What Actually Happens During a Chiller Service?

Most understand the need for regular servicing, but not what it entails. Servicing goes beyond checking that the equipment reaches its set temperature. It gives engineers an opportunity to assess conditions, investigate potential problems and identify anything that could affect future operation.

The exact work depends on the chiller, its operating conditions and the agreed service scope. Here's what a typical visit may involve.

Before the chiller service begins

A good service starts with the equipment's history. Previous reports highlight recurring faults or components that needed attention, painting a clearer picture for the engineer deciding what to investigate.

Feedback from operators is even more useful. Sometimes occasional alarms, unusual noises or difficulty maintaining temperature will decide to miraculously fix themselves during a short inspection but return almost immediately after, or only under certain production conditions.

How the equipment is used provides even more insight. A chiller running continuously in a demanding manufacturing environment will experience different operating conditions from one used intermittently.

Where cooling is critical to production, any necessary shutdowns or isolation must be coordinated with the site. An initial visual inspection can then identify obvious concerns, such as leaks, damaged insulation or restricted airflow, before more detailed checks begin.

Checking the mechanical and refrigeration components

Refrigeration circuits are essential to removing heat, so engineers need to establish whether the main components are operating as expected.

The compressor is a key part of this. Unusual vibration, noise or abnormal electrical running characteristics indicate developing problems. Condenser condition is also important, particularly on air-cooled units, where accumulated dirt or restricted airflow can make it harder to reject heat. Fan and motor wear or poor operation can affect performance even when other refrigeration components are functioning correctly.

Engineers assess refrigerant pressures and temperatures to understand how the circuit is operating. These readings need to be considered alongside the process load and ambient conditions, rather than treated as isolated indicators of a fault.

Where refrigerant leak checks or work on the refrigerant circuit is required, appropriately qualified personnel must carry them out in accordance with applicable F-Gas requirements.

The purpose of these checks is identifying deterioration or abnormal operation before it develops into a more serious problem.

Inspecting the water and glycol circuit

Even when refrigeration equipment is working correctly, poor fluid circulation prevents cooling from reaching the process effectively.

Pump operation, flow and pressure readings can help establish whether the circuit is circulating fluid as required. A blocked strainer or restriction in the pipework may reduce cooling performance without causing an obvious fault in the refrigeration system.

Leaks can also develop gradually around pipework connections, valves and seals. Whilst relatively small at first, these still require attention.

For glycol systems, concentration is another consideration. It needs to provide suitable freeze protection for the operating temperatures without unnecessarily affecting circulation and heat transfer.

Insulation condition can also influence performance. Missing or damaged insulation allows unwanted heat into the chilled-fluid circuit and may lead to condensation.

These checks help establish whether the wider system is delivering the cooling produced by the chiller, rather than focusing solely on the refrigeration equipment.

Electrical checks and system controls

A mechanically sound chiller can still operate poorly if its electrical components or controls aren't functioning correctly.

Connections and switching components may deteriorate over time, causing overheating or intermittent faults. Appropriate electrical inspections can identify problems that aren't obvious during everyday operation.

Controls also play an important role in maintaining stable process temperatures. If a sensor provides an inaccurate reading, the chiller may respond incorrectly even though its mechanical components are working as intended.

Stored alarms can offer further clues. An engineer might find the equipment running normally during the visit, while its alarm history reveals previous pressure, flow or temperature issues.

Where the chiller operates alongside external pumps or process controls, their interaction also needs consideration. The aim is to establish whether the equipment responds correctly to demand and whether its protective functions are operating as intended.

Testing performance and recording the findings

Once the relevant inspections and maintenance work are complete, operating checks help establish how the chiller is performing.

Leaving-water and return-water temperatures provide information about the cooling circuit, particularly when considered alongside flow and process demand. Refrigeration readings and electrical operating measurements may offer further insight.

However, results need context. A chiller running under a light load won't behave the same way as it does during peak production.

Previous service records are valuable here. Comparing readings over time usually reveals gradual changes that wouldn't stand out during a single visit.

Engineers should also record any adjustments made and identify issues requiring further investigation. Although servicing cannot eliminate the possibility of breakdowns, it provides a clearer understanding of the equipment's condition.

What happens after the chiller service?

The service report brings the findings together, documenting the work completed, relevant operating readings and any concerns identified.

Not every issue requires immediate repair. Some findings may call for monitoring or planned maintenance, while others need more urgent attention. Where further work is recommended, the customer should understand what has been found and why it matters.

Over time, these records help build a picture of the chiller's condition and inform future maintenance decisions. Service intervals should take account of manufacturer guidance, operating conditions and the importance of the equipment to production.

At Nexus Cooling, our planned preventative maintenance programmes are tailored to how equipment is used and the environment in which it operates. We also provide reactive repairs and system optimisation where additional work is needed.

Chiller servicing with Nexus Cooling

A chiller service provides more than a snapshot of whether equipment is running. By examining its operation and condition, engineers can identify developing problems and recommend work that supports continued reliability.

Nexus Cooling provides planned maintenance, repairs and optimisation for industrial cooling systems, including the nVent HOFFMAN chillers we supply.

Need to arrange a chiller service? Speak to Nexus Cooling about maintaining your equipment and planning servicing around your operational requirements.