A chiller rarely fails without warning — it drifts. The condenser approach creeps up as tubes foul, oil pressure sags, a sensor falls out of calibration, and efficiency bleeds away weeks before anything trips. Preventive maintenance is how you catch that drift while it's still a reading on a log, not a compressor on the floor. This checklist is organised the way a chiller is actually built — by subsystem, with how often each check is due — so nothing on the machine gets skipped. OXMAINT AI — the AI-powered maintenance management software — puts every one of these tasks on a schedule and raises the work order when it's due.
HVAC · Chiller Preventive Maintenance · Inspection & PM Checklist · 2026
Chiller Preventive Maintenance Checklist
Work through the chiller the way it's built — compressor, condenser, evaporator, refrigerant, electrical and safety — each task tagged with how often it's due. The OXMAINT AI maintenance management software keeps every interval on schedule so no check quietly lapses.
Compressor
Condenser
Refrigerant
Controls
By subsystem
organised the way the machine is built, so nothing gets missed
Every interval
daily readings through annual teardowns, each on its own cadence
Approach temp
the early tell-tale of fouling, trended instead of discovered
Logged
readings captured per chiller, so drift shows before it trips
Why a Subsystem Checklist Beats a Walk-Around
A chiller is five systems working as one, and each fails in its own way — fouling in the condenser, oil in the compressor, charge in the refrigerant circuit. Checking by subsystem means the quiet failures get caught, not just the loud ones; book a demo to see chiller PM by subsystem in OXMAINT AI.
Catch drift early
Rising approach temperature and falling oil pressure show on the log weeks before a trip.
Protect efficiency
A fouled condenser or low charge quietly raises energy use long before it raises an alarm.
Keep it safe
Pressure cutouts, flow switches and relief devices only protect you if they're proven on a schedule.
Extend asset life
Clean tubes, good oil and correct charge spare the compressor the wear that ends chillers early.
The Chiller PM Checklist
Six subsystems, each with its own checks and intervals. The chip on each line shows how often it's due. Run through them per chiller on their cadence; start free and put every one of these on a plan in OXMAINT AI.
Frequency
DDaily
WWeekly
MMonthly
QQuarterly
AAnnual
A Daily Reading Is Worthless If Nobody Trends It.
Chiller drift lives in the readings — approach temperature, oil pressure, motor amps — and a clipboard buries it. The OXMAINT AI maintenance management software captures each reading against the chiller and trends it, so a slow slide surfaces as a signal instead of a surprise trip.
The Readings That Warn You First
Three numbers tell you a chiller is losing health long before it faults — watch these and the checklist becomes early warning, not just routine. Catch any one moving and dig in; book a demo to see these trended in OXMAINT AI.
Condenser approach ↑
The gap between refrigerant and leaving water temperature widening is the classic sign of fouling or scale on the tubes.
Oil pressure ↓
A sagging differential points to oil, filter or bearing trouble — act before it becomes a compressor fault.
Evaporator approach ↑
A rising evaporator approach can flag low charge or fouling, both of which cost capacity and efficiency.
How OXMAINT AI Runs Chiller PM
A checklist only protects the chiller when the tasks actually run and the readings get seen. Here's what the OXMAINT AI maintenance management software brings to chiller preventive maintenance; start free and keep every chiller on a plan in OXMAINT AI.
Interval-based schedules
Daily, weekly, monthly, quarterly and annual tasks each on their own cadence per chiller, so none lapses.
Digital reading capture
Pressures, temperatures and amps logged on a device against the asset, legible and complete every time.
Reading trends
Approach temperature, oil pressure and motor load trended over time, so slow drift becomes a visible signal.
Auto work orders
A due task or an out-of-range reading raises a work order with the chiller, the finding and the parts attached.
Safety checks on record
Cutouts, flow switches and relief tests logged with dates, so the protections are proven, not assumed.
Full chiller history
Every reading, task and repair on record per asset, so recurring faults and worn chillers stand out.
“
Our chiller PM was a laminated sheet that got ticked whether or not the readings were taken. We moved it onto schedules by subsystem and started logging approach temperature daily. Three weeks later the condenser approach on the lead chiller was climbing — we pulled and brushed the tubes before it ever tripped on high head. That's the shift: we fix fouling now, instead of chasing a chiller that's gone down on the hottest day of the year.
Chief Engineer · Commercial Cooling Plant
Frequently Asked Questions
What should a chiller preventive maintenance checklist cover?
Every subsystem: the compressor (oil, vibration, run hours), the condenser and its water flow (approach temperature, treatment, tube cleaning), the evaporator, the refrigerant circuit (charge, superheat, leaks), the electrical and controls, and the safety devices. Organising by subsystem makes sure the quiet failures get caught, not just the obvious ones.
Start free and schedule the full checklist.
How often should a chiller be serviced?
On mixed intervals: operators log key readings daily, do visual and flow checks weekly to monthly, test controls and safeties quarterly, and carry out the deep work — tube cleaning, oil analysis, sensor calibration, relief inspection — annually, usually before peak season. The exact cadence depends on the chiller type, duty and manufacturer guidance.
Why does condenser approach temperature matter so much?
Approach — the gap between refrigerant temperature and leaving water temperature — widens as tubes foul or scale. It's the earliest, cheapest warning of lost efficiency, visible on a daily log long before the chiller trips on high head pressure. Trending it is one of the highest-value things you can do.
Book a demo to see it trended.
What are the warning signs a chiller needs attention?
Rising approach temperatures, falling oil pressure, abnormal noise or vibration, short-cycling, a sight glass showing bubbles or moisture, climbing motor amps, and more frequent safety trips. Most of these show on the readings first — which is exactly why logging and trending beat a visual walk-around.
How does a CMMS help with chiller maintenance?
It puts each task on its own interval per chiller, captures readings digitally against the asset, trends them so drift surfaces early, turns a due task or an out-of-range reading into a work order automatically, and keeps every reading, task and safety test on record — so chiller care is scheduled and proven instead of remembered.
Keep Every Chiller Running Before Peak Season Tests It.
Put chiller PM on a plan with the OXMAINT AI maintenance management software — interval-based schedules by subsystem, digital reading capture, trended approach and oil pressure, automatic work orders, and safety tests on record. Catch the drift on the log, not the compressor on the floor.
