Maintenance Tips for Air Conditioning Systems

If you have any type of mechanical system, such as an air conditioning unit, it will require regular upkeep to maximise efficiency and help it continue to operate as it should. When equipment is well maintained, performance is optimised, running costs are often lower, and breakdown risk is reduced. A planned approach can also help extend service life and avoid avoidable call-outs. If you’d like support setting up a suitable schedule, our service and maintenance options can help.

Summary

This guide is for: homeowners, facilities teams and business owners looking to keep cooling equipment reliable, efficient and safe.

What it covers: routine checks, hygiene and drainage, airflow, electrical safety, and when to bring in a qualified engineer.

• Key takeaway: keep airflow clear (filters and vents) and address water drainage early.
• Key takeaway: Refrigerant work and most electrical checks should be carried out by a competent professional.
• Key takeaway: maintenance frequency depends on use, environment and manufacturer guidance.

For homes and businesses across the wider region, you can also view our South West service areas.

Indoor air quality in your home or workplace matters, and it becomes even more important when you have a cooling system running for long periods. A clean, correctly set up unit supports comfort and humidity control, while a neglected one can circulate dust and odours, struggle to maintain temperature, or contribute to damp issues if drainage is poor.

Routine maintenance checklist

The following points are a sensible minimum for many installations. Always follow the manufacturer’s instructions, and if any step involves electrical work, refrigerant handling, working at height, or access to internal components, use a qualified professional.

• Drain pans and drain lines should be checked and cleaned regularly (often quarterly in many settings). This helps prevent blockages, odours and water damage. Where appropriate, condensate hygiene treatment may be used to reduce biofilm build-up and support reliable drainage.
• Belts (where your system uses them) should be inspected and tensioned routinely. Poor belt condition can reduce airflow and performance, and in some systems, low airflow can contribute to coil icing. If you notice squealing, vibration or reduced output, arrange a professional check rather than running the unit harder.
• Coils should be cleaned at least annually, or more often in dusty or high-use environments. Clean heat-exchanger surfaces support efficient operation, stable temperatures and better airflow. Coil cleaning should be carried out carefully to avoid fin damage.
• Refrigerant levels and pressure should be checked as part of professional servicing. Low charge is often a sign of a leak, and topping up without identifying the cause is unsafe and non-compliant. Refrigerant handling must be carried out by appropriately qualified, F-Gas certified personnel.
• Electrical connections and motors should be inspected periodically for overheating, wear or looseness. Lubrication (where specified by the manufacturer) can reduce friction and help prevent premature component failure. Electrical work should only be completed by a competent engineer.
• All vents and grilles should be kept free from obstruction to maintain airflow. Blocked supply or return paths can reduce comfort and, in some cases, contribute to icing or unnecessary strain on the unit.

Bristol & South West considerations

Local conditions can affect how often you need to check filters, drainage and outdoor components. In this part of the country, you’ll often see a mix of modern developments, older terraces, loft conversions and commercial premises with limited external space, so access and placement matter as much as routine cleaning.

• Humidity and rainfall: mild, damp periods can make condensate management more important, especially where drainage runs are long or routed internally.
• Coastal and roadside exposure: salt air and traffic pollution can increase build-up on outdoor coils, so visual checks and gentle cleaning can be helpful.
• Older buildings: draughts, poor insulation and restricted routing can impact performance, noise perception and where pipework can sensibly run.

If you’re unsure what’s realistic for your property type, a professional assessment is usually the safest next step. Our guide to what an air conditioning site survey involves explains what’s typically checked and why it matters.

When to stop and call a professional

Some checks are not suitable for DIY. Arrange expert support if you notice any of the following:

• Persistent water dripping, staining, musty odours, or repeated drain blockages.
• Ice on the pipework or the indoor coil, or a sudden drop in output.
• Burning smells, tripping electrics, visible scorching, or unusual buzzing from controls.
• Any suspected refrigerant leak (for example, oily residue around joints or repeated loss of performance).

For home upgrades where comfort and layout are key, our home system selection guide is a helpful starting point.