Photograph the mess before you sweep it, the same day, and send those pictures to the installer while the crew is still local. Masonry dust, cable offcuts, packaging and boot prints on a protected floor are a finishing failure, even when the F-gas work is sound. A fair install leaves the drill zone swept, packaging taken, and making good either done or written as a return. If the quote promised protection and a clean, hold them to that line. Pay the balance only when you know what is still outstanding.
A swept drill zone before the van goes
The core hole should be sleeved and sealed, trunking wiped, and the floor under it free of grit and screws. Packaging for the indoor and outdoor units should leave with the van. Dust on a surface you cleared is a wipe. Dust ground into a sofa they asked you to leave in place is a complaint with a photo.
Some dust in a drill zone is normal during the day. A room abandoned under a grey film, with the vacuum still in the van, is not. Say so before they depart if you can. It is easier on the doorstep than by email at 9pm. Photograph before you clean, and include the trunking, the floor and any packaging. Write what the quote said about protection and making good.
Mess, snags and the papers that still matter
The installing firm should return for the mess they caused if the quote included a tidy finish. A decorator's making good is only theirs if it was listed. Citizens Advice sets out the general approach to home improvements that are not finished as agreed. Keep the paper. If they refuse a reasonable return, then you have a dispute, not a reason to open the refrigerant pipes yourself.
A puddle from an untested drain, crooked trunking, and a missing isolator label are snags. Dust is a mess. List them separately so a return visit brings the right person. An apprentice with a hoover cannot fix a drain. An engineer in a hurry may not bring boxes for the rubble. Commissioning paperwork should still be in your hand. Mess does not cancel the need for model numbers and an F-gas record. If another firm is asked to look, the scope is the mess or a commission check. Do not ask a new firm to finish the gas on a system someone else charged unless they have agreed to take that responsibility.
Frequently asked questions
Should I clean up so the house is usable tonight?
Photograph first, then make it safe. A sweep after the pictures does not weaken a polite same-day complaint. Throwing the packaging away before you photograph it does.
Can I withhold the final payment?
If the quote tied the balance to a finished, tidy install, say what is outstanding and pay for what is complete. Keep it in writing. Citizens Advice covers the general consumer approach. Do not invent a figure.
The cooling works. Does the dust still matter?
Yes. A working unit and a filthy room can both be true. Ask them back for the mess. Keep the technical snags on their own list.
Can I add a cleaner's bill without asking?
No. Do not hire a cleaner and assume you can add the bill without asking. Ask first, in writing, with the photos.
Should I blow the dust out with the unit running?
Do not run the unit as a way to blow the dust out with the windows open. Close the windows when it cools, at a normal setpoint, once the air paths are safe. 16C and an open sash only add a second problem.
Are offcuts a reason to keep pets out?
Yes. While you wait, keep children and pets off screws and offcuts. Separate that mess from a drain snag or a missing isolator label.
Core buying guides
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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.