Snag a new split before you pay the balance. Walk the trunking, ask to see the drain tested, and compare making good with the quote. Photograph crooked lids, unsealed holes, a condenser hard on a fence, and any stain. Model numbers, an F-gas certificate or commissioning sheet, warranty registration, the isolator and a filter demo belong on the same list. A unit that blows cold at 16C is not a passed install. That setting does not prove the drain, the paperwork or the finish.
Trunking, seals and the drain you watch
Snag on the day, before the balance, in daylight. Lids should seat, joints should be supported, and the colour should match what you accepted. A hole through the wall should be sleeved and sealed against rain and insects, not stuffed and forgotten. If the quote said the cable would be inside the trunking, a loose drape is a snag. Photograph trunking joints, seals and the outdoor stand. A stain that appears after the first rain can be added in writing. The quote should already name making good, a drain test and the handover documents, so there is something to snag against.
Making good means the decoration and the holes you agreed, not a miracle plaster job that was never priced. Read the line. If they excluded paint, your snag is an untidy chase, not the colour match. If they included it, a return visit stays on them. Photograph in daylight. Water from cooling has to leave by the route on the quote: gravity to a waste, or a pump with a stated overflow plan. A bucket is not a finish. Ask them to run it and watch the far end. If they will not test the drain, write that they refused, and do not treat the job as finished. A later puddle is harder to argue if you never asked. Photos of the hose end still help. A pump you did not know about is a snag because an empty house will not hear it fail.
Papers, a normal setpoint and the outdoor move
The outdoor unit needs its clearances, anti-vibration mounts if they were specified, and a level stand. In England, the position should still meet the Planning Portal conditions you relied on. A last-minute move onto a boundary is a snag even if the pipe run got shorter. Someone with authority should have agreed that move on the day.
No model numbers, no commissioning sheet, no warranty registration and no isolator shown are incomplete work. F-gas certification sits with the company that handled the refrigerant. Put missing documents in writing with a date. The first service is a later event, often the end of the first cooling season, unless the warranty says otherwise. Do not let a promise of a service replace today's papers. Run the unit at a normal setpoint with doors shut and windows closed, and use fan speed if the throw feels wrong. A demonstration at 16C only shows it can blow cold air. It is not a passed install. Leave a normal setpoint. Ice, a rattle, or air from the wrong room are snags. Dust and packaging are the mess list, sent the same day with its own photos. If a second firm inspects only, be plain that refrigerant pipes must not be opened without agreeing who owns the system.
Core buying guides
Start with these high-intent guides, then dig into the rest of the library.
Related guides
Sources and further reading
How this guide was prepared
This guide was written by the Local AC Installers Editorial Team. We compare official guidance, legislation and established consumer information, separate general information from project-specific advice, and show publication dates and sources. We do not accept installer accreditation claims at face value.