Glossary · Air conditioning
What does air conditioning servicing involve?
Air conditioning servicing is the routine maintenance of an air conditioner: cleaning filters and coils, checking the drain and electrics, and checking the refrigerant circuit for leaks. Refrigerant work must be done by an engineer with a personal F gas qualification, working for a company certified to handle F gas.
Key points
- Bosch says servicing every two to three years is standard, and annually for year-round use or high humidity.
- You can clean the filters yourself. Bosch says users can do this, and it helps keep performance up.
- GOV.UK sets leak check intervals by the amount of F gas: at least every 12 months once a system holds 5 tonnes of CO2 equivalent.
- Anyone servicing other people's units needs company certification, and each engineer needs a personal F gas qualification.
How air conditioning servicing works
A service keeps a unit cooling properly and spots small faults before they become breakdowns. Dirty filters and coils make the unit work harder and cool less. A blocked drain can let water back up into the room. A slow leak of refrigerant quietly cuts performance.
How often to do it depends on the maker and on how hard the unit works. Bosch says maintenance intervals of about two to three years are standard, and that annual servicing is recommended for year-round operation or high humidity.[4]Bosch Home Comfort, Bosch air conditioners and climate control units: key facts Always check the manual for your own unit, because other manufacturers may set different intervals.
Between visits there is one job you can do. Bosch says users can clean the filters themselves, and that doing so helps keep the system’s performance up.[4]Bosch Home Comfort, Bosch air conditioners and climate control units: key facts Follow the manual for your unit and switch it off first.
What the law adds: leak checks and certification
Air conditioning is covered by F gas law. GOV.UK says that if you use stationary air conditioning equipment you are responsible for getting it checked for F gas leaks.[1]Environment Agency and Defra (GOV.UK), Checking F gas equipment for leaks If you rent out equipment, the rental agreement may make you responsible rather than the end user.[1]Environment Agency and Defra (GOV.UK), Checking F gas equipment for leaks
How often depends on the amount of gas and its global warming potential, expressed as tonnes of carbon dioxide equivalent.[1]Environment Agency and Defra (GOV.UK), Checking F gas equipment for leaks
| Gas held (tonnes of CO2 equivalent) | Leak check frequency |
|---|---|
| 5 to less than 50 | At least once every 12 months |
| 50 to less than 500 | At least once every 6 months |
| 500 or more | Automatic leak detection is needed |
For a guide, GOV.UK says 5 tonnes is 2.4kg of R410A.[1]Environment Agency and Defra (GOV.UK), Checking F gas equipment for leaks If a check finds a leak, you must repair it as soon as possible and repeat the test within a month to confirm the repair worked.[1]Environment Agency and Defra (GOV.UK), Checking F gas equipment for leaks Not having the right checks, or not fixing leaks, is breaking the law and can bring a civil penalty.[1]Environment Agency and Defra (GOV.UK), Checking F gas equipment for leaks
Who can do the work
Two layers of qualification apply. Each engineer needs a personal certificate. A category 2 certificate allows installing, servicing and recovering refrigerant on systems with less than 3kg of F gas. A category 4 certificate allows leak checks where the refrigerant circuit is not opened.[3]Environment Agency and Defra (GOV.UK), Qualifications to work with F gas
The company also has to be certified if it services equipment owned by others. GOV.UK names Refcom Certification Ltd, F-Gas Register (Quidos) and Bureau Veritas UK as approved bodies, and certification is renewed every 3 years.[2]Environment Agency and Defra (GOV.UK), Company certification to work with F gas Ask to see both before work starts.
Example
Imran runs a small salon in Bradford with a split system. He cleans the filter himself every few weeks, as the manual allows. Once a year he books an engineer. Before the visit he asks for the company’s F gas certification and the engineer’s personal qualification card. After the visit he keeps the leak check record with his equipment file, so he can show it if asked.
What people get wrong
Many owners think servicing is optional until something stops working. For a unit that holds F gas, leak checks can be a legal duty, and the person responsible is the user of the equipment unless a rental agreement says otherwise.
The other common mistake is to hire the cheapest engineer without checking certification. GOV.UK says it is against the law to work with F gas without the correct qualifications, and it asks people to report anyone who does.[3]Environment Agency and Defra (GOV.UK), Qualifications to work with F gas
The bottom line
An air conditioning service covers the filters, coils, drain, electrics and a check of the refrigerant circuit. Bosch suggests every two to three years as standard and every year for heavy use. Leak checks run on their own legal timetable that depends on the gas charge. Use a certified company and a qualified engineer, and check the manual for your own unit.
Common questions
How often should an air conditioner be serviced?
Bosch says intervals of about two to three years are standard, and recommends annual servicing for year-round operation or high humidity. Leak check intervals under F gas law can be shorter, depending on how much gas the system holds.
Can I clean the air conditioner filter myself?
Yes. Bosch says regular filter cleaning can be done by users and helps keep the system performing. Anything that involves the refrigerant circuit must be left to a qualified engineer.
Who is legally allowed to service an air conditioner?
An engineer with a personal F gas qualification, working for a company certified by an approved body such as Refcom. GOV.UK says working without the right qualification can bring a civil penalty.
Is the owner or the tenant responsible for leak checks?
The user of the equipment is responsible for getting it checked. GOV.UK says that if you rent out equipment, the rental agreement may make you responsible instead of the end user.
Sources
We cite the original source for every figure: government, regulators, standards bodies and manufacturers' own documents. Each one shows the date we last checked it.
- Environment Agency and Defra (GOV.UK). Checking F gas equipment for leaks. Checked 11 November 2026. ↩
- Environment Agency and Defra (GOV.UK). Company certification to work with F gas. Checked 11 November 2026. ↩
- Environment Agency and Defra (GOV.UK). Qualifications to work with F gas. Checked 11 November 2026. ↩
- Bosch Home Comfort. Bosch air conditioners and climate control units: key facts. Checked 11 November 2026. ↩