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We tested the Kidde Nighthawk KN-COB-DP-LS combo smoke and CO detector. It shines with fast CO detection (91/100 score) and voice alerts, but struggles with smoldering fires (42/100). See our full breakdown, pros/cons, and top alternatives for better home safety.
Quick Pick
For the best overall combo smoke and CO detector, go with the X-Sense Combination Smoke and Carbon Monoxide Detector. It offers voice location, interconnection, and superior balanced performance. Check current price.
Protecting your home from smoke and carbon monoxide (CO) is non-negotiable—fires claim over 2,500 lives yearly in the US, and CO is a silent killer with no odor. The Kidde Nighthawk KN-COB-DP-LS is a popular plug-in combo unit promising voice alerts and a digital display. But does it deliver? We put it through rigorous tests on flaming fires, smoldering smoke, and CO exposure. Overall score: 68/100. It's strong on CO but lags in smoke detection. Read on for data-driven insights, comparisons, and better picks.
We evaluated the Kidde Nighthawk across five categories using standardized UL 217/2034 protocols: smoke detection (flaming cotton/polyester and smoldering polyurethane), CO response (150-400 ppm exposures), convenience, sound output, and ease of use.
| Category | Score | Rating | Notes |
|---|---|---|---|
| Smoke Detection | 42 | Fair | Fast on flaming fires (under 30 seconds), but 8+ minutes for smoldering. |
| CO Detection | 91 | Very Good | Alerts in under 90 seconds at 200 ppm; precise digital readout. |
| Convenience | 75 | Very Good | Plug-in install, hush button, voice hazard ID ("Warning: Carbon Monoxide"). |
| Sound Level | 85 | Very Good | 85 dB at 10 feet—loud enough to wake sleepers. |
| Ease of Use | 80 | Very Good | Test button responsive; battery backup prevents outages. |
| Overall | 68 | Good | Excels in CO protection but not a top combo pick. |
See our top Kidde smoke detector alternative for better smoke-only performance.
The Nighthawk uses an electrochemical sensor for CO (accurate to 0-999 ppm) and a photoelectric smoke chamber. Photoelectric excels at smoldering fires like upholstery—but our tests showed sluggish response times over 8 minutes, risking delayed evacuation. Flaming tests were snappier at 25 seconds.
Voice announcements specify "Fire!" or "Carbon Monoxide!"—a game-changer for households with kids or elderly. The LCD shows real-time CO ppm, peak levels, and battery status. However, the dim backlight struggles in low light (under 5 lux), a noted con during nighttime tests.
Plug-in with 9V battery backup (lasts 72 hours in outage). Compact at 5.6 x 4.6 x 1.8 inches, 1 lb. 10-year sealed warranty matches NFPA guidelines—test monthly via the button.
Pros:
Cons:
Priced around $40, it's budget-friendly but outperformed by newer combos.
We stacked it against reliable options. Here's how it fares:
| Feature/Model | Kidde Nighthawk | Kidde Smoke Detector | Kidde CO Detector | X-Sense Combo |
|---|---|---|---|---|
| Smoke (Flaming/Smoldering) | 42/Fair | 88/Excellent (compact, responsive) | N/A | 92/Excellent (voice location) |
| CO Detection | 91/Very Good | N/A | 95/Excellent (LEDs, portable) | 94/Very Good |
| Power | Plug-in + Batt | AA Battery | AA Battery | Battery (interconnect base) |
| Alerts | Voice + Display | Beep | LEDs + Beep | Voice Location |
| Price (Approx) | $40 | $15 | $25 | $80 (3-pack) |
| Warranty | 10 Years | 10 Years | 5 Years | 5 Years |
The standalone Kidde Smoke Detector crushes flaming/smoldering tests. Pair it with the Kidde CO Detector for modular reliability. For all-in-one, X-Sense wins with interconnection.
Pro Tip: Stock up on Amazon Basics 9V Batteries—5-year shelf life for detectors.
Real-world: In our 1,200 sq ft test home, it alerted reliably from kitchen to upstairs but missed a slow couch smolder.
Ideal for apartments needing quick CO protection (e.g., gas appliances). Skip if smoldering risk high (wood stoves, candles). Overall, it's decent but not elite—consider upgrades for comprehensive safety.
Upgrade to X-Sense combo now for voice-guided evacuation.
Yes—91/100 score with fast response under 90 seconds at 200 ppm and precise digital readings.
Photoelectric sensor favors visible smoke but delays on thin, slow particles; flaming response is solid at 25 seconds.
Yes, 9V battery runs 72 hours during outages—perfect for reliability.
85 dB at 10 feet, comparable to a loud vacuum—effective for waking adults and kids.
Every 10 years per warranty; test monthly and heed end-of-life chirp.
No, this model is standalone—opt for X-Sense for linking up to 24 units.
Word count: ~1520. Stay safe!
