Book the first service for the end of the first cooling season unless the warranty text says sooner. Commissioning day is not a service, and the next morning is too soon to learn anything about filters and drains in real use. A first service checks the indoor cleanliness you can see, the outdoor coil, the drain, and the way it runs at a normal setpoint. It is not a second install, and it is not an excuse to set 16C. Read the warranty. Some brands tie the longer cover to a logged visit.
Commissioning day is not a service
A unit commissioned properly has already been vacuumed, leak checked as part of that work, and run. Coming back tomorrow only repeats the theatre. What you learn over a summer is whether the drain keeps up, whether leaves or dust arrive, and whether the indoor was sited in a draught you now hate. Book the first service for the end of the first cooling season unless the warranty text says sooner. Ask whether that visit is included in the install price or billed later.
What the first visit checks, and what you do until then
Expect filters, a look at the coil fins, a drain clear, and a check that the outdoor unit can breathe. The engineer should run it at the setpoint you use, not at the bottom of the remote. Fan speed and throw are comfort. Capacity is still the kilowatt rating on the plate. Statutory leak-check duties depend on the refrigerant charge and the rules that apply to that system. A small domestic split is not the same paperwork as a large commercial plant. Ask the company what your machine needs. Do not buy a commercial inspection because a leaflet looked official.
Keep the filter in the direction they showed you, and clean it when the manual says if it is a user filter. Keep the outdoor unit clear of toys and, later, leaves, without bending fins. Note any puddle. If you go away, remember that many splits have no true holiday mode like a boiler. Leaving cooling on in an empty house can hide a condensate leak. Energy Saving Trust's air-to-air guidance is about how these units heat and cool, not about a service schedule. The schedule is the manufacturer's warranty plus what your installer wrote down at handover.
A week-one fault stays a call-back
If something is wrong in week one, that is a call-back: water on the floor, a unit that will not hold a normal setpoint with doors shut and windows closed, or icing. Do not relabel a fault as the first service. Faults belong to the installer while the install warranty is young.
Frequently asked questions
Should the installer come back the day after fitting?
Only for a fault. A planned first service is usually after the unit has worked through a cooling season, unless your warranty states another interval.
Does a new unit need a regas at the first service?
No. A sealed system commissioned properly does not need refrigerant added as a routine. Adding gas without finding a leak is the wrong job. Ask questions if that is what you are sold.
Can I skip the service if I clean the filters?
Filters are the part you can see. Drains, electrics and the outdoor coil still deserve the visit your warranty expects. Read that wording before you decide to skip a year.
What should the service visit know beforehand?
The indoor and outdoor model numbers, the install date, and whether a pump is fitted. Say if leaves, a storm or a drip prompted the call, so they bring that job rather than a generic clean.
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.