The short answer
An annual service is typically £80–£150 per unit, and a re-gas, if a leak develops, is £100–£300. The service keeps the system efficient and the warranty valid, while certain refrigerant work must legally be done by an F-Gas-certified engineer. Skipping servicing risks higher running costs, reduced cooling and, if a leak goes undetected, an avoidable re-gas bill.
Servicing is the running cost people forget when they budget for air conditioning. A clean, well-maintained system runs efficiently and lasts; a neglected one loses cooling, costs more to run and is more likely to fail. This page sets out the typical service and re-gas costs, what the work involves, and which parts of it the law reserves for certified engineers.
Servicing cost at a glance
- Annual service £80–£150 per unit
- Re-gas (after leak) £100–£300
- Who may handle refrigerant F-Gas-certified engineer only
- Service frequency Usually once a year
- Owner task Regular filter cleaning
What a service includes and costs
An annual service typically costs £80–£150 per unit. The engineer cleans or replaces filters, checks and cleans the coils, inspects the condensate drain, verifies the electrical connections and confirms the system is operating correctly and within its refrigerant charge. The aim is to keep the unit efficient, catch small problems early and maintain manufacturer warranty conditions, which often require documented annual servicing to remain valid. A dirty coil or clogged filter makes the unit work harder and draw more power, so the service often pays for part of itself in lower running cost.
- Clean or replace filters and check airflow.
- Inspect and clean coils, drain and electrical connections.
- Confirm correct operation and refrigerant charge.
- Record the service for warranty purposes.
Re-gas and leak repair
If a unit loses refrigerant through a leak, it cools poorly and works harder, which shows up as weaker cooling and higher bills. A re-gas typically costs £100–£300, but a re-gas without finding and fixing the leak is only a temporary fix — and under GB F-gas law, deliberately venting refrigerant or knowingly topping up a leaking system is not acceptable practice. The correct route is leak detection, repair, then recharge by a certified engineer. A system that needs frequent re-gassing has an unresolved leak, not a normal maintenance need. See re-gas explained and air con not cooling.
| Task | Typical cost | Frequency |
|---|---|---|
| Annual service | £80–£150 per unit | Yearly |
| Re-gas after leak | £100–£300 | Only when refrigerant is low |
| Filter clean (owner) | £0 | Every few weeks in use |
Why certification matters
Under the GB F-gas regime, only an F-Gas-certified engineer working for an F-Gas-registered company may install, service, recover or recharge a system containing fluorinated refrigerant. This is not a formality: refrigerant is a regulated greenhouse gas, and improper handling is both illegal and environmentally harmful. A cheaper “service” that touches the refrigerant circuit without certification is illegal work, and it may also invalidate your warranty and insurance. Always ask to see the engineer’s F-gas certification and the company’s registration.
What you can do yourself
Owners can keep costs down between services by cleaning or rinsing the filters regularly, keeping the outdoor unit clear of leaves and debris, and reporting any drop in cooling early so a small fault does not become a re-gas. The Energy Saving Trust’s general principle holds: a well-maintained appliance runs more efficiently and lasts longer, which spreads its purchase cost over more years. For routine care see maintenance tips and the schedule in how often to service.
What neglect actually costs
Skipping servicing rarely saves money in the long run. A filter left to clog restricts airflow, so the unit runs longer and draws more power to reach the same temperature — a quiet, continuous tax on your electricity bill. A small refrigerant leak left unfound means weaker cooling and harder running until it becomes an avoidable £100–£300 re-gas, on top of repairing the leak. A blocked condensate drain can lead to water escaping from the indoor unit. And many manufacturer warranties require evidence of regular servicing, so a missed service can leave you paying for a repair that would otherwise have been covered. Set against an annual service of £80–£150 per unit, these are poor savings. The cheapest approach over a system’s life is steady, documented maintenance by a certified engineer, with the owner handling the filters in between.
These figures are typical 2026 market ranges for guidance, not a fixed quote. Costs vary with the unit, the fault and your location.
Budget for servicing, not just buying
Set aside £80–£150 per unit a year for a service from an F-Gas-certified engineer, and clean the filters yourself between visits.
Frequently asked questions
How much is an annual air con service?
Typically £80–£150 per unit. It covers filter and coil cleaning, drain and electrical checks, and confirmation that the system is operating correctly.
How much does a re-gas cost?
A re-gas is generally £100–£300, but it should follow leak detection and repair, not simply top up a leaking system. Only a certified engineer may do this.
Do I legally have to service air con?
Servicing is strongly recommended for efficiency and warranty, and any work on the refrigerant circuit must be done by an F-Gas-certified engineer. Filter cleaning you can do yourself.
How often should air con be serviced?
Usually once a year for a domestic system, with the owner cleaning filters every few weeks during heavy use. Commercial systems may need more frequent attention.
Sources & further reading
- gov.uk — the Fluorinated Greenhouse Gases Regulations 2015 (GB F-gas)
- REFCOM / the F-Gas Register — certified engineer and company requirements
- Energy Saving Trust — maintenance and efficiency guidance
- gov.uk — DEFRA F-gas guidance on handling refrigerant
This guide is general information, not a site-specific survey or a substitute for a quote from an F-Gas-certified installer. Installation, servicing and refrigerant handling are legally restricted to F-Gas-certified engineers.