Air Conditioning Installation Day: What to Expect

Before they arrive: preparing for air conditioning installation day

The useful prep is access, not a deep clean. Clear the indoor wall, the floor beneath it, and the route to the outdoor position. Take pictures and shelves off the working wall. Move sofas just far enough that a person can stand and drill. Put pets in another room.

Agree parking and where the outdoor unit will sit before the morning starts. If the quote assumed a side-return and you have since filled that alley with bins, say so the day before. Changing the outdoor position on the morning can mean a different pipe route and a different finish.

You should already have approved a written quote after a survey. Installation day is not the moment to redesign the system. If you are still unsure about the process that led here, see what an air conditioning installation involves and pause until the scope is clear.

Have a kettle, a working indoor light, and a way to reach the consumer unit. Small things save more time than most people expect. If you are a homeowner arranging a domestic install, it also helps to tell neighbours that there will be drilling, especially in a terrace.

What gets drilled, cut and routed

The indoor unit hangs on a backplate. The contractor drills a hole through the wall for the refrigerant pipes, the interconnecting cable and the condensate drain. Outside, they fix a wall bracket or set the condenser on a base, then connect the pipework. Trunking may cover the pipes on an outside wall, or the pipes may run internally if that was quoted.

Core drilling is noisy for a short period. Cutting trunking and chasing, if chasing was agreed, takes longer and creates more dust. Solid brick and concrete take more time than a timber frame. MyJobQuote's 2026 guide flags wall type and pipe run length as two of the main reasons labour stretches.

Refrigerant connections are not a DIY step. Handling refrigerant is legally restricted to F-Gas certified engineers. Our vetted contractors are F-Gas certified for that work. If you see someone offering to "just run the pipes" and leave the gas for later without a qualified person, that is not a complete installation.

You will see tools, a vacuum pump at commissioning, and cable from the indoor unit to an isolator. That is normal. What should not happen is an open hole left overnight without a temporary seal if they have to return.

Mess, dust and how it is managed

There will be dust. Core drilling through masonry produces it, and no honest contractor will tell you otherwise. What you should see is dust sheets, floor protection, and a vacuum used around the hole. Ask them to show you how they will contain the indoor side before they start the drill.

External work can leave brick dust on a path or patio. That should be swept before they leave. Garden plants next to the outdoor position may need moving by you in advance. The contractor is there to fit a system, not to landscape.

Making-good of plaster and paint is only included if the quote says so. MyJobQuote's 2026 extra-costs table puts a plaster patch at around £100 and decorating at around £400 a room. Those are directory averages, not your bill, and they apply if you need a separate decorator after a chased route. Surface trunking avoids most of that mess, at the cost of a visible cover.

If the indoor unit is in a room you work in, expect the noisy part to be the drilling and the chasing, not the whole day. Commissioning is mostly waiting on gauges and listening to the indoor fan.

Do you need to be home the whole time?

Someone who can make decisions should be there at the start, when positions are marked, and at the end, for handover. In between, you do not always need to stand over the work. You do need to remain contactable. If they uncover a hidden lintel or a drain that cannot fall with gravity, they should stop and speak to you rather than invent a new route.

You can usually stay in the house. Other rooms can be used if you can keep children and pets away from tools and open doors. For a single split in one bedroom, many people work in another room for most of the visit.

If nobody can be present, you can leave keys with a trusted person who knows the agreed positions. That person must be allowed to pause the job if the contractor wants to change the outdoor location. A change of position is a change of scope.

Power, water and disruption

The contractor will need power for tools. A full house power cut is not a normal part of fitting a single split. They may isolate a circuit while they add a fused spur. If your quote includes consumer-unit work, ask whether other circuits will be off and for how long. That duration is subject to the electrician's findings, not a promise made on this page.

Water is relevant for condensate, not for a wet trade. The indoor unit will produce water when it cools. That water has to reach a drain, an outside drip, or a pumped outlet. They should not leave a pipe dripping into a neighbour's path. If gravity will not work, a pump should already have been on the quote.

Disruption is mostly noise, brief outdoor time on a ladder or scaffold, and furniture being out of place. It is not a renovation. If the job is in Leeds and the outdoor unit faces a shared yard, agree working hours with neighbours before the drill starts.

When you want the visit booked, request a quote so a vetted contractor can survey first and then give you a day that matches the property.

The handover walkthrough

Before they leave, the system should have been vacuumed, charged or opened, and run. Ask them to show cooling, and heating if the unit is reversible. Ask where the filters are, how often to clean them, and what the error codes on the controller mean. Ask where the outdoor isolator is.

Collect the paperwork on the day: model and serial numbers, commissioning records, F-Gas documentation, and electrical certification if a new circuit was installed. Confirm who registers the manufacturer warranty. A missing document is easier to fix while the van is still outside.

If something is unfinished, get the remaining items and the return date in writing. Do not accept "we'll pop back" as the whole plan.

Outdoor position is often the thing people second-guess once they hear the fan. If that worry is still open, read where the outdoor unit should go before you lock the date, not after the brackets are on the wall.