VRF system quarterly maintenance checklist

Outdoor coil and fans clear and running

Condenser coil faces free of lint, leaves and cottonwood on all sides, fans spinning freely and quiet, clearances around the unit maintained, no fault standing on the outdoor board.

Outdoor unit stand, mounts and fixings sound

Stand, dunnage or pad solid with no rust-through, anti-vibration mounts seated, hold-downs tight and the unit not walking or rocking while the compressors run.

Refrigerant valve boxes dry and condensate draining

Branch controller and refrigerant valve boxes free of oil residue at the connections, insulation intact, and any condensate drain from the box flowing clear with no back-up above the ceiling.

Branch joints and headers checked for oil at the access points

Y-branch joints and headers reached through the ceiling access on the walk looked at with a light for oil staining or frost, insulation closed back over them.

Heat recovery branch boxes quiet through a mode changeover

On heat recovery systems, the box listened to while nearby heads switch between heating and cooling, no valve chatter or refrigerant hammer and no port fault posted.

Walked heads turned off and fans at rest before grilles drop

Head stopped from the central or local controller and its fan fully stopped before the return grille or filter panel is lowered, with the occupant told first.

Indoor filters and drains checked at a sample of heads

Filters at the walked heads cleaned or replaced, pans draining, condensate pumps cycling quiet where fitted, no staining on the wall or ceiling below a head.

Drain pump float trip shown as a fault at the controller

Where a head has a built-in drain pump, water added to its pan until the float stops the head and the fault posts at the controller, then cleared once drained.

All indoor units reporting on the controller

Central or remote controller showing every addressed head online and answering, no communication error or missing unit, heat and cool commanded at a sample head to confirm changeover.

Refrigerant leak detection present and powered where required

Where leak-detection sensors are required for the room's refrigerant concentration, the sensor is in place, powered and not in fault or bypass.

Sensed room temperature checked against a thermometer

At the sample heads, the room temperature the controller shows compared with a reference thermometer at the sensor location, a drifted sensor or thermistor noted.

Error history read at the central controller or service tool

Stored errors scrolled by address and date, repeat codes on the same head or outdoor unit noted, and anything still active written up for follow-up.

Schedules and setpoint limits match the owner's settings

Operating schedules, setback, setpoint limits and local-control lockouts on the central or local controllers read against the owner's settings, holiday dates current.

Test commands cleared and heads back on their schedules

Heads commanded for the changeover or float tests returned to their mode, setpoint and schedule, grilles latched and no manual override left at any controller.

Findings logged against each system and head address

Filter, drain, error code and sensor findings entered by refrigerant system and head address, so the annual knows which heads and branch boxes to open.