The Ontario Building Code | Silencing of Alarm Signals
220.127.116.11. Silencing of Alarm Signals
(1) Except as permitted by Sentence (3), a fire alarm system shall be designed so that when an alarm signal is actuated it cannot be silenced automatically before a period of time has elapsed that is not less than,
(a) 5 min for a buildingnot required to be equipped with an annunciator, and
(b) 20 min for any other building.
(2) Except as permitted by Sentences 18.104.22.168.(9) and 22.214.171.124.(3) and (4), a fire alarm system shall not incorporate manual silencing switches other than those installed inside the fire alarm control unit.
(3) Except as provided by Clause 126.96.36.199.(4)(a), in a care and treatment occupancy an alert signal is permitted to be silenced automatically after 1 min.