Heat alarm responds when temperature rises to about 58^oC and is suitable for kitchen, basement, warehouse, lofts and garages where false alarm may likely occur to smoke alarm due to steam or cooking flame or particles caused nuisance alarm. Tested and comply with BS5446: Part 1, Grade A1 prEN54; Pt5: Clause 5.4 (draft) F1 (21-07-97)E performance. The general ionization and optical smoke alarm will produce nuisance alarm if installed in a kitchen or garage. In some instance at very high temperature and humidity heat alarm is more effective and appropriate. All the Homewatch Heat Alarm are tested & complied with British standard.