What does this makeup air unit (mau) quarterly checklist cover?

14 items across 5 sections, covering running checks, air side and filters, fan and drive, dampers and interlock, 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 kitchen-exhaust service tech on the quarterly rooftop round.

When in the schedule should this walk happen?

Every quarter, run on the same visit as the kitchen exhaust fan so the supply-and-exhaust pair is checked together, not separately.

Why do these items ask for a photo?

8 of the 14 items call for photo evidence, 10 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 a makeup air unit (mau) quarterly inspection?

Filters loaded solid with cooking grease and street dust, so the unit can't deliver the air the hood is pulling and the kitchen goes negative. Interlock never actually watched: the tech assumes the MAU starts with the hood instead of standing at the unit while the exhaust fan is switched on. Outside-air damper stuck part-closed on a seized linkage and logged as 'operating' because nobody watched the blades move.

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.

Free checklist

Makeup air unit (MAU) quarterly maintenance checklist

A quarterly makeup air 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 IMC, manufacturer's published instructions. Confirm the edition your authority having jurisdiction has adopted.

Start free with this checklist Download as PDF

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 checks

Discharge temperature read against setpoint on the running unit
Leaving-air temperature at the controller or with a probe compared with its setpoint in the current mode, a spot check ahead of the annual test across the burner range.
Burner light-off and flame watched on a heat call, gas units
On direct or indirect gas units, ignition, flame proving and a steady, even flame watched through the sight port on a heat call; electric heat units skip this.
No photo
Every MAU feed locked and tagged before doors open
Separate electric heat included, gas shut and tagged on gas units, start tried; powered checks run under the procedure's temporary release (clear, guards on, locks off by their owner), then re-locked.

Air side and filters

Filters pulled and checked against the hood's demand
Filter faces checked for grease loading and gaps at the racks, replaced when blinded, no air bypassing around a short filter.
Intake hood and screen clear
Outdoor intake screen free of leaves, lint and grease film, no exhaust discharge recirculating back into the intake.
Freeze protection sensor and setpoint checked
Low-limit sensor mounted in the discharge airstream and its setting matched to the controls drawing or manual, on units fitted with one; the trip test is on the annual.
No photo

Fan and drive

Belt tension and condition checked
Belt free of glazing and cracking, correct deflection, sheaves aligned, no belt dust piled under the drive.
No photo
Motor and fan run observed
Motor runs without overheating or odd bearing noise, fan wheel free of grease buildup and turning true.
Fan bearings greased to the manufacturer's schedule
Grease fittings given the type and amount in the manual with purged grease wiped off, sealed bearings left alone, and any roughness felt by hand reported.
No photo

Dampers and interlock

Outside-air damper cycled through full travel
Blades driven fully open and closed, linkage tight, actuator following the command with no stall.
Exhaust interlock proven by switching the hood on
MAU proves and starts when the kitchen exhaust fan is energized and stops when it stops, watched at the unit and not assumed.

Return to service

Doors latched, guards on and locks removed by their owner
Access doors latched, belt guard refastened, each lock and tag removed by the tech who hung it, and the gas valve reopened on gas units.
Unit control left in auto so the hood interlock governs
Hand-off-auto selector or drive keypad returned to auto, not left in hand where the unit runs without the hood, and the unit seen running again before the tech leaves.
No photo
Quarterly findings and parts needed sent to the owner
Filter loading, belt wear, burner observations and the discharge reading sent to the owner, with parts needed ahead of the annual heat-season service.
No photo

What usually sends this back

The failures are almost always the evidence, not the work

Filters loaded solid with cooking grease and street dust, so the unit can't deliver the air the hood is pulling and the kitchen goes negative.
Interlock never actually watched: the tech assumes the MAU starts with the hood instead of standing at the unit while the exhaust fan is switched on.
Outside-air damper stuck part-closed on a seized linkage and logged as 'operating' because nobody watched the blades move.

Verified against

IMC (mechanical code)

Common questions

6 answers

What does this makeup air unit (mau) quarterly checklist cover?: 14 items across 5 sections, covering running checks, air side and filters, fan and drive, dampers and interlock, 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 kitchen-exhaust service tech on the quarterly rooftop round.
When in the schedule should this walk happen?: Every quarter, run on the same visit as the kitchen exhaust fan so the supply-and-exhaust pair is checked together, not separately.
Why do these items ask for a photo?: 8 of the 14 items call for photo evidence, 10 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 a makeup air unit (mau) quarterly inspection?: Filters loaded solid with cooking grease and street dust, so the unit can't deliver the air the hood is pulling and the kitchen goes negative. Interlock never actually watched: the tech assumes the MAU starts with the hood instead of standing at the unit while the exhaust fan is switched on. Outside-air damper stuck part-closed on a seized linkage and logged as 'operating' because nobody watched the blades move.
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.

Related checklists

Makeup air unit (MAU) AnnualMakeup air unit (MAU) annual maintenance checklistHeat section, measured supply airflow against exhaust, bearings and the full control sequence on the annual service15 items11 photos

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 10 required photos exist. Approved walks roll into a branded turnover package with a tamper evident record behind every line.