Gas detection system annual maintenance checklist

Occupants, monitoring and the owner told before test gas is applied

Owner, zone occupants, any monitoring company and kitchen or plant staff told test gas can trip alarms, fans and shutoffs, and when outputs will be held.

Controller event log reviewed for the year

Alarm, fault and inhibit events since the last annual read or exported from the controller, each alarm matched to a cause and repeat faults flagged.

Every sensor accounted for and matched to the panel and area served

Field head count matches the controller, each zone still covers the space it serves, remodeled areas checked for gaps in coverage.

Mounting height measured at each head against the design

Measured, not judged by eye: low for heavier-than-air gases, high for lighter-than-air gases such as natural gas, and CO heads at the height the design shows.

Heads cleaned and inspected

Grease, dust and moisture cleared from each head per the manufacturer, cell housings intact, no corrosion at terminals.

Sensor cell install and end-of-life dates recorded at each head

Beyond the quarterly read: each cell's date label compared with the manufacturer's rated life, cells at or near end of life replaced and the new date labeled.

Calibration gas cylinder label and expiry date photographed

Certified cylinder's gas and concentration match what the manufacturer's method calls for at each sensor, the cylinder is in date and its regulator suits it.

Bump test and calibration by the tech observed and logged

Test gas applied by the certified tech, response and setpoints recorded, sensors reading zero on clean air after calibration.

Inhibit or calibration mode cleared on every channel

Any inhibit, bypass or calibration mode the manufacturer's method used is cleared, the controller shows normal monitoring and every output is armed again.

Calibration record on file with as-found and as-left readings

The certified tech's record lists each sensor, the gas cylinder used, as-found and as-left readings and the next due date, filed with the owner.

Relay assignments compared with the design sequence

Controller relay outputs, alarm levels and delays match the design sequence of operations, with no output reassigned or disabled since commissioning.

Alarm-to-ventilation sequence proven for each zone

Each detection zone driven to alarm confirms its exhaust fan, dampers, alarms and any shutoff respond, then returns to normal.

Shutoffs reopened, outputs reset and panel back to normal

Any shutoff valve reopened and appliances relit by a qualified person, fans and dampers back to their normal sequence, controller showing normal with no faults.

Owner and monitoring told the system is back, report sent

Owner and monitoring told detection is back in service, and the inventory, replaced cells, calibration record and interlock results sent to the owner.