Air Conditioning Repair

Refrigerant, and the part most people get told wrong

This is worth setting out properly because there is a lot of nonsense about it.

You cannot legally top up your own system, and it is not close. There are three separate legal bars, not one.

• You cannot buy the gas. F gases may only be sold to and bought by undertakings holding the relevant certification, or employing certified people.
• You cannot do the work. Installation, servicing, maintenance, repair and decommissioning of equipment containing F gas all require certification. Working on it without the qualification is against the law.
• Topping up instead of repairing is itself non-compliant. Where a leak is detected the operator must have the equipment repaired without undue delay. Refilling a leaking system and walking away is not a lawful repair.

The company doing the work needs certification too, not just the individual engineer.

Britain and Europe now run different F-Gas rules

Worth knowing if you are reading advice online. Great Britain still operates under the assimilated version of Regulation 517/2014. The EU repealed that and replaced it with Regulation 2024/573, which now applies in Northern Ireland under the Windsor Framework but not in England, Scotland or Wales.

So European guidance, and a fair amount of UK content written from it, no longer describes the rules that apply to your system in Hertfordshire.

Leak checks: your system probably is not caught, but that is not the whole story

Statutory leak checking is based on the refrigerant charge expressed in tonnes of CO2 equivalent, not on kilograms. The intervals are twelve months at 5 tonnes or more, six months at 50 tonnes or more, and three months at 500 tonnes or more.

A typical domestic split carrying around a kilogram of R32 works out at roughly 0.68 tonnes CO2 equivalent, and the same charge of R410A at around 2.1 tonnes. Both sit well below the 5 tonne threshold, so there is no statutory periodic leak check on a normal home installation. That is our own calculation from the published global warming potentials, and we are labelling it as such.

Light commercial crosses the line quickly. Around 2.4kg of R410A reaches 5 tonnes and brings annual checks with it. A VRF system will usually pass 50 tonnes and need checking every six months.

The distinction that matters: the leak check duty depends on charge size. The certification duty does not. A small domestic split is caught by the certification requirement exactly as a large chiller is.

When repair stops being sensible

Two regulatory changes drive this more than the age of the box.

New single split systems containing less than 3kg of refrigerant can no longer be placed on the GB market where the F gas has a global warming potential above 750. R410A is 2,088, so it is out for new single splits. R32 is 675 and is in. Larger splits, chillers and heat pumps are exempt from that particular ban.

Refilling with high GWP gas is restricted. Virgin F gas above 2,500 GWP, which catches R404A at 3,922, cannot be used to refill systems holding 40 tonnes CO2 equivalent or more. Reclaimed and recycled gas is permitted only until 2030.

Practically: an R410A system is still perfectly legal to own, run and repair. But parts and gas availability tighten over time, and on an older unit with a major component failure the sums change. We will lay them out rather than pushing you either way.

What we do on a repair visit

Read the fault code and the operating pressures rather than guessing. Check airflow, filters and both coils before touching the refrigerant circuit. Electrical checks on capacitors, contactors and the fan motors. Leak detection where the pressures point that way, so the leak gets found and fixed rather than the system refilled. Condensate line and pump checked, because that is what most of the water complaints turn out to be.

You get told what was wrong, what was done, and what is still worth watching.