What a silent alarm does and does not prove · review
A display alarm with a 7-year life and 3-year warranty, from a less known brand, with 212 ratings at 4.6 out of 5.
SITERWELL gives an electrochemical sensor, an LCD, a 3-color LED, a 7-year life and a 3-year warranty, and says it conforms to ETL standards.
A home CO alarm is built to hold off at low levels: see our UL 2034 page for the alarm windows. A silent alarm does not prove the air is free of CO.
If the alarm sounds, get everyone outside to fresh air and call 911 or the fire department from there. Check the replace-by date, and follow the manual and your local code on where to mount it.
Prices quoted in this text are dated readings and can differ from the live price at the top of the page.
| Power | 2 AA batteries, built in |
|---|---|
| Display | LCD, real-time CO |
| Sensor | Electrochemical |
| Life | 7 years |
| Standard | ETL listed, stated |
| Warranty | 3 years |
| Amazon reference | B0BFQJRQZW |
Seven years, according to the listing.
Yes, on an LCD.
8.3/ 10
First Alert’s CO710 has a longer stated life.
This model is listed on Amazon.com, at ≈ $50 at the last reading. Listed is not the same as in stock: availability changes daily, and the buy box shows the live price.
Details checked on November 14, 2026.
A buyer who finds it on sale.
Specifications: the manufacturer sheet for wood heating equipment and the matching Amazon product page. Prices, ratings and availability: read on Amazon.com from a New York address. Every figure on this page names its source.
Same shelf, closest price — what the same spend else heats.
2 AA batteries · electrochemical · 85 dB · LEDs · Event Memory · portable
A small AA alarm with Event Memory, which records the last time it detected CO, with 2,356 ratings at 4.7 out of 5.
Best for: A cabin or travel alarm, or a second alarm at home.
≈ $25
plug-in · 9V backup · digital display · 85 dB · 3rd edition
The older Kidde plug-in with a digital display, a 9V backup and 28,356 ratings at 4.7 out of 5.
Best for: A buyer who trusts a long record over a newer model.
≈ $70
10-year sealed battery · photoelectric smoke · electrochemical CO · LCD · UL 217 and UL 2034 stated
A 10-year combination alarm with an LCD, naming both UL 217 and UL 2034, the same price as First Alert’s battery combo.
Best for: A single unit for a hallway outside the bedrooms.
≈ $37
