FA6720-R Kitchen Heat Alarm with Sealed 10-Year Battery

A heat alarm detects rapid rises in temperature rather than smoke particles. The FA6720-R uses a thermistor sensor that triggers when ambient temperature reaches between 54 and 65 degrees Celsius. This makes heat alarms ideal for kitchens, garages and utility rooms where cooking fumes, steam or dust would cause a smoke alarm to false alarm.

A smoke alarm detects smoke particles using an optical or ionisation sensor, while a heat alarm detects temperature changes using a thermistor. Smoke alarms are designed for bedrooms, hallways and living rooms. Heat alarms are designed for kitchens, garages and utility rooms where smoke alarms would trigger false alarms from cooking or fumes. Most homes need both types for full coverage. See our guide on what fire alarms to install and where.

A single chirp from the FA6720-R typically means the sealed battery is reaching end of life. Because the battery is sealed and tamperproof, it cannot be replaced. Use the Sleep Easy function to silence low-battery chirps for 8 hours overnight. When the alarm reaches end of life after 10 years, replace the entire unit. See our guide to maintaining and testing your heat alarm for more detail.

Heat alarms trigger at temperatures between 54 and 65 degrees Celsius. If your heat alarm triggers frequently, check that it is not positioned directly above a hob, oven or toaster where concentrated heat rises. Reposition the alarm further from the heat source while keeping it on the ceiling. If the alarm continues to trigger without an obvious heat source, it may be faulty and should be replaced.

Unlike smoke alarms, heat alarms have been specifically designed for areas with fumes and high humidity e.g. kitchens where cooking fumes are present and attics or garages where there is lots of dust and usually high humidity. Nearly 50% of fires start in kitchens in domestic properties – installing a heat alarm in this room will mean you’re rapidly alerted to danger and reduce the number of nuisance alarms.

Find out the difference between smoke alarms and heat alarms.

Yes. The FA6720-R is designed for any room where smoke alarms are unsuitable. This includes garages, unconverted loft spaces, utility rooms and boiler rooms where dust, fumes or humidity would trigger false alarms from a smoke detector. The alarm operates in temperatures from 4 to 38 degrees Celsius, so it is suitable for unheated spaces that do not freeze.

Press the test/hush button once for a quiet self-test at reduced volume, at least 10dB below the full alarm. Double-press for a full-volume 85dB test. Test at least once a month. See our full guide to maintaining and testing your heat alarm for more detail.

Yes. The FA6720-R is the direct replacement for the discontinued HT-630 heat alarm. It uses the same baseplate, so you can swap units without drilling new holes. The FA6720-R offers upgrades including a 10-year sealed lithium battery, thermistor sensor technology, quiet self-test and Sleep Easy mode. If your HT-630 is chirping continuously, it has reached end of life and should be replaced with the FA6720-R.