A rooftop unit can keep running while problems quietly build. A worn belt, a weak capacitor, a dirty coil, or a clogged drain may not cause trouble today, but each one puts extra strain on the system. Regular maintenance helps:

• Catch problems early. Small issues are usually faster and less expensive to fix before they lead to a breakdown.
• Keep your space comfortable. Clean coils, good airflow, and properly working controls help the unit heat and cool the way it should.
• Control energy costs. Dirty coils, loaded filters, and faulty economizers make the unit work harder than it needs to.
• Protect your building. A blocked condensate drain can overflow into the cabinet or the ceiling below.
• Keep it safe. Gas heating sections need regular checks of the burners, heat exchanger, venting, and safety controls.
• Plan repairs on your schedule. Finding a worn part during a planned visit is much easier on your business than an emergency call during peak season.
• Build a service history. Records of each visit help track the unit’s condition and plan for future replacement.

Maintenance can’t prevent every failure or guarantee how long a unit will last. But it gives you a clear picture of your equipment’s condition so there are fewer surprises.

Most rooftop units should be serviced twice a year:

• Spring: Before cooling season. We focus on the cooling side, including coils, refrigerant system, condensate drain, and economizer.
• Fall: Before heating season. We focus on the heating side, including burners, heat exchanger, gas pressure, venting, and safety controls.

Filters may need changing more often, depending on how dusty your space is and the type of filter. Restaurants, warehouses, and buildings near construction may need more frequent visits. Your unit’s manufacturer instructions should also be followed.

Every visit follows a documented checklist, so nothing gets missed and you have a record of what was found.

Prep and safety

• Review service history. Check previous maintenance records and notes for the unit.
• Record unit details. Make, model, serial number, refrigerant type, and age.
• Power off and lock out. Confirm the unit is safely isolated before inspection.
• Inspect the disconnect. Check the disconnect or fused disconnect for condition and proper operation.
• Inspect main wiring and connections. Look for loose connections, damage, or signs of overheating.

Maintenance checks

• Check thermostat and controls. Confirm the thermostat settings and that the unit responds properly in both heating and cooling.
• Inspect and replace filters. Replace or clean filters as needed and confirm they fit and seal properly in the rack.
• Inspect belts. Check for cracking, glazing, and wear, and adjust tension where equipped.
• Inspect the blower wheel and motor. Clean the blower wheel if dirty and check the motor and bearings.
• Inspect the outdoor fan. Check the fan blade, motor, and mounting.
• Inspect and clean the condenser coil. Remove dirt, debris, and buildup that restrict airflow.
• Inspect the evaporator coil. Check for dirt, damage, or buildup.
• Check the economizer. Confirm the dampers, actuator, and sensors work properly where equipped.
• Inspect the drain pan and condensate line. Make sure water drains freely and the pan is free of corrosion or buildup.
• Inspect contactors and capacitors. Look for pitting, swelling, or wear.
• Check for refrigerant leak signs. Look for oil staining or damage on refrigerant lines and components.
• Inspect the heat exchanger. Look for cracks, corrosion, or other damage. A cracked heat exchanger is a safety hazard, and the unit cannot be operated until it’s corrected.
• Inspect the burners. Check for proper flame, rust, and debris.
• Test the ignition system and flame sensor. Confirm the unit lights reliably and proves flame.
• Inspect the flue and vent. Check for blockage, corrosion, or deterioration.
• Test safety controls. Confirm high limits, rollout switches, and pressure switches work as intended.
• Inspect the cabinet, panels, and seals. Check for missing screws, damaged panels, and worn door gaskets.
• Inspect the roof curb. Look for gaps, damaged sealant, or signs of water getting into the building.

Final checks

• Run a full operating test. Cycle the unit through heating and cooling and confirm everything works properly.
• Document and report. Record readings, take photos, and note any recommended repairs. Any repairs are quoted separately for your approval.

These readings are recorded each visit, so we can compare them over time and spot a trend before it turns into a problem.

These are some of the issues we find most often:

• Restricted airflow from loaded filters, dirty coils, or worn belts
• Dirty condenser coils that make the unit work harder in summer
• Weak capacitors and worn contactors, two of the most common causes of no-cooling calls
• Clogged condensate drains that lead to water leaks into the cabinet or building
• Ignition and flame sensor problems that stop the unit from heating
• Economizer faults that waste energy or let in too much outdoor air
• Refrigerant leaks that reduce cooling capacity
• Worn curb seals that let water into the building
• Cracked heat exchangers that create a safety hazard

Rooftop units are a significant investment, and replacing one rarely happens at a convenient time. A little planning can make a big difference.

Use maintenance to plan, not just repair. Every maintenance visit tells us something about your unit’s condition. Over time, those records show whether the unit is holding steady or starting to need more frequent repairs. That makes it easier to budget for replacement a year or two ahead, instead of being caught off guard.

Signs it may be time to plan for replacement

• The unit is approaching the end of its expected service life
• Repairs are becoming more frequent or more expensive
• A major component, like a compressor or heat exchanger, has failed
• The unit uses an older refrigerant that’s being phased out, and has a leak
• Replacement parts are becoming harder to find
• Energy costs are climbing or the unit struggles to keep up

As a rough guide, many owners start planning replacement when the cost of repairs over the past few years adds up to a large share of what a new unit would cost. We’ll give you an honest assessment so you can make the call that’s right for your building and budget.

Planned replacement vs emergency replacement A planned replacement lets you compare options, schedule the work during a quieter season, and avoid after-hours rates and downtime. An emergency replacement during a heat wave or cold snap limits your choices and can disrupt your business.

What goes into a replacement cost The price of the unit itself is only part of the project. A full quote can also include:

• Crane or lift to set the new unit on the roof
• Curb adapter if the new unit doesn’t match the existing curb
• Gas, electrical, and condensate connections
• Control and thermostat updates
• Permits and inspections
• Removal and disposal of the old unit
• Startup and commissioning

We list these items in our quote, so you can see the full scope before any work begins.

When it’s time to replace a rooftop unit, we install equipment from Rheem, SureComfort, and Daikin. Every installation starts with a look at your building’s heating and cooling needs, existing curb and ductwork, gas and electrical supply, and roof access.

From there, we handle the crane lift, connections, startup, and testing, and make sure the new unit is set up and running properly before we leave.

Whether you have one rooftop unit or several, our technicians can help keep your equipment running reliably and your budget predictable. We serve commercial properties across Markham, Richmond Hill, Stouffville, Unionville, Thornhill, and surrounding communities.

Learn more about our commercial maintenance plans