A basic visual check may identify obvious damage or a panel fault. However, a professional AOV inspection goes further by examining the installed equipment, testing system operation and reviewing available maintenance records.

At

AK Fire Safety
,
we provide professional

AOV inspections, servicing, repairs and maintenance

throughout the United Kingdom.

What Is the Purpose of an AOV Inspection?

The main purpose of an AOV inspection is to establish whether the smoke-control system appears suitable, remains in serviceable condition and operates as intended.

An inspection can help:

• Identify electrical and mechanical faults
• Confirm that vents and dampers operate
• Check whether the correct equipment activates
• Identify failed or ageing standby batteries
• Find damaged actuators and obstructions
• Check fire-alarm interfaces
• Review control-panel faults and indications
• Confirm that testing and maintenance records are available
• Highlight missing labels or documentation
• Provide recommendations for servicing, repairs or upgrades

The Main Stages of an AOV Inspection

1. Reviewing the Fire Strategy and System Information

Before operating the system, the engineer should try to understand what it is intended to do.

Useful documents may include:

• The building fire strategy
• Smoke-control cause-and-effect information
• System drawings and zone plans
• Commissioning certificates
• Previous service reports
• Previous inspection reports
• Manufacturer manuals
• Battery replacement records
• Fault and repair history
• Building fire-risk assessment

Where documents are missing, the engineer may still inspect and test accessible equipment. However, the absence of design information may limit what can be confirmed.

2. Identifying the Type of Smoke-Control System

AOV systems vary significantly. Therefore, the engineer first needs to identify the type of system installed.

3. Inspecting the AOV Control Panel

The control panel coordinates the operation of the smoke-control system. Therefore, its condition and indications form an important part of the inspection.

The engineer may check:

• Normal, fire and fault indications
• Power-supply status
• Battery or charger warnings
• Disabled or isolated circuits
• Panel labels and zone descriptions
• Physical damage or corrosion
• Signs of overheating
• Loose covers or exposed openings
• Available event or fault history
• Operating and reset controls

A panel fault should not simply be reset without investigation. Instead, the cause should be identified and recorded.

4. Inspecting Mains and Standby Power

Smoke-control systems require dependable electrical power. In addition, many systems include standby batteries or another secondary supply.

The inspection may include:

• Checking that the normal supply is present
• Checking supply labels and isolation arrangements
• Inspecting visible cables and connections
• Checking the panel response to a supply fault
• Inspecting battery age and condition
• Checking for swelling, leakage or corrosion
• Measuring charging and battery voltage
• Assessing battery performance where appropriate

5. Inspecting Smoke Detectors

Smoke detectors normally provide the automatic signal that starts the AOV sequence.

The engineer may inspect:

• Detector position and identification
• Visible contamination or damage
• Obstructions around the detector
• Detector bases and connections
• Interface arrangements with the fire alarm
• The detector response to suitable test equipment
• The resulting AOV system operation

The test should prove more than the detector entering alarm. It should also confirm that the correct smoke-control equipment operates.

Learn more about our

fire-alarm installation and maintenance services
.

6. Inspecting AOV Actuators

Actuators physically move windows, rooflights, louvres and dampers. They can use chain, spindle, linear or rack mechanisms.

During inspection, the engineer may check:

• Actuator body and mechanism
• Mounting brackets and fixings
• Electrical cable condition
• Signs of water ingress or corrosion
• Unusual noise or vibration
• Opening and closing speed
• Full travel and final position
• Correct attachment to the vent
• Damage caused by forcing or obstruction

An actuator that makes a noise but does not fully open the vent should be recorded as a defect.

7. Inspecting Windows, Rooflights and Smoke Vents

The engineer should inspect the complete ventilation opening rather than the actuator alone.

Checks may include:

• Full opening movement
• Frame and hinge condition
• Damaged or distorted components
• Unauthorised locks, screws or restraints
• Stored items obstructing movement
• Weather damage and water ingress
• Stability in the open position
• Correct closing and reset
• Visible seals and drainage arrangements

Vents positioned on roofs or at high level may require safe access arrangements. Consequently, access restrictions should be identified before the inspection.

8. Inspecting Smoke-Shaft Dampers

Smoke-shaft dampers connect a corridor or lobby to a vertical smoke shaft. Their correct operation is essential to the system’s cause-and-effect sequence.

The inspection should establish whether:

• The correct floor damper opens.
• Dampers on unaffected floors remain in their required positions.
• The damper reaches its full opening position.
• The actuator and linkage operate smoothly.
• The damper is clear of obstructions.
• The panel receives the correct status signal.
• The damper resets after testing.

Opening the wrong floor damper can affect the performance of the smoke shaft. Therefore, floor-by-floor operation should be carefully recorded.

9. Inspecting the Head-of-Shaft Vent

Natural smoke shafts usually include an automatic vent at the top of the shaft. This may be a rooflight, louvre or dedicated smoke ventilator.

The engineer should confirm that the vent:

• Opens automatically when required
• Reaches its intended position
• Works with the correct floor damper
• Remains unobstructed
• Shows no obvious physical damage
• Closes and resets correctly

Testing a floor damper without testing the head-of-shaft vent could leave a significant fault undetected.

