Smoke alarms

We tested 20 models to see which respond fastest to smoke.

Smoke alarm on ceiling


Micro OM509-LS

worth considering


Avg price


Member Reviews

    Test results

    • 65
      Ease of use

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    How we test

    Overall score is based on smouldering and flaming fire sensitivity.

    Good” or “OK” meant the alarm sounded quickly enough to alert you to danger.
    Poor” meant the alarm took significantly longer to sound.
    Extreme” sensitivity meant the alarm sounded so quickly they are more likely to issue false alarms.

    Ease of use includes instructions and ease of installation.

    See "About our test" for more information.

    Noise is measured in a quiet room 3m from the alarm.

    Price is from a March 2018 price survey.

    More test results

    • Smouldering fire sensitivity


    • Flaming fire sensitivity



    • Avg price


    • Alarm type


    • Noise (dBA)


    • Battery type

      Sealed lithium

    • Size



    • Battery life (years)


    • Alarm life (years)


    • Warranty (yrs)


    • Hush period (min)


    • Carbon monoxide alarm

    • Alarms can be linked

    • Voice alerts

    More info

    • Notes


    • Availability

      Will be rebranded as the CodeRED CRM-100 from May.

    Member reviews

    1 Member review

    It sometimes is the after sales support that counts


    My OM509-LS developed a problem at about 30 months from manufacturing date.
    These come with a seven year warranty, and a query to the manufacturer resulted in the unit being replaced at no cost with the latest model within four days.
    I am very impressed by this level of customer support and these will now be my preferred smoke alarm.
    Only one false alarm over the time it was operational so no problems there.


    Hard to silence when you can't find the magnet to turn it off.
    The newer OM100H has a removeable battery so solves the problem.

    Recommend it?

    Yes, I recommend this product.


    Used 6 months or more