What does this gas detection system quarterly checklist cover?

15 items across 4 sections, covering sensors and heads, controller and alarms, ventilation interlock, return to service. 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 controls or mechanical tech on the quarterly round; the field observes and documents, calibration stays with the certified tech.

When in the schedule should this walk happen?

Every quarter, because a sensor in a parking area or kitchen sits in dust, grease and moisture and drifts long before anyone smells the problem.

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 a gas detection system quarterly inspection?

Panel showing a fault or a sensor past its calibration-due date that everyone had learned to ignore. A refrigerant or CO head painted over, wrapped, or mounted where a later remodel walled it off. The gas alarm no longer starts the exhaust fan or drops the makeup-air damper, so detection happens but nothing ventilates.

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

Gas detection system quarterly maintenance checklist

A quarterly gas detection system 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), the applicable building code, 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.

Sensors and heads

Design sensor layout and setpoint schedule on hand for the round
Current design or commissioning drawings showing each head's location, height, target gas and alarm setpoints, so the field can be compared to them.
No photo
Each sensor located, clear and mounted at the right height for its gas
Heads unobstructed and undamaged, low for heavier-than-air refrigerant, in the breathing zone for CO, none painted or wrapped.
Calibration-due status read at each sensor or the panel
Sensor life and calibration-due dates within range, none expired, any past-due head flagged for the tech.
Target gas on each head's label matched to the area it serves
Label shows the gas the design calls for there: the refrigerant in use in the machinery room, CO or nitrogen dioxide in the garage, combustible gas at appliances.
Sensing face, filter and splash guard checked at each head
Sensor filter or dust cap clean and fitted, any splash guard or hood the manufacturer supplies in place, no grease, paint or overspray film on the sensing face.
Head mounting, wiring entries and conduit secure
Head tight to its wall or column, cable or conduit secured at the entry, no damage from vehicles, carts or cleaning equipment since the last round.
Local reading at each head compared with the controller
Head status light normal and any local display reading the same value the controller shows for that channel, with a mismatch flagged for the tech.

Controller and alarms

Panel in normal state with no active faults
Controller powered, no trouble or fault indication, alarm setpoints displayed, event log free of unresolved alarms.
Alarm setpoints on each channel compared with the design
Each channel's alarm levels match the design schedule or commissioning record, none raised or disabled to quiet nuisance alarms.
Horns, strobes and entrance signs intact at each monitored area
Horns and strobes undamaged and unobstructed, warning signs at the entrances legible, so people outside can tell the space is in alarm.

Ventilation interlock

Occupants, monitoring and the owner told before the test alarm
Owner, occupants of the zone, any monitoring company or BAS operator and kitchen or plant staff told the alarm will sound, start fans and may close gas shutoffs.
No photo
Alarm signal drives the exhaust fan and dampers
On a simulated or test alarm the exhaust fan starts and makeup-air/relief dampers move to their ventilation position, audible/visual alarms activate.
Shutoff valve or equipment stop observed on the test alarm
Where the design has a gas shutoff valve or equipment shutdown on alarm, it closes or stops on the test signal as the sequence of operations describes.
No photo

Return to service

Controller reset and every output back to normal
Panel showing normal, fans and dampers back to their normal sequence, any manual-reset shutoff reopened and appliances relit by a qualified person.
Owner and monitoring told the test is over, findings reported
Owner and monitoring told the system is back to normal; blocked heads, setpoint mismatches and failed outputs sent to the owner and the certified tech.
No photo

What usually sends this back

The failures are almost always the evidence, not the work

Panel showing a fault or a sensor past its calibration-due date that everyone had learned to ignore.
A refrigerant or CO head painted over, wrapped, or mounted where a later remodel walled it off.
The gas alarm no longer starts the exhaust fan or drops the makeup-air damper, so detection happens but nothing ventilates.

Verified against

IMC (mechanical code)

Common questions

6 answers

What does this gas detection system quarterly checklist cover?: 15 items across 4 sections, covering sensors and heads, controller and alarms, ventilation interlock, return to service. 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 controls or mechanical tech on the quarterly round; the field observes and documents, calibration stays with the certified tech.
When in the schedule should this walk happen?: Every quarter, because a sensor in a parking area or kitchen sits in dust, grease and moisture and drifts long before anyone smells the problem.
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 a gas detection system quarterly inspection?: Panel showing a fault or a sensor past its calibration-due date that everyone had learned to ignore. A refrigerant or CO head painted over, wrapped, or mounted where a later remodel walled it off. The gas alarm no longer starts the exhaust fan or drops the makeup-air damper, so detection happens but nothing ventilates.
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.

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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.