How Often Should Air Conditioning Be Serviced? (UK)
How often to service air conditioning, what you can do yourself, what a professional service includes, and when a leak check is a legal requirement under GB F-Gas rules.
By Max Tuleberg · Founder, Vento · Last updated 25 October 2026
Founder of Vento. Worked on the tools before building the software.
Have your air conditioning serviced once a year, which is what most manufacturers recommend, and clean the filters yourself every few weeks while it's in use. A legal leak check only applies to larger systems, so most homes fall below it — but a service keeps the system efficient, quiet and within warranty.
What you can do yourself
- Clean the filters every few weeks during regular use — they usually lift out and can be vacuumed or rinsed. Follow your user manual.
- Keep the outdoor unit clear of leaves, plants and anything stacked against it.
- Watch for warning signs: water dripping from the indoor unit, ice on the pipes, new noises or smells, or the room taking longer to cool.
Never open the refrigerant circuit or top up refrigerant yourself — that work must be done by an F-Gas certified engineer.
What a professional service includes
- Filters and indoor coil cleaned, and the fan checked.
- Condensate drain and pump checked and cleared.
- Outdoor unit cleaned and checked for damage or obstructions.
- Electrical connections, controls and the remote checked.
- Operating temperatures and performance measured against normal values.
- A leak check, where the system's size makes one mandatory.
When a leak check is a legal requirement
Under GB F-Gas rules, mandatory leak checks depend on the system's refrigerant charge in tonnes of CO₂ equivalent (CO₂e) — the charge in kg multiplied by the refrigerant's global warming potential (GWP), divided by 1,000. Below 5 t CO₂e there is no mandatory check.
| Example system | Refrigerant (GWP) | CO₂e | Mandatory leak check |
|---|---|---|---|
| Single-room split, 1.5 kg | R32 (675) | 1.01 t | None |
| Older system, 3 kg | R410A (2,088) | 6.26 t | Every 12 months |
These are examples to show the sum, not your system — the charge is on the outdoor unit's rating plate. For any system, use the leak-check interval calculator or read the leak-check intervals guide.
Why servicing matters
Clogged filters and dirty coils make the system work harder, which raises running costs and shortens its life. A blocked condensate drain is the most common cause of water leaking from an indoor unit. And if your system came with an extended manufacturer warranty, regular servicing is often a condition of keeping it.
This guide is general information for UK installers, not legal or regulatory advice. Always check the current regulations and manufacturer instructions for your specific job.
Frequently asked questions
How often should air conditioning be serviced?
Most manufacturers recommend a professional service once a year, and some require it to keep an extended warranty — check your warranty terms. In between, clean or vacuum the indoor unit's filters every few weeks while it's in regular use, as your user manual describes.
Is an air conditioning leak check a legal requirement?
Only for larger systems. Under GB F-Gas rules a leak check is mandatory from 5 tonnes of CO₂ equivalent. A typical home split using R32 would need more than 7.4 kg of refrigerant to reach that, so most single-room systems have no mandatory check — but an annual service is still recommended.
What happens during an air conditioning service?
Typically: filters and indoor coil cleaned, condensate drain checked and cleared, outdoor unit cleaned and checked for obstructions, electrical connections and controls checked, and the system's operating temperatures and performance checked. Any work on the refrigerant circuit must be done by an F-Gas certified engineer.
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