Air conditioning servicing: how often, what it costs and what the law says

Quick answer: Have a home split system serviced once a year by an F-gas qualified engineer. Expect £70 to £120 per unit for a one-off service, or £150 to £200 for a typical annual visit. Legal F-gas leak checks start at 5 tonnes of CO2 equivalent, which is 7.4 kg of R32, so a typical single-room home split sits well below it.

This guide covers fixed air conditioning in homes and businesses, not car air conditioning. Last checked 10 October 2026.

What a service should include

A service is not a wipe of the filters. The best published checklist we found is in Toshiba's 2025 UK warranty guidelines, which describe the aim as keeping original performance, spotting failing parts early, and meeting the F-gas rules. Their suggested procedure includes:

• cleaning the indoor filters, heat exchanger and fan, with airflow kept above 80% of the specified value
• cleaning the outdoor heat exchanger
• checking fan motors, electrical connections and isolators for wear or overheating
• testing the condensate pump and cleaning the drain and tray
• a refrigerant leak check in line with the F-gas regulations
• measuring and recording temperatures and checking fault code history
• leaving accurate maintenance and refrigerant records on site

An installer's published scope for a domestic split looks similar: filters, indoor coils, refrigerant pressure checks, drain inspection and a test in both cooling and heating modes. If a quote for "a service" lists fewer things than that, ask what is missing.

Three practical points. Ask whether high-level units and access equipment are included, because those are the usual extras. Ask whether diagnosis of an existing fault is part of the price. And ask for the service record in writing, since a warranty claim can depend on it.

How often to service

For homes the baseline is once a year. What manufacturers say is more specific, and for several brands it is a warranty condition rather than a suggestion.

Homebuilding adds that an annual service is usually required to keep a manufacturer warranty, and that matches Daikin and Panasonic, while LG and Toshiba point to twice a year. Check the paperwork from your installer rather than assuming. A warranty that says "subject to servicing" is only as good as your service records.

Filters are your job, and more often than you think

Daikin and Samsung UK both recommend cleaning the filter about every two weeks in use. That is the one bit of maintenance you can safely do yourself, and a dirty filter is the first thing that cuts airflow. Check your manual, because the interval varies by model and by how dusty the room is.

If you use the system for cooling only, book the professional visit in spring, before the first heatwave. If it heats too, spring or autumn both work (iHeat, citing Worcester Bosch).

The F-gas law behind servicing

Two rules decide who can service your system and when leak checks become mandatory.

Who can work on it. gov.uk says anyone installing, servicing, leak-checking or decommissioning stationary air conditioning and heat pumps needs their own qualification, even if they work for someone else. A category 1 certificate covers all activities. Category 2 covers install, maintenance and service on systems under 3 kg of F gas (6 kg if hermetically sealed). Category 4 covers leak checks that do not break into the circuit. The company must also hold F-gas certification from REFCOM, Quidos (the F-Gas Register) or Bureau Veritas, renewed every three years. Our guide to checking an installer on the F-gas register shows how to confirm both.

When leak checks are mandatory. gov.uk ties the rule to the CO2 equivalent of the charge, not to the weight alone. Multiply the charge in kilograms by the gas's global warming potential, then divide by 1,000. The user of the equipment is responsible for having it checked, and if you rent out the equipment itself, the rental agreement may put that duty on you instead.

The R32 column is our calculation from the gov.uk GWP of 675, and the R410A column is our calculation from its GWP of 2,088 (gov.uk's own table gives 2.4, 24 and 239 kg for R410A at the first three thresholds). With an automatic leak detection system fitted you can double the gap between checks. gov.uk also says there is no maximum period of time between leak checks on hermetically sealed refrigeration and air conditioning systems unless they contain F gas equivalent to 10 tonnes of CO2 or more. That is the extra row above. gov.uk does not list which air conditioners count as hermetically sealed, so ask the manufacturer or your engineer whether yours does before relying on the exemption.

