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Cooling Maintenance

Split System Air Conditioning Maintenance Checklist

A maintenance checklist for split system air conditioning units covering indoor and outdoor unit inspection, filter cleaning, refrigerant checks, and drainage — for FM teams and building engineers.

What is a split system maintenance checklist?

A split system air conditioning maintenance checklist is a structured list of the 12 preventive maintenance tasks — covering visual, functional, cleaning, safety and record-keeping checks — that keep a split system air conditioning running safely and reliably. It groups routine checks by frequency, from daily inspections to annual servicing, so FM teams and building engineers can plan and evidence preventive maintenance.

Core split system checks

  • Inspect refrigerant pipework insulation for damage
  • Check condensate drain and pump (if fitted) are clear and functional
  • Clean or replace indoor unit filters
  • Confirm refrigerant label with type and charge weight is present
  • Record system pressures, temperatures, and operational status

What is a split system air conditioning?

A split system air conditioning unit consists of an indoor unit (containing the evaporator coil and fan) and an outdoor unit (containing the compressor and condenser coil) connected by refrigerant pipework. Split systems are one of the most common forms of comfort cooling in commercial buildings, providing cooling and often heating via a reversible refrigerant cycle.

Typical Split system maintenance checklist

A practical starting point for planned preventive maintenance. Always refer to the manufacturer's O&M manual and site-specific requirements.

Visual Checks

  • Inspect refrigerant pipework insulation for damage
  • Check for oil staining around pipe joints indicating refrigerant leaks
  • Inspect electrical isolator and connections

Functional Checks

  • Check condensate drain and pump (if fitted) are clear and functional
  • Verify indoor fan operates on all speed settings
  • Check outdoor fan motor operation
  • Verify remote controller and thermostat function correctly

Cleaning & Housekeeping

  • Clean or replace indoor unit filters
  • Clean indoor unit evaporator coil and housing
  • Inspect outdoor condenser coil and clean of debris, leaves, or dirt

Safety Checks

  • Confirm refrigerant label with type and charge weight is present

Record Keeping

  • Record system pressures, temperatures, and operational status

Typical maintenance frequency

Suggested intervals for split system air conditioning maintenance. Actual frequencies should follow manufacturer guidance and site-specific risk assessments.

Monthly

  • Clean indoor unit filters
  • Check condensate drain

Quarterly

  • Clean condenser coil
  • Check refrigerant pipework
  • Verify controller operation

Annually

  • Full system check including pressures and temperatures
  • Electrical inspection
  • F-Gas leak check
  • Check reversing valve for heat pump models

Common faults and issues

Issues to be aware of when maintaining split system air conditioning equipment.

Blocked indoor filters causing ice formation on the evaporator coil
Condensate pump failure leading to water overflow from the indoor unit
Dirty outdoor condenser reducing cooling performance, especially in summer
Refrigerant charge loss over time causing gradual decline in performance
Failed PCB or controller board on the indoor unit

Safety and compliance notes

Key safety considerations for split system air conditioning maintenance. This is general guidance only — always follow OEM instructions, statutory requirements, and your organisation's safe systems of work.

Only F-Gas certified engineers should handle refrigerant circuits
Isolate both indoor and outdoor units electrically before maintenance
Outdoor units at height require safe access and fall protection
Log all refrigerant handling activities for F-Gas compliance
How PM Assist helps

Managing Split system documentation with PM Assist

PM Assist helps FM and building operations teams search their O&M manuals and building drawings in seconds. Upload your split system air conditioning documentation and ask questions like “What is the rated cooling capacity?” or “When was the last F-Gas leak check?” — and get source-cited answers instantly.

See PM Assist answer questions about a real split system manual — try the live demo, no signup needed.

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Frequently asked questions

Manage your building documentation with AI

PM Assist gives FM teams instant access to O&M manuals, drawings, and maintenance knowledge — all searchable with AI.

  • Upload and organise building documentation
  • AI-powered search across all your manuals
  • Source-cited answers for maintenance queries
  • Team collaboration and access control
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