10. Inspecting Mechanical Extract Fans

Mechanical smoke-control systems use powered fans to extract smoke through shafts or ductwork.

Where accessible and applicable, the engineer may check:

• Automatic fan starting
• Control-panel and local indications
• Visible fan and motor condition
• Unusual noise or vibration
• Associated damper operation
• Normal and secondary power supplies
• Manual override controls
• Correct shutdown and reset

Detailed airflow or performance testing may require additional specialist equipment and a separate scope of work.

11. Inspecting Replacement-Air Arrangements

Smoke leaving a building normally needs to be replaced by incoming air. This is known as replacement air or make-up air.

The inspection may include:

• Automatically opening entrance doors
• Low-level windows
• External louvres
• Dedicated air inlets
• Mechanical supply fans
• Controls linking the inlet to the smoke-extract system

The engineer should confirm that the replacement-air arrangement operates at the correct time and remains unobstructed.

12. Testing Manual and Firefighter Controls

Manual controls may allow authorised users or firefighters to operate parts of the smoke-control system.

During inspection, the engineer may check:

• Accessibility and location
• Clear labelling
• Physical condition
• Open, close and automatic functions
• Firefighter override operation
• Correct panel indications
• Reset procedures

Controls should operate according to the approved cause-and-effect strategy. Therefore, unauthorised programming changes should be investigated.

13. Completing Cause-and-Effect Testing

Cause and effect describes how the system should respond after an input activates.

For example, smoke detection on one residential floor may need to:

1. Open the smoke-shaft damper on the affected floor.
2. Keep dampers on other floors closed.
3. Open the vent at the head of the shaft.
4. Open the designated replacement-air inlet.
5. Start an extract fan where installed.
6. Display the correct status at the control panel.

Testing components individually may not identify incorrect system programming. Therefore, end-to-end cause-and-effect testing is an important part of a thorough inspection.

Common Faults Found During an AOV Inspection

What Happens After the Inspection?

After completing the inspection, the engineer should reset the system and confirm that it has returned to its normal condition.

The client should receive a report that may include:

Where faults are found, repairs should be arranged promptly. The affected equipment should then be retested to confirm that the repair has restored correct operation.

How Long Does an AOV Inspection Take?

The time required depends on the size and complexity of the system.

Factors include:

• The number of floors
• The number of vents and actuators
• The number of smoke-shaft dampers
• Whether mechanical fans are installed
• Access to roof and high-level equipment
• The availability of documentation
• The number of faults found
• Whether fire-alarm interface testing is included
• Whether all equipment is tested in one visit

A single stairwell vent may take considerably less time than a multi-storey mechanical smoke-control system.

How Often Should AOV Inspections Be Completed?

The correct inspection and servicing frequency should follow the building fire strategy, risk assessment, manufacturer instructions and applicable standards.

Many smoke-control systems receive professional maintenance at least every six months. In addition, routine checks may be completed more frequently.

Applicable high-rise residential buildings in England are also subject to monthly routine checks of key firefighting equipment, including smoke-control systems.

View the official

GOV.UK Fire Safety (England) Regulations guidance
.

What Legal and Technical Guidance Applies?

Relevant documents may include:

• Regulatory Reform (Fire Safety) Order 2005 – requires relevant fire-safety measures and equipment to be subject to suitable maintenance.
• Fire Safety (England) Regulations 2022 – introduces additional checks for applicable high-rise residential buildings.
• BS 7346-8 – recommendations for planning, design, installation, commissioning and maintenance of smoke-control systems.
• BS EN 12101 series – standards covering smoke and heat control equipment.
• The building fire strategy, manufacturer instructions and fire-risk assessment.

Read

Article 17 of the Regulatory Reform (Fire Safety) Order 2005

on the official legislation website.

Information about

BS 7346-8

is available from BSI.

Frequently Asked Questions

Professional AOV Inspections from AK Fire Safety

AK Fire Safety provides professional AOV inspections for apartment blocks, managing agents, housing providers, landlords, commercial premises and public-sector organisations.

Our services include:

• AOV condition inspections
• Smoke-control system surveys
• Control-panel testing
• Battery inspection and replacement
• Detector testing
• Actuator and vent testing
• Smoke-shaft damper testing
• Mechanical extract-fan testing
• Replacement-air testing
• Fire-alarm interface testing
• Cause-and-effect testing
• Fault diagnosis and repairs
• System commissioning and upgrades
• Nationwide planned maintenance

Conclusion

During an AOV inspection, the engineer examines the installed smoke-control equipment, checks its physical condition and tests how the system responds to automatic and manual activation.

A complete inspection may cover the control panel, power supplies, batteries, detectors, actuators, windows, roof vents, smoke-shaft dampers, extract fans and replacement-air openings.

Most importantly, the inspection should confirm that the complete cause-and-effect sequence works rather than testing individual parts without checking the final response.

Any defects should be recorded, repaired and successfully retested so the system remains ready for emergency operation.