The Air Conditioning Installation Process, Step by Step

Step 1: Your enquiry and initial call

You start by telling us what you want cooled or heated, where the property is, and any constraints you already know about. That might be a listed facade, a leasehold flat, a shop that cannot close, or a simple bedroom that overheats. The more detail you give at this stage, the easier it is to match you with a contractor who actually does that kind of work.

We are a quote-matching service. We do not survey or install the system ourselves. After your enquiry we introduce you to a vetted contractor in your area. That contractor should be F-Gas certified, because refrigerant handling is legally restricted to F-Gas certified engineers. Many of the contractors we match you with are also REFCOM-registered.

The first conversation is usually a short call or message exchange, not a sales pitch in your hallway. Expect questions about room sizes, how you use the space, electrics, and where an outdoor unit could sit. If you already have photos or a floor plan, send them. They will not replace an on-site survey, but they stop the contractor guessing before they arrive.

If you are ready to start, request a quote with your postcode and the rooms you have in mind. If you want the technical picture first, see what an air conditioning installation involves before you book anything.

Step 2: The on-site survey

A quote that is worth signing is based on a survey, not a photo and a guess. The contractor visits so they can measure rooms, check the electrical supply, choose indoor and outdoor positions, and plan the pipe route through your walls. Until that happens, any figure you see online is a guide, not your price.

On the day they will look at wall construction, access for drilling, condensate drainage, and whether the outdoor unit has enough airflow. They should also flag anything that might need extra consent, such as a conservation area or a shared wall in a block of flats. They cannot give you a definitive yes or no on planning for your specific property. Confirm that with your local planning authority.

You do not have to know the jargon. You do have to be honest about how you use the rooms, whether you want heating as well as cooling, and any neighbours or lease terms that might affect the outdoor unit. A thorough survey is the cheapest way to avoid a surprise on installation day.

If you want the survey itself explained in more detail, including what you should ask while they are there, read what happens during an air conditioning survey.

Step 3: The fixed-price quote

After the survey you should receive a written quote that itemises the equipment, installation labour, electrics, brackets or a base, pipework and trunking, and commissioning. Read the exclusions as carefully as the total. If making-good, decorating, a condensate pump, or a consumer-unit upgrade is not listed, assume it is not included until you ask.

Treat the quote as fixed for the scope that was surveyed, not as a promise that nothing else could ever arise. If the contractor opens a wall and finds something the survey could not see, they should stop and agree any extra work with you before carrying on. That is still subject to survey, not a blank cheque.

Do not approve a price given only over the phone. Ask for the manufacturer and model, the warranty terms, and who registers the equipment. If two quotes look very different, the usual reason is a different pipe route, a different outdoor position, or a different capacity, not a secret bargain.

When you are happy with the scope, you approve it and an installation date is booked. Until you approve it, nothing should be ordered in your name and no deposit should be treated as a reason to skip the paperwork.

Step 4: Installation day

On the day the contractor will protect floors, mark fixing points, mount the indoor unit, drill through to the outside, fit the outdoor unit, and run the refrigerant pipework, interconnecting cable and condensate drain. Refrigerant pipe connections and charging are not DIY work. They must be done by F-Gas certified engineers.

How long the visit lasts depends on the system and the building. MyJobQuote's 2026 cost guide, last updated 15 July 2026, says most air conditioning jobs take between 4 and 7 hours, and that a wall-mounted split is often done in half a day if the pipe run is straightforward. Checkatrade's 2026 advice on install duration puts a standard system at around 4 to 8 hours, and a split system at around 6 to 8 hours. Those ranges differ, and neither is a promise for your house. A long pipe run, solid walls or awkward access can stretch the same job into a second visit.

You should have cleared access to the indoor wall, the outdoor position, and the route between them. You do not need to empty the whole house. You do need to move furniture that sits where they will drill or stand. If you live in London, parking and access for tools can take as long as the drilling, so agree that before the morning starts.

For a room-by-room picture of noise, dust and whether you can work from home, read what to expect on installation day.

Step 5: Commissioning, handover and paperwork

Fitting the boxes on the wall is not the end of the job. The contractor has to pressure-test the pipework, evacuate moisture from the circuit, open or charge the refrigerant, and run the system in cooling and, if it is a heat pump, in heating. Only then can they show you that it actually does what the quote described.

Handover should include a walkthrough of the controller, night setback, filter access and what to do if the indoor unit drips. Ask them to show you the outdoor isolator and the indoor isolation points. If a fault appears in the first days, you will want to know which switch to use without guessing.

Commissioning is also when records are completed. F-Gas work has to be documented. You should leave that visit with more than a verbal "it's all working." If anything is outstanding, get it in writing with a return date, rather than hoping it will be picked up later.

What you receive at the end of the air conditioning installation process

Ask for a clear pack before the contractor leaves, not a promise that documents will follow. At minimum you should have the model and serial numbers, the commissioning record, F-Gas documentation for the refrigerant work, and instructions for the indoor controller. If the electrical work included a new circuit, you should also receive the appropriate electrical certification.

Manufacturer warranty only starts when the unit is registered. Confirm who is registering it, and keep a copy of the confirmation. A contractor workmanship guarantee is separate from the manufacturer's parts warranty. Ask how long the workmanship cover runs and what it actually includes. Do not treat either document as a guarantee of a particular energy bill or a particular room temperature on the hottest day of the year.

Keep the pack with your home file. You will need it for servicing, for any future repair, and if you sell the property. If a document is missing on the day, say so before they drive away.

The process can be done in stages if you want one room now and others later. The outdoor unit and pipe routes still need to be planned as a whole, which is why the survey comes first. When you want a date in the diary, request a quote and we will match you with a vetted contractor.