Hardwired combination smoke and carbon monoxide detectors have come a long way. They’re faster, smarter, and better integrated than ever before.
With dual-sensor technology, these alarms detect both smoke from fires and dangerous carbon monoxide leaks, providing essential protection in a single device.
But with so many options, which one should you trust to keep your home safe? We put the top models through their paces to help you decide.
Top Hardwired Combination Smoke & Carbon Monoxide Detectors
| Brand | Model | Backup Battery | Voice Alerts | Size (inches) | Weight (oz) | Price Range |
| Kidde | 9th Edition Series | Yes (10-year) / Yes (AA) / No | Yes (optional) / No | 5.6 x 5.6 x 1.8 | 7.7 | $35 – $55 |
| First Alert / BRK | SMICO100 | Yes (10-year) | No | 5.9 x 5.9 x 1.8 | 8.1 | $30 – $40 |
Best Overall: Kidde 9th Edition Series
Kidde is a household name for a reason. Their 9th Edition Series offers versatility and reliability, ensuring dual protection from fire and carbon monoxide hazards.
Three versions to choose from:
- Premium: 10-year battery backup + voice alerts.
- Mid-range: AA battery backup + no voice alerts.
- Basic: No backup battery + no voice alerts.
What’s New in the 9th Edition?
The 9th Edition introduces improved smoke and CO detection algorithms, reducing false alarms while enhancing sensitivity to real threats.
Additionally, the battery efficiency has been optimized, ensuring the full 10-year lifespan for models with sealed batteries.
The unit design has also been refined for easier installation and interconnectivity, allowing multiple alarms to trigger simultaneously for whole-home protection.
All models feature interconnectivity, meaning if one alarm goes off, the others in your home will too. The voice alert option is a valuable feature, clearly announcing whether there’s smoke or CO detected, avoiding confusion in an emergency.
✅ Pros: Flexible configurations, well-known brand, strong interconnectivity, dual protection, reduced false alarms.
❌ Cons: Higher-end models can be pricier.
Best Budget Pick: First Alert SMICO100
The SMICO100 replaces the older SC9120B model, bringing improved performance and compliance with the latest UL 217 8th edition standards.
This upgrade significantly reduces nuisance alarms caused by cooking while offering earlier fire detection.
Additionally, the unit comes with a quick-connect plug, simplifying installation without requiring rewiring.
✅ Pros: Enhanced fire detection, reduced false alarms, quick-connect installation.
❌ Cons: No voice alerts, slightly bulkier design.
First Alert vs. BRK: What’s the Difference?
Ever wonder why some alarms are labeled First Alert while others say BRK? They’re actually the same company. BRK is the commercial-grade brand, often used in contractor installations.
First Alert is the consumer-facing brand you’ll find in most stores. Functionally, they’re identical—just different labels for different markets.
Final Thoughts: Which One Should You Get?
- Want premium features and flexibility? Get the Kidde 9th Edition Series.
- Need an upgraded, budget-friendly option? The First Alert SMICO100 is the way to go.
Whichever you choose, install it correctly, test it regularly, and sleep easier knowing your home is protected from both fire and carbon monoxide dangers.