. buy worked great because of the size of home, the people I was buying it for.

13.12.2025

C**S

Review: Excellent Review Excellent Report with no problems! Al Thomas, MD

13.02.2026

D**S

utterly useless, sold on amazon as a plug in alarm suitable for U.K market, plug in not compatible with british wall sockets. needs returning to the U.S.A.

16.12.2014

S**S

The inclusion of a 9V battery right out of the box is a thoughtful touch. It gives me peace of mind knowing that the detector is ready to go, and the added battery backup ensures continuous protection even during power outages. I tested the detector when it arrived, and everything checked out. The ease of setup and the immediate functionality straight out of the box impressed me. The clear instructions provided made the installation process a breeze. As a consumer, the First Alert brand has always been synonymous with reliability and trust. This CO detector is no exception. It reinforces my confidence in the brand, and I appreciate the commitment to delivering high-quality products that prioritize safety... at a reasonable price. The white design seamlessly blends with my home decor, making it unobtrusive. The compact size ensures it doesn't take up much space. In summary, the First Alert CO605 Carbon Monoxide Detector is a stellar product that offers peace of mind, reliability, and ease of use. I highly recommend it to anyone in need of a top-notch carbon monoxide detector. Five stars – well deserved!

24.01.2024

A**R

It arrived ahead of estimated arrival. It was well packaged and protected. This item comes very highly rated and hasn't disappointed yet.eg false alarms; dead batteries. Peace of mind at a fair price.

25.05.2019

Common Questions

Are the products genuine and authentic?+

Yes, all products are sourced directly from authorized retailers in the US, UK, UAE and India. We maintain strict quality control processes and verify each product before shipping. All items come with applicable manufacturer warranties and are covered by our standard return policy.

How long does delivery take and is it reliable?+

Delivery times vary by destination country, typically ranging from 3-9 business days. Each order is fully trackable through our system. We handle all customs clearance and use reliable courier partners for last-mile delivery. You'll receive regular updates about your order status via email and our app.

What is Desertcart? Is it safe to order from?+

Desertcart is an international e-commerce platform operating since 2014. We securely process thousands of orders globally each day. Every product goes through our quality verification process before delivery, and we provide end-to-end order tracking, 24/7 customer support, and a comprehensive returns policy to ensure a safe shopping experience.

How is product pricing calculated?+

Our prices include the product cost, international shipping, import duties, customs clearance, and local delivery charges. We handle all customs and import procedures, ensuring there are no hidden fees upon delivery. PRO members receive additional benefits including free shipping.

Trustpilot

TrustScore 4.5 | 7,300+ reviews

Neha S.

Excellent communication throughout the order process. Product is perfect.

2 weeks ago

Vikram D.

The MOLLE sheath is of exceptional quality. Very happy with my purchase.

2 weeks ago

View all Trustpilot reviews

Shop Global, Save with Desertcart

Value for Money

Competitive prices on a vast range of products

Shop Globally

Serving millions of shoppers across more than 100 countries

Enhanced Protection

Trusted payment options loved by worldwide shoppers

Customer Assurance

Trusted payment options loved by worldwide shoppers.

Desertcart App

Shop on the go, anytime, anywhere.

Trustpilot

TrustScore 4.5 | 7,300+ reviews

Yusuf A.

Fantastic experience overall. Will recommend to friends and family.

1 month ago

Neha S.

Excellent communication throughout the order process. Product is perfect.

2 weeks ago

View all Trustpilot reviews