An RTU, or rooftop unit, combines heating, cooling, ventilation, and air-distribution equipment in a packaged system installed on a commercial building’s roof. A useful RTU maintenance checklist helps property owners and facility managers document conditions, plan qualified service, and identify problems before they disrupt operations.

This checklist is designed for commercial properties in Brampton. It separates safe observations from electrical, gas, refrigerant, combustion, roof-access, and other technical work that should be completed by a qualified HVAC professional.

Before You Start: Set Safety and Service Boundaries

Gather the unit identifier, manufacturer and model information if available, maintenance history, filter details, previous repair notes, and occupant reports. Note when the concern began and whether it affects heating, cooling, ventilation, or all operating modes.

Operators may document visible damage, unusual sounds, water around accessible areas, blocked supply or return paths, thermostat complaints, and alarm messages from an authorized safe location. They should not remove protective covers, reach into moving equipment, open electrical panels, or attempt gas, combustion, refrigerant, or control-system repairs.

Health Canada guidance on ventilation maintenance recommends scheduled filter replacement and inspection by a qualified professional according to manufacturer recommendations. Federal workplace guidance also supports qualified maintenance planning and recordkeeping. Consider ongoing maintenance when reviewing the unit’s history or planning related heating work.

The Seven-Part RTU Maintenance Checklist

1. Safety, Access, and Unit Documentation

Record the property, unit identifier, manufacturer and model if available, date, operating mode, and person completing the observation. For properties with several rooftop systems, accurate identification prevents findings from being assigned to the wrong equipment.

From a safe viewpoint, note cabinet damage, missing panels, water entry, unusual odours, or unsafe access conditions. Record previous recommendations before anyone cleans, resets, adjusts, or replaces a component.

2. Filters, Airflow, and Occupant Comfort

Record the filter size and type if known, apparent condition, last change date, fit, unusual dust, weak airflow, blocked supply or return paths, and rooms that are consistently too warm or too cool.

There is no universal replacement interval for every RTU. Filter loading depends on equipment, building use, occupancy, outdoor conditions, and manufacturer guidance. If filters load unusually quickly or comfort problems continue, arrange qualified diagnosis rather than repeatedly changing filters without addressing the cause.

3. Coils, Drainage, and Moisture Problems

From an accessible location, record visible dirt, standing water, staining, wet insulation, damaged drain components, or water around the unit. Indoors, note ceiling stains, damp areas, or recurring condensation.

Coil cleaning, drain clearing, refrigerant work, and iced-coil diagnosis require appropriate training and equipment. Do not remove guards or panels to reach these components. Escalate persistent water, ice, or moisture promptly.

4. Fans, Belts, and Moving Components

Note changes in sound, vibration, airflow, or start-up behaviour. If a belt is visible without opening equipment or entering an unsafe area, record obvious cracking, fraying, looseness, or damage. Do not touch or adjust it.

Inspection inside guarded equipment, belt tensioning, lubrication, alignment, bearing assessment, and replacement are qualified-service tasks. Scraping, grinding, severe vibration, fan failure, or sudden airflow reduction should be treated as repair signals.

5. Electrical Components, Controls, and Safety Devices

Record thermostat behaviour, displayed fault codes, repeated alarms, unexpected shutdowns, and whether the unit responds to normal commands. Include the time and operating conditions when the fault occurs.

Do not open electrical panels, test energized components, reset repeatedly tripping equipment, handle exposed wiring, or bypass a safety device. Burning smells, sparks, buzzing, exposed conductors, or repeated electrical trips require qualified service.

6. Heating and Cooling Operation

Record whether heating and cooling start when requested, whether temperatures remain uneven, whether the unit cycles unusually often, and whether there is frost, water, an unusual smell, inadequate airflow, or a persistent alarm.

Gas, combustion, ignition, refrigerant, pressure, and performance testing must be handled by a qualified HVAC professional. Escalate gas or burning odours, loss of heating or cooling, repeated short cycling, visible frost, or returning alarms.

