Air conditioning systems — like boilers and other mechanical equipment — benefit significantly from regular servicing. An annual service maintains efficiency, prevents the majority of breakdowns, keeps your installation legally compliant (for commercial premises), and extends the working life of the system. Here is exactly what our annual service includes and why each element matters.
What’s Included in Our Annual Service
Filter Inspection and Clean
The air filters in the indoor unit are the first line of defence against dust accumulation on the evaporator coil. We remove, inspect and clean the filters — or replace them if they are damaged. A blocked filter reduces airflow, reduces cooling efficiency and can cause the evaporator coil to ice up. This is the most common cause of reduced performance in systems that are otherwise mechanically sound.
We also advise on filter cleaning frequency — for most domestic installations every 6-8 weeks during periods of regular use. For commercial premises in dusty environments, more frequent cleaning is needed.
Evaporator Coil Clean (Indoor Unit)
The evaporator coil is the heat exchange surface inside the indoor unit. Over time it accumulates a coating of dust, mould and biological matter that reduces heat transfer efficiency and can become a source of unpleasant odours. We clean the coil using a specialist coil cleaning agent that breaks down biological contamination without damaging the aluminium fins or copper tubing.
A clean evaporator coil delivers noticeably better cooling performance and eliminates the musty smell that some air conditioning systems develop — typically caused by mould growth on a contaminated coil.
Condenser Coil Clean (Outdoor Unit)
The condenser coil in the outdoor unit accumulates dust, seed heads, leaf debris and other environmental contamination that impedes airflow and reduces the unit’s ability to reject heat. A heavily contaminated outdoor coil significantly reduces system efficiency and can cause the compressor to operate at elevated pressure and temperature — shortening its working life.
We clean the outdoor coil using a low-pressure water rinse and coil cleaning solution. This is particularly important for outdoor units in dusty locations (near agricultural land or building sites) or in environments with high pollen levels.
Condensate Drain Check and Clear
The indoor unit produces condensation as it cools air — this water drains away through the condensate drain pipe. If this drain becomes blocked (typically by algae or debris), water backs up and overflows from the unit — often causing water damage to ceilings and walls below. We check the condensate drain is clear and flowing freely, and treat it with a biocide tablet to prevent algae growth.
Refrigerant Pressure Check
We measure the operating pressures of the refrigerant circuit to confirm they are within the manufacturer’s specified range. Pressures outside the normal range indicate either a refrigerant leak (low pressure) or a restriction in the circuit (high pressure). Identifying low refrigerant level early — before the system stops cooling entirely — allows us to find and fix the leak before it becomes a major issue.
For commercial systems containing more than 3kg of refrigerant, this check is a legal F-Gas requirement. We record the refrigerant charge and any top-ups on the F-Gas logbook for the system.
Electrical Connection Check
We check all electrical connections at the indoor unit, outdoor unit and the isolation switch for signs of corrosion, loose connections or overheating. Loose electrical connections are a fire risk and can cause erratic system behaviour. We tighten and clean any connections found to be deteriorating.
Operational Test
We run the system in both cooling and heating modes and measure the temperature differential across the indoor unit (the difference between air temperature in and out). This confirms the system is delivering its rated performance. We also test all control functions — timer, sleep mode, self-cleaning function where fitted.
Written Report
Following the service we provide a written report confirming all checks completed, any issues found, any remedial work carried out, and any recommendations for attention. For commercial premises this report forms part of the F-Gas compliance record.
How Often Should You Service?
For domestic systems we recommend annual servicing. For commercial systems containing more than 3kg of refrigerant, F-Gas regulations require at least annual inspection — and more than 30kg requires bi-annual inspection. High-use commercial systems (running 12+ hours per day) benefit from bi-annual servicing regardless of regulatory requirements.
Cost
Our standard domestic service costs £95-150 for a single split system. A multi-split system (one outdoor unit, two or more indoor units) costs £130-200. Commercial systems are quoted individually based on the number and type of units. We offer annual maintenance contracts for both domestic and commercial clients at a reduced annual rate compared to individual service visits.
Call 07833 053749 or book a service online. We cover East Grinstead, Surrey, Sussex and South London.