Air Conditioning Leak Repair in London
Air conditioning leak repair in London starts from £120 plus VAT. F-Gas certified engineers locate refrigerant leaks, repair the joint or component, pressure test the circuit and recharge the system to the correct weighed charge.
Report a leak · 07414 254125Refrigerant leaks versus water leaks
There are two very different kinds of air conditioning leak. A water leak, dripping from the indoor unit, is almost always a blocked condensate drain, a failed condensate pump or a unit that is not level. It is unpleasant, can damage ceilings and furniture, but does not involve the refrigerant circuit.
A refrigerant leak is a loss of gas from the sealed pipework between the indoor and outdoor units. Refrigerant does not get used up, so if the level is low there is a leak somewhere. Left alone, low refrigerant causes weak cooling, frozen coils and eventually compressor damage, which is the most expensive repair on any system. We repair both types, and the engineer will confirm which one you have on the first visit.
Signs of a refrigerant leak
The most common sign is a system that runs but no longer cools or heats properly. Ice forming on the copper pipes, the outdoor service valves or the indoor coil is another strong indicator, because low pressure makes the coil run too cold. You may also hear a hissing or bubbling sound near the pipework, see oily residue at flare joints or brazed connections, or get a low-pressure fault code on the controller.
If the system was regassed in the past and has lost performance again, the original leak was probably never found. Topping up gas without repairing the leak wastes money and releases more refrigerant into the atmosphere, which the F-Gas Regulations are designed to prevent.
How we find and repair the leak
Leak detection starts with a visual inspection of flare nuts, brazed joints, service valves, coils and any pipework that runs through walls or ceiling voids. The engineer then uses an electronic refrigerant detector and bubble solution to pinpoint the exact source. Where a leak is too small to find under normal pressure, the circuit can be recovered and pressurised with oxygen-free nitrogen to make it easier to locate.
Common repairs include remaking or replacing flare joints, re-brazing a cracked connection, replacing a leaking service valve, or repairing or replacing a corroded coil. After the repair, the circuit is pressure tested with nitrogen to prove it is sealed, then evacuated with a vacuum pump to remove air and moisture. Only then is refrigerant weighed back in to the charge on the data plate.
Systems and refrigerants covered
We repair leaks on wall-mounted splits, multi-split systems, ceiling cassettes, ducted units and VRF/VRV systems in homes, offices, shops, restaurants and server rooms. Brands include Daikin, Mitsubishi Electric, Mitsubishi Heavy Industries, Toshiba, Fujitsu, Panasonic, Samsung and LG. Air conditioning commonly uses R32, R410A or R407C; refrigeration equipment uses gases such as R404A, R448A and R449A. These refrigerants are not interchangeable, and the correct gas is always taken from the unit's data plate. All work on the refrigerant circuit is carried out by F-Gas certified engineers in line with the F-Gas Regulations 2014.
Leak checks and F-Gas record keeping
Larger commercial systems above certain refrigerant charge thresholds must be leak checked at set intervals under the F-Gas Regulations, and records kept of every check, repair and refrigerant addition. After a leak is repaired, a follow-up check confirms the repair has held. If your building has several systems, a planned maintenance contract can schedule these checks and keep your records in order.
Repair or replace?
Most leaks are worth repairing, especially on systems under about ten years old. Where a coil is badly corroded, an older system uses a refrigerant that is costly to source, or leaks keep recurring in different places, replacement can be better value over time. The engineer will explain the options and we can quote for both, so you can decide with the full picture.
Air conditioning leak repair prices
Prices exclude VAT. The final price is confirmed in writing after the leak is found.
| Service | Price | Notes |
|---|---|---|
| Air conditioning leak repair | From £120 plus VAT | Depends on leak location and access |
| Refrigerant leak detection | Included in the written quote | Electronic and bubble testing |
| Air conditioning expansion valve repair | £160–£280 | Typical published repair cost |
| Air con regas after leak repair | From £120 plus VAT | Weighed charge after pressure test |
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Air conditioning leak repair frequently asked questions
How much does air conditioning leak repair cost?
Air conditioning leak repair starts from £120 plus VAT. The final price depends on where the leak is, how easy it is to reach and whether a part needs replacing. A regas after the repair starts from £120 plus VAT. You get a written price before work starts.
How do I know if my air conditioner has a refrigerant leak?
Common signs are weak cooling, ice on the pipes or indoor coil, a hissing sound, oily marks at pipe joints or a low-pressure fault code. If the system needed gas before and has lost performance again, a leak is very likely.
Can you just top up the gas instead of fixing the leak?
Topping up without repairing the leak only delays the next failure and releases more refrigerant into the atmosphere. Under the F-Gas Regulations, leaks should be repaired before the system is recharged, so we find and fix the leak first.
Why is water leaking from my indoor unit?
Water dripping from the indoor unit is normally a blocked condensate drain, a failed condensate pump or a unit that is not level. It is not a refrigerant leak. The engineer clears or repairs the drain and checks the unit is level.
How long does a leak repair take?
Simple flare joint repairs are often completed in one visit. Larger repairs take longer because the circuit must be pressure tested and evacuated before recharging. The engineer confirms the expected time once the leak has been located.