First Alert SMCO210

First Alert SMCO210 10-Year Sealed Battery Combination Smoke & Carbon Monoxide Alarm Instruction Manual

Model: SMCO210 | Brand: First Alert

1. Introduction

The First Alert SMCO210 is a 10-Year Sealed Battery Combination Smoke & Carbon Monoxide Alarm featuring a slim profile design. This device utilizes Precision Detection advanced sensing technology, complying with current industry standards to minimize nuisance alarms from cooking while providing early warning for both fire and carbon monoxide (CO) hazards. The integrated 10-year sealed battery eliminates the need for battery replacements and prevents low battery chirps for the alarm's lifespan.

First Alert SMCO210 10-Year Battery 2-in-1 Smoke & CO Alarm with Slim Profile Design

Figure 1: First Alert SMCO210 10-Year Battery 2-in-1 Smoke & CO Alarm with Slim Profile Design. This image highlights the compact and dual-functionality of the alarm.

2. Setup

2.1 Unpacking and Initial Inspection

Carefully remove the alarm and its components from the packaging. Inspect the unit for any signs of damage. The package includes the SMCO210 alarm, a mounting bracket, and hardware (screws and anchors).

First Alert SMCO210 Smoke & CO Alarm with mounting bracket and hardware

Figure 2: Contents of the First Alert SMCO210 package, showing the alarm unit, mounting bracket, screws, and anchors.

2.2 Recommended Placement

For optimal safety, install combination smoke and carbon monoxide alarms on every level of your home and in every bedroom. Ensure alarms are placed away from cooking appliances to minimize nuisance alarms, but close enough to detect actual fire hazards. Avoid placing in areas with high humidity or extreme temperatures.

Diagram showing recommended placement of smoke and carbon monoxide alarms in a multi-story house

Figure 3: A visual guide illustrating the recommended locations for smoke and carbon monoxide alarms throughout a typical home, including bedrooms, hallways, living rooms, kitchens, and basements.

2.3 Mounting the Alarm

  1. Select a suitable location on a ceiling or wall, following the recommended placement guidelines.
  2. Use the provided mounting bracket as a template to mark the screw holes. The bracket is designed with multiple slots to accommodate various existing screw hole patterns, eliminating the need to drill new holes if replacing an older unit.
  3. Drill pilot holes if necessary and insert the plastic anchors.
  4. Secure the mounting bracket to the ceiling or wall using the provided screws.
  5. Align the alarm with the mounting bracket and turn clockwise until it locks securely into place. This action activates the alarm's sealed 10-year battery.
Man installing a First Alert SMCO210 alarm on a ceiling

Figure 4: A person installing the First Alert SMCO210 alarm on a ceiling, demonstrating the ease of mounting.

Video 1: SMCO210 Summary Video. This video provides a brief overview of the product's features and installation process.

3. Operation

3.1 Activation

The alarm activates automatically when twisted onto the mounting bracket. A green LED light will flash periodically to indicate normal operation.

3.2 Test/Silence Button

Press and hold the 'TEST/SILENCE' button located on the front of the alarm to test its functionality. The alarm will emit a series of loud beeps, indicating that the smoke and CO sensors are working correctly. This button can also be used to silence nuisance alarms for a short period.

Man pressing the test button on a First Alert SMCO210 alarm

Figure 5: A person testing the alarm by pressing the central button, demonstrating a routine check for functionality.

3.3 Alarm Signals

  • Smoke Alarm: Three loud beeps followed by a pause, then three more beeps. The red LED will flash rapidly.
  • Carbon Monoxide Alarm: Four loud beeps followed by a pause, then four more beeps. The red LED will flash rapidly.
  • Low Battery Warning: A single chirp every minute. This indicates the sealed 10-year battery is nearing its end of life.
  • End-of-Life Warning: Two chirps every 30 seconds. This indicates the alarm unit needs to be replaced.

4. Maintenance

4.1 Regular Testing

Test your alarm weekly by pressing the 'TEST/SILENCE' button. This ensures the electronic circuitry, alarm, and battery are functioning correctly.

4.2 Cleaning

Clean your alarm at least once a month to remove dust and debris. Use a soft brush attachment on your vacuum cleaner to gently vacuum the cover of the alarm. Do not use water, cleaners, or solvents as these may damage the unit.

4.3 End-of-Life Replacement

The SMCO210 alarm has a sealed 10-year battery and is designed to last for 10 years from the date of installation. After 10 years, the unit will signal an end-of-life warning (two chirps every 30 seconds), indicating it's time to replace the entire alarm unit. Do not attempt to replace the internal battery.

Woman holding a First Alert SMCO210 alarm with text 'Replace alarms at least every 10 years'

Figure 6: A visual reminder to replace the alarm unit after 10 years of service.

5. Troubleshooting

5.1 Nuisance Alarms

If the alarm sounds due to cooking smoke or steam, press the 'TEST/SILENCE' button to temporarily silence it. Ensure proper ventilation in cooking areas. If nuisance alarms persist, review the placement guidelines to ensure the alarm is not too close to sources of steam or smoke.

5.2 Chirping Sounds

  • One Chirp per minute: Indicates a low battery. The sealed battery is nearing the end of its 10-year life. Replace the entire alarm unit.
  • Two Chirps every 30 seconds: Indicates the alarm has reached its end-of-life. Replace the entire alarm unit.
  • Intermittent Chirps: May indicate a malfunction or a need for cleaning. Clean the alarm as per maintenance instructions. If chirping continues, replace the unit.

5.3 Alarm Does Not Sound During Test

Ensure the alarm is properly twisted onto its mounting bracket and fully activated. If the alarm still does not sound, the unit may be defective and should be replaced immediately.

6. Specifications

FeatureDetail
BrandFirst Alert
Model NumberSMCO210
Power Source10-Year Sealed Lithium Battery (included)
Alarm TypeCombination Smoke & Carbon Monoxide
Sensor TypePhotoelectric
Product Dimensions5.67"D x 5.67"W x 1"H
Item Weight6.4 ounces
Operating Humidity10-95% RH
ColorWhite
ManufacturerResideo
UPC029054022233

7. Warranty & Support

7.1 Warranty Information

This First Alert SMCO210 alarm comes with a manufacturer's warranty. For detailed information regarding the warranty period and terms, please refer to the documentation included with your product or visit the official First Alert website.

7.2 Customer Support

For technical assistance, troubleshooting, or general inquiries, please contact First Alert customer support. Contact information can typically be found in the product packaging or on the official First Alert website: www.firstalert.com.

© 2026 First Alert. All rights reserved. This manual is for informational purposes only.

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