7. Seasonal Follow-Up and Preventive Service Planning

Before periods of heavier heating or cooling demand, review unresolved findings, filter requirements, occupancy needs, access arrangements, planned shutdowns, and manufacturer instructions. Set a review date and identify who is responsible for arranging service.

Maintenance should reflect the property. Offices, retail spaces, multi-tenant buildings, and industrial facilities may have different operating hours, ventilation needs, and access constraints.

For certain workplaces covered by Ontario Regulation 67/93, mechanical ventilation systems must be inspected by a qualified person at least every six months. This is not a blanket requirement for every commercial rooftop unit in Ontario. Confirm whether the regulation applies to the specific workplace and system.

When Routine Monitoring Should Become a Repair Call

• No heating, cooling, or required ventilation.
• Persistent alarms, repeated cycling, or shutdowns.
• Gas, burning, chemical, or unexplained electrical odours.
• Water entering the building, standing water, ice, or recurring moisture.
• Severe vibration, scraping, grinding, or fan failure.
• Exposed wiring, sparks, damaged panels, or repeated electrical trips.
• Problems requiring roof access, refrigerant handling, combustion testing, or guard removal.

Give the contractor the unit identifier, symptom, timing, operating mode, alarm information, safe photographs, and service history. Do not continue troubleshooting a hazardous fault just to complete the checklist.

A Simple RTU Maintenance Record Template

Keep one record for each unit. Include the property and unit identity, manufacturer and model if available, date, operating mode, filter condition and change date, visible findings, occupant complaints, alarms, work completed by qualified personnel, parts changed, unresolved concerns, recommendations, and next review date.

Consistent records support filter scheduling, help the next service provider understand what changed, and make recurring faults easier to identify. Federal guidance recommends keeping records of HVAC maintenance activities.

Questions to Ask Before Booking Commercial RTU Maintenance

• What will the visit include, and what will be documented?
• Will the work follow manufacturer recommendations and property conditions?
• Which tasks require roof access, shutdowns, or occupant coordination?
• How will urgent repairs and deferred work be reported?
• Will the record identify the unit, findings, parts, and follow-up recommendations?
• Which filter schedule suits this system and building use?
• Does a workplace-specific inspection requirement apply?
• What should the operator monitor between service visits?

FAQ

What does RTU stand for in HVAC maintenance?

RTU stands for rooftop unit. It is a packaged HVAC system installed on a roof that may provide heating, cooling, ventilation, and air distribution.

Can a building operator replace an RTU filter?

Some operators may replace an accessible filter when site procedures and equipment instructions allow it. They should not enter unsafe areas or work around moving, electrical, gas, combustion, or refrigerant components.

How often should a rooftop unit be inspected?

Frequency depends on manufacturer recommendations, system condition, building use, occupancy, filter loading, and applicable requirements. A qualified person can help establish a property-specific plan.

What RTU problems require immediate professional service?

Gas or burning odours, electrical hazards, water intrusion, severe vibration, exposed wiring, loss of heating or cooling, persistent alarms, and repeated shutdowns require professional attention.

Does Ontario require every commercial RTU to be inspected every six months?

No. The six-month requirement applies to certain mechanical ventilation systems in workplaces covered by Ontario Regulation 67/93. It is not a blanket rule for every commercial building or RTU.

What belongs in an RTU maintenance log?

Include the unit identity, date, operating mode, filter information, findings, alarms, qualified work, parts changed, unresolved concerns, recommendations, and next review date.

Use the Checklist to Plan the Next RTU Service Visit

A good checklist supports safe observation, useful records, seasonal planning, and timely escalation. It does not replace qualified inspection or technical work involving electrical, gas, combustion, refrigerant, moving equipment, or roof-access hazards.

For commercial property owners and managers in Brampton, RealAir Solutions Inc. provides commercial HVAC installation, maintenance, repair, and emergency services. The company reports more than 25 years of HVAC experience and certified technicians serving residential and commercial customers.