Chiller Maintenance Checklist for Dubai Buildings

Most chiller trips show up in the log sheet weeks before they happen. The condensing pressure creeps up, the approach temperature widens, or the amps drift at the same load. This checklist covers what to log every day on an air-cooled or water-cooled chiller in a Dubai building, and what to check monthly, quarterly, annually and every few years.

Use it alongside your chiller’s installation, operation and maintenance (IOM) manual. Where the manual sets a different interval, follow the manual. For the full service scope, including breakdown repair and compressor overhauls, see our chiller maintenance service.

Who does what on a chiller maintenance plan

Whoever takes the readings, they all go on the same sheet, so the trend stays in one place.

Daily chiller log sheet

Take readings at the same time each day and at a similar load, so you compare like with like. A BMS trend can replace the clipboard, but someone still has to look at it.

Weekly walk-round

• Look for oil stains and frosting on pipework, valves and joints.
• Listen for new noise or vibration at compressors, pumps and fans.
• Check pump seals for weeping.
• Note the strainer pressure gauges on the chilled and condenser circuits.
• On air-cooled chillers, look at the condenser coil faces for sand build-up and anything stored against the unit.
• On water-cooled plant, check that the chemical dosing pumps are running and the tanks aren’t empty.

Monthly chiller maintenance checklist

Quarterly service checklist

This is the contractor’s visit. Each item should end up as a number on the report, not just a tick.

• Superheat and subcooling for each circuit, compared with the nameplate data
• Refrigerant charge assessment and leak test
• Compressor amps, voltage balance and an oil acid test
• Safety devices trip-tested: high pressure, low pressure, freeze protection, flow switch and oil pressure
• Controller diagnostics, with sensors checked against a reference thermometer
• Air-cooled condenser coils cleaned
• Water strainers cleaned. Trane’s CenTraVac manual, for example, sets this at every three months.
• Vibration readings on compressor, motor and pump bearings
• Starter or VFD terminations, cooling fans and contactor condition

Annual shutdown checklist

• Oil sample sent to a lab for moisture, acid and wear metals. Several manufacturers now recommend changing the oil only when the analysis calls for it.
• Motor winding insulation resistance measured and compared with last year’s figure.
• Condenser tubes inspected with the waterbox heads off, and brushed if fouled. Chemical descaling should always be followed by mechanical cleaning, flushing and inspection.
• Evaporator inspected.
• Temperature and pressure sensors calibrated.
• Flow switches and interlocks proved.
• Full leak test of the refrigerant circuit.
• Waterbox coatings and sacrificial anodes inspected.
• Electrical panels checked under load, including terminations.

Every three to five years

• Eddy current test of condenser and evaporator tubes. Trane recommends one every three years on its CenTraVac chillers, and more often on critical process plant. The first test after commissioning becomes the baseline.
• Evaporator tube clean on closed chilled-water circuits, which Trane puts at normally every three years.
• Compressor inspection at the manufacturer’s run-hour interval.
• Refrigerant review on older plant. R-22 is being phased out under the Montreal Protocol, and after 2030 the UAE’s group keeps only a small servicing allowance. Plan for it before a major repair forces the decision.

Cooling tower and water-side items

On a water-cooled chiller, half the checklist lives outside the plant room, because condenser tubes only stay clean if the tower water does. Check the basin, fill and drift eliminators, clear the nozzles, and confirm that dosing, bleed-off and conductivity control are working. File the water treatment reports with the chiller log.

Under Dubai’s Al Sa’fat green building system, cooling towers must be periodically cleaned, disinfected and checked under Dubai Municipality’s Legionella guidelines. Water sampling is done by a DM-approved company, and the results are kept on site with the maintenance records. Towers in new buildings also need a separate meter on their water supply and a daily water-use log. The tower side is covered on our cooling tower maintenance page.

Five log trends that mean call an engineer

1. Condenser approach rising. Tubes are fouling or scaling, or there is air in the circuit. Trane estimates a 1°C rise in condenser temperature adds about 2% to operating costs.
2. Evaporator approach widening while suction pressure falls. The usual causes are low charge or a fouled or oil-logged evaporator.
3. Temperature difference across the evaporator shrinking at full load. Too much water is flowing for the load, often because of a control valve problem out in the building, and the chiller can’t load properly.
4. Amps rising at the same load. Look at the supply, the contactors and the motor, or a compressor working against higher head pressure.
5. Oil acid positive or wear metals climbing. This points to moisture in the circuit, winding stress or bearing wear. It is the early warning that comes before a compressor overhaul.

Keep the paperwork in one place

A chiller with a clean paper trail is easier to maintain, easier to hand over and easier to claim warranty on. Keep these together:

• daily logs or BMS trend exports
• contractor service reports
• oil analysis and eddy current reports
• water treatment and Legionella results
• a record of refrigerant added, in kilograms, with the date and the leak that was found.

