Updated November 2026
Data from the official Heiman site.
2026 verdict
In this 2026 Heiman Smoke Alarm HM-636PHS vs Heiman Carbon Monoxide Detector C1-S comparison, Heiman Smoke Alarm HM-636PHS comes out ahead thanks to price, tests itself, and steam check.
The main reason it wins is price, tests itself, and steam check, and its broader overall balance strengthens that case. Heiman Carbon Monoxide Detector C1-S can still be the right pick, but only if rating outweighs the wider strengths of Heiman Smoke Alarm HM-636PHS. As a general recommendation, Heiman Smoke Alarm HM-636PHS comes out on top.
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| Feature | Heiman Carbon Monoxide Detector C1-S | Heiman Smoke Alarm HM-636PHS | Winner |
|---|---|---|---|
| Price | $29.99 | $24.99 | Heiman Smoke Alarm HM-636PHS |
| Rating | 4.4 | 4.2 | Heiman Carbon Monoxide Detector C1-S |
| Tests Itself | NO | YES | Heiman Smoke Alarm HM-636PHS |
| Steam Check | NO | YES | Heiman Smoke Alarm HM-636PHS |
| Warranty | 10 years | 10 years | Tie |
| Battery Life | 10 years | 10 years | Tie |
| Screen | NO | NO | Tie |
| Sensors | CO | Smoke | Tie |
| Alerts | CO Alerts, Low Battery Alerts | Fire Alerts, Low Battery Alerts | Tie |
| Built-in Siren | YES | YES | Tie |
| Built-in Light | NO | NO | Tie |
| Pathlight | NO | NO | Tie |
$29.99
- + Rating: 4.4
- - Price: $29.99 vs $24.99
- - Tests Itself: NO vs YES
Winner
17% OFF
Prime exclusive deal$24.99
$29.99
- + Price: $24.99
- + Tests Itself: YES
- + Steam Check: YES
- - Rating: 4.2 vs 4.4
Frequently Asked Questions
Which is better overall: Heiman Carbon Monoxide Detector C1-S or Heiman Smoke Alarm HM-636PHS?
Heiman Smoke Alarm HM-636PHS has the stronger overall profile in this comparison, especially for price, tests itself, and steam check.
What is the biggest difference between Heiman Carbon Monoxide Detector C1-S and Heiman Smoke Alarm HM-636PHS?
Price is one of the clearest differences: Heiman Carbon Monoxide Detector C1-S lists $29.99, while Heiman Smoke Alarm HM-636PHS lists $24.99.
Which one looks better on price?
Heiman Carbon Monoxide Detector C1-S is listed at $29.99, while Heiman Smoke Alarm HM-636PHS is listed at $24.99. Heiman Smoke Alarm HM-636PHS (better spec).
Who should buy Heiman Carbon Monoxide Detector C1-S?
Choose Heiman Carbon Monoxide Detector C1-S if your priority is rating and that matters more than price.
Who should buy Heiman Smoke Alarm HM-636PHS?
Choose Heiman Smoke Alarm HM-636PHS if your priority is price and tests itself and that matters more than rating.
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Compare all 28 Smoke & CO Detectors side by side
You are looking at two of them. The full table lines up all Smoke & CO Detectors in the catalog with the same specs, so you can filter by what you need and sort by price or rating.
- 28 Smoke & CO Detectors
- 45 specs compared
- 42 filters
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Smart Smoke Detector
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XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts
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Smoke and CO Alarm HM-636THS
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Matter Smoke Detector S1-TM
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SD19-MN Interconnected Smart Smoke Alarm
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Wi-Fi Smoke Alarm
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Smart Smoke & CO Detector with Ring
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Smoke Alarm E10
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Interconnected Smoke Alarm S1-R
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Interconnected CO Alarm C1-R
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SC5 Battery Smart Smoke & CO Alarm
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SMCO410 Smoke Detector & CO Alarm
- Door & Window Sensors
Window Door Alarm
- Gas Detectors
HS1CG Series Combustible Gas Sensor
- Gas Detectors
WS2CG Series Combustible Gas Detector
- Motion Sensors
Smart Motion Sensor
- Motion Sensors
WiFi Smart Motion Sensor
- Sirens
Smart Siren HS2WD series
- Smoke & CO Detectors
HS1SA-E Zigbee Smoke Alarm
- Smoke & CO Detectors
Interconnected CO Alarm C1-R
- Smoke & CO Detectors
Interconnected Smoke Alarm S1-R
- Smoke & CO Detectors
Matter Smoke Detector S1-M
- Smoke & CO Detectors
Matter Smoke Detector S1-TM
- Smoke & CO Detectors
Smart CO Alarm
- Smoke & CO Detectors
Smoke and CO Alarm HM-636THS
- Vibration Sensors
Smart Vibration Sensor HS1VS series
- Water Leak Sensors
Smart Water Leakage Sensor