Free checklist
Evaporative cooler quarterly maintenance checklist
A quarterly evaporative cooler 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 IMC (mechanical code), manufacturer's published instructions. 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.
Records and lockout
Water management plan and treatment records reviewed
The site's water management plan covers this unit, and treatment, cleaning and any bacteria results since the last round show action on each out-of-range result.
No photoBlower, pump and controls locked and tagged before panels open
Every source feeding the unit locked by each worker. For run checks: panels on, people clear, locks removed by whoever hung them, run, re-locked before hands go back in.
Media and water distribution
Media fully and evenly wetted with no dry streaks
Water sheeting evenly across the full face of the media, no channeling or dry lanes, media not collapsed, scaled or rotted.
No photoDistribution header and holes flowing clear
Every distribution hole or slot passing water, header not scaled shut, spray or trickle even across the top of the media.
Wetted section sealed so air cannot bypass it
Media pads or spray chamber sealed to the casing, no gaps at the edges, between pads or at access panels where air skips the wetted section.
Sump and bleed
Sump clean and float set to the right level
Sump free of sediment and biofilm, float valve holding level below the overflow, pump submerged and priming.
Pump intake screen, housing and cord or conduit checked in the sump
Intake screen free of scale, slime and debris, pump housing not cracked, cord or conduit and its connection intact and kept clear of the water line.
Bleed or blowdown flowing to drain
Bleed line open and running to an approved drain, not capped or kinked, sump not visibly concentrating or crusting.
Water treatment or scale control device checked
Where the plan calls for a treatment feed, softener or scale control device, it is supplied, in service and not run dry.
No photo
Air side
Blower drive checked: belt and sheaves, or direct-drive mount
Belt not cracked or glazed, tension in the manufacturer's range and sheaves aligned, or the motor mount and wheel set screws tight; worn belts replaced.
Drift eliminators and airflow clear
No water carrying past the eliminators onto the roof or wall, blower moving air, no scale or debris choking the discharge.
Entering and leaving air temperatures read and compared
Temperature drop across the unit compared with last season's readings at similar outdoor conditions, a weak drop flagged for media, wetting or airflow.
Return to service
Panels on, locks removed and unit left running in auto
Access panels and guards back on, locks removed by the person who hung them, unit restarted and left under its controls, not in hand.
Scale, biofilm and wear findings reported to the owner
Dry media, scaled headers, biofilm, drive wear and a weak temperature drop reported to the owner and noted against the water management plan.
No photo
What usually sends this back
The failures are almost always the evidence, not the work
- Media wetted unevenly (dry streaks and channeling) because the distribution header holes are scaled shut.
- Bleed or blowdown plugged or turned off to 'save water,' so the sump concentrates and the media cements up with scale.
- Drift carrying onto the roof or wall, staining the membrane and leaving mineral deposits everyone blames on the roofer.
Verified against
Common questions
6 answers
- What does this evaporative cooler quarterly checklist cover?
- 14 items across 5 sections, covering records and lockout, media and water distribution, sump and bleed, air side, 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 or maintenance tech on the quarterly round through the cooling season.
- When in the schedule should this walk happen?
- Every quarter while the unit is running, because scale and biofilm build fast in warm standing water and a dry patch of media cools nothing.
- Why do these items ask for a photo?
- 10 of the 14 items call for photo evidence, 11 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 evaporative cooler quarterly inspection?
- Media wetted unevenly (dry streaks and channeling) because the distribution header holes are scaled shut. Bleed or blowdown plugged or turned off to 'save water,' so the sump concentrates and the media cements up with scale. Drift carrying onto the roof or wall, staining the membrane and leaving mineral deposits everyone blames on the roofer.
- 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 11 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.