Here is what that means for a house. The certified Daikin FTXM35A/RXM35A pair holds 0.95 kg of R32 (Eurovent). That is 0.64 tonnes of CO2 equivalent, nowhere near 5. A typical single-room home split is under the mandatory schedule, which is why annual servicing at home is driven by the warranty and by performance, not by this regulation. Older R410A systems cross the line much sooner: 5 tonnes is only 2.4 kg of R410A, so a larger multi-split or a small shop system on R410A can already be inside the rule. Read the charge on the nameplate and do the sum, or ask your engineer to.

If a check finds a leak, gov.uk says to repair it as soon as possible and repeat the test within a month. Systems at or above the threshold also need records kept for five years: gas type and quantity at installation, gas added, check dates and results, and recovery details. If you are the user, keep the names and certificate numbers of the companies you used. You can be given a civil penalty for missing checks or not fixing leaks. Releasing F gas on purpose and unnecessarily is against the law too, and a qualified technician must recover it at the end of the system's life.

Some older guides quote a weight threshold such as 3 kg of refrigerant. Current gov.uk guidance uses tonnes of CO2 equivalent, so use that.

Commercial and larger systems

If you run a shop, office, restaurant or other premises, three things apply on top of the leak-check table.

1. Records. For equipment at or above 5 tonnes you must keep the leak-check and gas records above for five years and show them to the Environment Agency on inspection.
2. Energy inspection. Under the energy performance regulations (England and Wales), an air conditioning system with a combined effective rated output above 12 kW must be inspected by an accredited energy assessor at intervals of no more than five years. Several smaller units under one person's control can count together. gov.uk says the fine for missing it is £300. This is separate from servicing.
3. A planned maintenance contract. Ask for one that names the leak-check frequency your charge needs, rather than a generic annual visit.

What servicing costs

Prices vary with the number of units, access and what the visit includes. These are the sourced figures we found. None are Brighton-specific.

Read those as a range for a basic visit, not a quote. Note that FireFlow charges less for each extra indoor unit, so a four-room system costs less than four separate visits. Refrigerant work, parts and repairs come on top and depend on the fault, so we do not quote a regas price. Our Brighton and Hove installer pages show service prices where an installer publishes them.

Signs your system needs attention

Do not wait for the next scheduled visit if you notice one of these. They map to items on the service checklist above, so the engineer will know where to look.

Near the sea, add the outdoor unit to your checks. Toshiba's guidelines say high levels of nitrogen oxides and sulphur dioxide commonly occur within 3 miles of coastal locations, and list coil corrosion from atmospheric pollutants as a warranty exclusion unless coil protection was bought. Brighton and Hove is a coastal city, so this applies to you. Ask the engineer to look at the outdoor coil at every visit.

Regas myths

Most search results for "air conditioning regas" are about cars. Car air conditioning is a different system with a different service routine, and we do not cover it here. For fixed systems in buildings:

• "It needs regassing every year." A sealed split system does not consume refrigerant. iHeat says it should not be treated as a consumable, and a low charge means the reason needs investigating. gov.uk requires leaks to be repaired and the repair checked within a month.
• "A top-up will fix weak cooling." Weak airflow is more often a dirty filter, a blocked coil or a drain fault. Toshiba's checklist measures airflow before it mentions refrigerant.
• "Any gas engineer can do it." gov.uk lists the accredited F-gas qualification bodies (City and Guilds, BESA and LCL Awards). Gas Safe is not among them. Ask for the F-gas certificate number, because a gas registration is a different thing.
• "A self-cleaning function replaces a service." iHeat reports that Daikin advises using automatic filter cleaning where fitted while still recommending professional attention for dirty internal parts.
• "Servicing is a legal duty for every home." It is not. The legal duties are the F-gas leak checks above the threshold, and the five-year energy inspection above 12 kW. Warranty terms are what usually make servicing compulsory in practice.

Find a service engineer

Compare servicing and repair firms with F-gas status shown as checked, claimed or not found: our Brighton and Hove installer directory. To see what running costs a dirty system hides, try the running cost estimator.