Having the checklist run for you

If you’d rather hand the checklist over, our chiller maintenance service starts with an initial audit at AED 1,500–4,500, depending on chiller size and complexity. The fee is credited against any contract you sign. We set up the log sheet and schedule, then carry out the quarterly and annual work. If the site also has AHUs, FCUs and cooling towers, a commercial AMC puts all of it on one contract. Send the chiller make, model and tonnage on WhatsApp to +971 52 423 0419.

Chiller checklist questions

Q: How often should chiller readings be logged? A: At least once a day, at the same time and at a similar load, so readings compare like with like. Critical process plant and large central plant are often logged every shift or trended continuously on the BMS. A single reading tells you little. A month of readings shows a fouling condenser or a slow leak.

Q: What is chiller approach temperature? A: It is the gap between the refrigerant’s saturated temperature and the water leaving the heat exchanger. Condenser approach compares condensing temperature with leaving condenser water. Evaporator approach compares leaving chilled water with saturated suction temperature. Both are recorded at commissioning. A steady rise above that figure points to fouled tubes, low charge or air in the circuit.

Q: How often should chiller condenser tubes be cleaned? A: Inspect them every year and clean them when the condenser approach shows fouling, rather than on a fixed date. On plant with a cooling tower and weak water treatment, that can mean every year. On well-treated systems it may be less often. Chemical descaling should always be followed by mechanical brushing, flushing and inspection.

Q: Do chillers need an oil change every year? A: Not always. Several manufacturers, Trane among them, recommend an annual oil analysis and changing the oil only when it shows moisture, acid or wear metals. The analysis also works as a diagnostic, flagging compressor wear or moisture in the circuit early. Always use the oil type specified for your chiller and refrigerant.

Q: What is an eddy current test, and do I need one? A: It is a non-destructive test that runs a probe through each heat-exchanger tube to find wall thinning, pitting and cracks before a tube fails and lets water into the refrigerant circuit. Trane recommends it every three years on its water-cooled centrifugal chillers, and more often on critical process plant. It matters most where tubes see open cooling tower water.

# 3. Internal links

Optional related-reading links for the sidebar or the end of the post: /facility-maintenance-kpis-every-dubai-property-manager-should-track/ and /what-does-an-amc-contract-actually-cover-a-dubai-building-owners-breakdown/.

# 4. Flags for Sal

1. The only price used is the live chiller audit bracket (AED 1,500–4,500, credited against any contract). No other prices appear.
2. “Legionella sampling … a Dubai Municipality-approved company” follows Al Sa’fat 406.01. This matters because the live cooling tower page implies Samra does the testing.
3. The daily-meter and water-log rule (Al Sa’fat 603.02 C) applies to cooling towers in new buildings. The copy says “towers in new buildings”.
4. Nothing in this post claims coverage outside Dubai.

# 5. Sources checked (for Sal and Ashish, not for publishing)

• Trane CVHE/CVHF/CVHG CenTraVac IOM, “Recommended maintenance” table: daily logs; clean all water strainers every 3 months; annual oil analysis (“change the oil only if indicated by the oil analysis”), condenser tube inspection and winding insulation check; non-destructive tube test every three years, more often on critical process equipment; closed evaporators normally cleaned every three years; chemical cleaning followed by mechanical cleaning, flushing and inspection. https://www.trane.com/content/dam/Trane/Commercial/global/products-systems/equipment/chillers/water-cooled/centrifugal-liquid/earthwise-ctv-simplex/CVHE-SVX02P-EN_10172019.pdf
• Trane automatic tube cleaning (“a 1°C increase in condenser temperature can cause a 2% increase in operating costs”): https://trane.eu/uk/services/service-details.html?serviceId=313
• Al Sa’fat Dubai Green Building Evaluation System (text read). 406.01: cooling towers periodically maintained, cleaned, disinfected and checked under DM Legionella guidelines; “Specialized companies approved by Dubai Municipality must do water tests and sampling”; results kept on site. 603.02 C, for new buildings: “A separate totalizing meter must be fitted on the water supply to individual cooling towers and a daily log of water use must be kept.” https://www.wkcgroup.com/wp-content/uploads/2023/04/Al-Safat-Dubai-Green-Building-Evaluation-System.pdf. Official copy (blocked automated fetch): https://www.dm.gov.ae/wp-content/uploads/2020/11/Safat-English.pdf
• DM technical guidelines list (TG 44, Legionella in water systems): https://www.dm.gov.ae/municipality-business/technical-guidelines-list/
• Montreal Protocol Decision XIX/6, Article 5 HCFC schedule (97.5% by 2030, servicing tail to 2040): https://ozone.unep.org/treaties/montreal-protocol/meetings/nineteenth-meeting-parties/decisions/decision-xix6-adjustments-montreal-protocol-regard-annex-c-group-i-substances. UAE Article 5 status: https://ozone.unep.org/countries/profile/are