Free checklist
Air handling unit quarterly maintenance checklist
A quarterly air handling unit round is short on purpose: it catches the wear items that fail between annual services. This checklist is sized for a tech with a phone. Every item says what to look at and the photo that proves the round happened. Work is commonly verified against ASHRAE guidance, SMACNA duct construction. Confirm the edition your authority having jurisdiction has adopted.
The checklist
Every item, and the photo evidence it needs
The photo count on each row is what RTI would require before the item can be submitted. Work the list here and watch the gate hold, or load it into RTI and let it enforce the real thing.
Running walk-down
Controller readings and alarms noted before shutdown
Discharge air temperature, fan status and any active alarm read at the unit controller or BAS screen while the unit runs.
Every energy source feeding the unit locked and tagged
Each fan, heater, drive and control circuit locked, tagged and proven dead; damper and drain-safety checks run under the procedure's temporary release, people clear, then re-locked.
Air path
Filters pulled and inspected, not peeked at
One filter removed per bank, loading and bypass gaps checked, replacement date or pressure drop recorded.
Coils clean and fins undamaged
Face of the coil inspected for matting and biological growth, fins not flattened across the air path.
Dampers cycle and seal
Outside, return and mixing dampers driven full stroke, blades closing tight, linkage pinned.
Intake and mixing section checked for debris and water entry
Intake screen or return plenum free of debris and leaves, no rain or snow staining on the mixing section floor.
Drive and fan
Belt tension and condition verified
Deflection measured against the drive spec, no glazing, cracking or misalignment dust.
No photoFan and motor bearings checked
No play, noise or heat at the bearings, grease lines intact where fitted.
Fan wheel turns free and sits secure on the shaft
Wheel turned by hand with the unit re-locked, no rub at the inlet cone, hub and set screws tight on the shaft.
Drainage
Condensate pan clean and draining
Pan free of slime and standing water, trap primed, drain line flowing.
Drain safety devices tested where fitted
Float switch or pan sensor actually trips the unit or alarms, not just present.
No photoSection downstream of the coils checked for water carryover
Floor and liner downstream of the coils and pan dry, no wet insulation or rust streaks from moisture blown off a coil.
Return to service
Guards refitted and every access door latched
Belt and fan guards back on, doors closed and latched, no tools or filter packaging left inside the sections.
Lock removed by its owner and the unit restarted and run
Lock and tag removed by the person who hung them, fan restarted and run to steady airflow with no new controller alarm.
No photoQuarterly readings and deficiencies logged to the unit history
Filter, belt, bearing and drain findings entered against the unit tag, open deficiencies reported to the owner.
No photo
What usually sends this back
The failures are almost always the evidence, not the work
- Filter condition judged through the rack gap instead of pulling one and looking at it.
- Condensate pan checked in cooling season only, then the heating-season leak finds the ceiling below.
- Belt tension logged as 'ok' with no deflection check, and the belt fails under the first real load.
Verified against
Common questions
6 answers
- What does this air handling unit quarterly checklist cover?
- 15 items across 5 sections, covering running walk-down, air path, drive and fan, drainage, and more. Each item spells out what the person walking the job is actually looking for, not just a box to tick.
- Who should run this inspection?
- The HVAC service tech on the contracted quarterly visit.
- When in the schedule should this walk happen?
- Every quarter, timed ahead of the season change so a failing component is found before the unit is needed hardest.
- Why do these items ask for a photo?
- 11 of the 15 items call for photo evidence, 13 photos in all. A checklist answer without the photo is a claim; the photo is what makes the record worth something in a dispute and lets a reviewer approve work without re-walking the job.
- What most often fails an air handling unit quarterly inspection?
- Filter condition judged through the rack gap instead of pulling one and looking at it. Condensate pan checked in cooling season only, then the heating-season leak finds the ceiling below. Belt tension logged as 'ok' with no deflection check, and the belt fails under the first real load.
- Can I use this checklist in RTI?
- Yes. Start a free RTI workspace, build this list as a checklist, and the Photo Gate holds the submit button until every mandatory item is answered and its photos are attached. Approved inspections roll into a branded turnover package with a tamper evident audit trail.
Run it with the Photo Gate
A checklist nobody can submit half-finished
Load this list into RTI, stick a QR tag on the area it covers, and the submit button stays locked until every mandatory item is answered and the 13 required photos exist. Approved walks roll into a branded turnover package with a tamper evident record behind every line.
See all 508 checklists · 6741 items and 5984 photo requirements in total.