Who is allowed to service your air conditioning

The unit database on this site holds eleven machines. Eight of them plug into a socket. Three have an outdoor unit bolted to a wall with pipework running to it.

That difference is usually presented as a question of price and disruption. It is also the line at which the law changes, and almost nothing on a retail listing tells you so.

The eight that plug in

A portable air conditioner is hermetically sealed. It leaves the factory charged with refrigerant, the circuit is closed, and nothing in normal use goes anywhere near it. You buy it, you plug it in, you empty the condensate.

There is no certification involved because there is nothing for a certificate to cover. The only refrigerant obligation that ever reaches a household with a portable unit is at the end of its life, when the gas has to be recovered rather than crushed with the rest of the machine. That is a disposal question, and it is why these do not belong in a skip.

The three that do not

Anything with an outdoor unit has a refrigerant circuit running between two boxes, and installing it means opening that circuit and charging it.

Here the rule most people find is the company one, which says a company must be certified to service stationary equipment operated by others, and which carries an exemption: a company servicing only its own equipment does not need certification.

Read quickly, that sounds like a homeowner has a free hand on their own wall. It is not what it says. Company certification is one layer. Underneath it sits the personal qualification to handle F gas, and that applies to the individual doing the work regardless of who owns the machine. Opening, charging or recovering a refrigerant circuit without it is against the law in your own house exactly as it is in somebody else’s.

So the practical position for a household is simple, even though the regulation is not: if it has an outdoor unit, somebody qualified fits it.

The annual service is not a legal requirement

This is the part that gets sold hardest and is least often true.

The duty to check equipment for leaks starts at 5 tonnes of carbon dioxide equivalent. Below that there is no leak checking obligation at all, and a single domestic split system is not close to the threshold. The frequencies above it climb in steps: yearly from 5 tonnes, every six months from 50, every three months from 500.

Those are commercial numbers. A supermarket chiller pack or an office system falls into them. One bedroom split does not.

None of which means a service is pointless, only that it is a maintenance decision you are making on the merits rather than a rule you are obeying. Anybody selling you an annual contract on the basis that the law requires it is wrong about a household unit.

What a service actually consists of

Strip out the parts you could do yourself and a genuine service on a domestic split comes down to a short list: check the charge and look for evidence of leakage, clean the indoor and outdoor coils properly rather than superficially, clear and test the condensate drain, and check the electrical connections and the fan.

Only the first of those requires the certificate. The filters, the grille and keeping the outdoor unit clear of leaves are yours, they are the jobs that most affect how the machine runs day to day, and they cost nothing.

What it costs, and why there is no number here

The honest answer is that nobody publishes one worth quoting. Servicing prices turn on how many indoor units there are, whether the outdoor unit can be reached without access equipment, and the region, and a national average applied to your job would be a guess wearing a decimal point.

What can be said is the shape of it. Only the refrigerant work needs the certificate. The filters, the grille and keeping the outdoor unit clear are yours for nothing. So a quote is mostly labour and travel, and the question to ask an installer is not “how much” but “what are you actually doing for that, and which parts of it could I do myself”.

An annual contract is a commercial offer, not a legal obligation. That is worth repeating because it is sold as though it were the other way round.

Where the money actually goes

A dirty filter makes the machine work harder for the same cooling, which shows up on the bill rather than in a fault. This site will not put a percentage on that, because the figure varies with the machine and the filter and nobody publishes one that would survive being applied to yours.

What it can tell you is the size of the thing you are protecting. Put your unit into the running cost calculator and you get what it costs to run over a summer. A maintenance decision is worth making against that number rather than against the price of the service.

Before somebody works on your system

Ask for the company registration number, then look it up on the register of the body that issued it. Refcom Certification, F-Gas Register and Bureau Veritas are the approved bodies for refrigeration and air conditioning. Certification is held at company level and has to be renewed every three years, so a certificate on a van does not tell you it is current.

The individual attending also holds a personal qualification, which is a separate document from the company one. On a domestic job it is reasonable to ask to see both, and a competent firm will not mind.

The rules referred to here are the Great Britain F gas regime, and the detail is set out in the government guidance on company certification and on checking equipment for leaks.