Put the indoor unit above a doorway only when there is room above the casing for service, the structure over the lintel can take the bracket, and the air throws into the room rather than straight down the opening. Many UK doors sit too close to the ceiling for that. The survey should measure the gap before anyone calls it a neat spot. Pipes and condensate still have to leave by a real route. An F-gas certified company fits the pair if the gap is honest.
The strip of plaster above the architrave
Wall units need clear space above the casing so the fan coil can be lifted off the bracket and the filter can come out. Measure from the top of the architrave to the ceiling, then compare it with the unit height plus the clearance on the datasheet for the model code you are being sold. A smaller casing sometimes fits where a deep one will not. Changing the code to win the gap is fine only when the cooling duty still matches the room. A photo with a tape from the architrave to the ceiling, a wider shot of where the air would travel, and the outdoor elevation, plus any light switch or bulkhead in that gap, is what the measurement needs.
Lintel, throw and water from a door head
The door leaf and the closer need to open without hitting a casing that sits too low. In a tight hall, people catch the unit with a ladder or a wardrobe on moving day. If this doorway is also the fire escape route from an inner room, do not reduce the opening or the headroom with trunking that the survey has not thought about.
A unit over a door throws toward the room or back into the hall, depending on which face you use. Over the bedroom door, blowing into the bedroom, can work if the vane lifts the air onto the ceiling and the bed is not in the first metre of throw. Blowing out onto a landing cools the landing. It is a poor bedroom install. The outdoor unit still needs a lawful spot under Planning Portal conditions in England, and the pipe length from a central doorway to that spot has to stay inside the limit. A neat indoor position with an illegal or oversized pipe run is still the wrong job. If the reply moves the unit to a side wall, that is the survey working, not a disappointment to argue away. Ask whether that gap meets the clearance for a stated model code, what the bracket fixes into, and how condensate leaves.
Frequently asked questions
Is above the door always the tidiest place?
It looks central, and it is only tidy if the clearance, the structure and the air direction work. A unit jammed into the architrave is harder to service than one on a clear side wall.
Will the air dump on people walking through?
It will if the vane is aimed down the opening. The survey should set the throw into the occupied room and check it with the door open and shut.
Can trunking run down the door frame?
Sometimes, if it does not cut the opening you need for escape and daily use. Often the better pipe route is inside the wall or along a less busy edge. The quote should draw it.
What if there are only a few centimetres above the architrave?
A doorway with a few centimetres of plaster between the architrave and the ceiling does not have that space. Forcing the unit into the gap makes every service visit a struggle and can breach the manufacturer's clearance. If the gap is too small, choose another wall.
What might the drill meet above the door?
Above a door you often meet a lintel, a concrete padstone, or a run of cables to a landing light. None of those should be discovered with a core drill. The bracket needs solid fixing either side of that zone, or a different wall. A hollow stud over a door head is a poor anchor for a unit full of coil.
Is a pump likely when the unit sits over a central doorway?
A door head in the middle of a plan is a long way from an outside gully, so a pump is common. Condensate has to fall or be pumped. The pipe length to a lawful outdoor spot still has to stay inside the manufacturer's limit.
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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.