First Alert SCO501CN Review

Est. $65
March 2015
by ConsumerSearch
First Alert SCO501CN Review

Best CO and Smoke Detector

  • Interconnects wirelessly
  • Easy to install
  • Very sensitive to smoldering fires
  • Voice warning
  • No digital display
  • Not sensitive to flaming fires
Where to Buy

Bottom line

If you are looking for protection against carbon monoxide and smoldering fires, the First Alert SCO501CN is a great choice. Testing reveals that it's a top performer against both types of threats. Installation is a breeze for homeowners as its wireless connectivity eliminates the need to snake wires through walls for a whole house system. It can also talk -- literally, in some cases, thanks to its voice-alert feature -- to other First Alert OneLink alarms, including CO-only models and smoke-only models, letting you tailor an ideal home protection system to guard every space, from the basement, to the kitchen, to the bedroom to the attic.

Breaking it down


CO and smoldering fire protection are top rated. If there's a shortfall, with the First Alert SCO501CN, it's that it has only a photoelectric smoke detector, not an ionization one. That's a good news/bad news story. The bad news is that lacking an ionization detector, the alarm is slow to respond to raging fires. The good news is that the photoelectric sensor the SCO501CN has is more effective against smoldering fires, experts say. It's also the type of smoke detector that's most likely to be missing in most homes. You can learn more about types of smoke detectors in our smoke detectors report. There are no reservations at all regarding CO detection -- it does well when faced with both high levels and low -- but still dangerous -- levels. The wireless OneLink technology the First Alert SCO501CN uses to communicate with other alarms has been around for a while, and is proven to be robust.

Ease of use

Simple interconnectivity. Experts say that whether you are installing CO detectors or smoke detectors -- or a combination model such as the First Alert SCO501CN -- having interconnected alarms provides the most complete protection for a typical home. Normally, that's a hassle, but the wireless OneLink system used by the SCO501CN makes things a lot easier by eliminating the need to run wires between detectors. OneLink works well, reviews say, and the mesh network it creates does a better job of getting into remote parts of the home than some other wireless systems. The only caveat is that you need to pick installation locations carefully so that one alarm is within range of another -- and that might require installing a couple of extra alarms to complete the network. Being completely battery operated makes that a little easier as you don't need to worry about things like outlet locations.

Otherwise, use is pretty straightforward. There's no digital readout, but feedback indicates that shortfall is made up for by the voice notification system. You can program each alarm to be at one of 11 locations, such as the basement, kitchen, master bedroom, etc. If that alarm is triggered, all other interconnected, voice-capable alarms will sound as well and announce which alarm has spotted the hazard -- minimizing confusion. The voice system also tells you which alarm has a low-battery condition or if another error is encountered.


More false alarms than CO-only alarms. We saw more complaints about false alarms with the First Alert SCO501CN than with most CO-only detectors, but that's not unexpected. In general, smoke alarms are more prone to false alarms than CO detectors, and we saw a similar pattern with other combination models. We saw a few reports of detectors that went through batteries at an excessive rate, but also reports of strong customer service from First Alert that replaced defective units hassle free. The First Alert SCO501CN was formerly covered by a five year warranty, but that's now been extended to seven years. Don't expect the alarm to last longer than that however, as an end-of-life alert (along with a voice announcement that will be heard on all connected voice capable alarms) will sound when that life expectancy is reached.

Where To Buy
Onelink Wireless Talking Battery Operated Smoke & Carbon Monoxide Alarm SCO501B2 - 2pk

 (220 reviews)
5 New from $94.99

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First Alert SCO501CN Reviews

1. editors rank the First Alert Onelink SCO501CN among six interconnected models and six stand-alone models. They conduct thorough testing for response time to high and low CO levels as well as features like voice alerts.

Review: First Alert OneLInk SCO501CN CO & smoke alarm, Editors of Consumer, Not Dated


We spotted more than 160 user reviews for the First Alert SCO501CN at, where it earns a rating of 4 stars. User complaints largely fall into two broad areas -- excessive false alarms and batteries that were expended too quickly. Most users are pleased, however, and we also saw reports of excellent customer service from First Alert, saying that the company honored the terms of its warranty with a minimum of hassle.

Review: First Alert SCO501CN-3ST Interconnected Battery Operated Combination Smoke and Carbon Monoxide Alarm with Voice Location, Contributors to, As of March 2015

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