Automatic opening vents (AOVs) and smoke ventilation systems need routine in-house checks plus periodic servicing by a competent specialist. They are life safety systems, and the legal duty to keep them working sits with the building’s Responsible Person. This guide covers what the law requires, typical testing frequencies and the records you should hold.<\/p>\n
An AOV is a vent \u2013 usually at the head of a stairwell or in a common corridor \u2013 that opens automatically when the fire alarm or a smoke detector activates. It clears smoke and heat from escape routes so occupants can get out and firefighters can get in. You may also see these systems described as natural smoke and heat exhaust ventilators (NSHEVs), smoke vents or smoke control systems. Larger buildings may have mechanical smoke extract systems with fans and dampers.<\/p>\n
Because they sit idle for most of their life, AOVs are prone to hidden faults: seized actuators, flat batteries, blocked openings and control panels left in fault. A vent that does not open during a fire can allow escape routes to fill with smoke.<\/p>\n
The Responsible Person under the Regulatory Reform (Fire Safety) Order 2005<\/a>. Article 17 requires facilities and equipment provided for fire safety to be maintained in an efficient state, in efficient working order and in good repair. That applies to AOVs and other smoke control equipment in common parts and non-domestic premises.<\/p>\n The Fire Safety (England) Regulations 2022<\/a>, in force since 23 January 2023, added duties for multi-occupied residential buildings. In high-rise residential buildings (18 metres or more), they include monthly checks of lifts for firefighters and essential fire-fighting equipment, with faults reported to the fire and rescue service if they cannot be fixed within 24 hours.<\/p>\n For higher-risk buildings \u2013 at least 18 metres or seven storeys tall with at least two residential units \u2013 the Building Safety Act 2022 also introduces Accountable Person and Principal Accountable Person roles. Maintenance tasks can be delegated to a contractor, but the legal responsibility stays with the duty holder.<\/p>\n The exact regime should follow the system manufacturer’s instructions, the building’s fire strategy and the relevant British Standards (BS 9999 and BS 9991 include testing and maintenance recommendations for smoke control, and BS 7346-8 covers smoke control systems from design through to maintenance). A typical schedule looks like this:<\/p>\n Specialist servicing should be carried out by an organisation with demonstrable competence in smoke control. Third-party certification schemes for smoke control servicing exist and are a useful way to check a provider’s competence.<\/p>\n Keep a logbook showing test dates, which zones or vents were operated, faults found, remedial action taken and service certificates. Records are the only way to demonstrate that the system has been kept in efficient working order if the fire and rescue service, an insurer or a regulator asks. Where a new contractor takes over an existing system, it is good practice to carry out a full inspection first, so that existing defects are identified and recorded.<\/p>\n The Responsible Person can face enforcement action under the Fire Safety Order, and a fire and rescue service inspection that finds no maintenance records will usually treat that as a failure in itself. The practical risks are just as serious: vents that will not open, failed standby batteries and control panels that have been left in fault for months. Problems found during routine testing are almost always cheaper and quicker to fix than a failure discovered during an emergency.<\/p>\n Yes, and it should. Fragmented records are where many buildings fall down, because no one can see the full picture when different contractors hold different logs. Delta First’s full compliance management service<\/a> brings statutory compliance planning and record-keeping into one calendar with one accountable contractor. Delta First can arrange AOV and smoke ventilation servicing through vetted specialist subcontractors, while our directly employed electrical team handles planned electrical maintenance<\/a> and commercial EICR testing<\/a> for the same building.<\/p>\n Routine operational checks by a nominated person (typically weekly or monthly) plus specialist servicing, typically every six months and at least annually, in line with the manufacturer’s instructions and the fire strategy.<\/p>\n A trained nominated person can carry out routine checks. Servicing and functional testing should be done by a competent smoke control specialist.<\/p>\n Yes. The Fire Safety Order duty to maintain fire safety equipment applies whatever the building’s height. The additional Building Safety Act duties apply to higher-risk buildings.<\/p>\n Test dates, zones operated, faults found, remedial action taken and service certificates.<\/p>\nHow often should AOV systems be tested and serviced?<\/h2>\n
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What records should building owners keep?<\/h2>\n
What happens if AOV maintenance is missed?<\/h2>\n
Can AOV testing sit alongside the rest of our compliance?<\/h2>\n
Frequently asked questions<\/h2>\n
How often should AOVs be tested?<\/h3>\n
Who can carry out AOV maintenance?<\/h3>\n
Does AOV maintenance apply to buildings under 18 metres?<\/h3>\n
What records should be kept?<\/h3>\n
Key takeaways<\/h2>\n
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Talk to Delta First<\/h2>\n