Pictured: the blower wheel of a wall unit, lifted out on one of our jobs. It sits behind the louvres, and what the louvres do is steer the air this wheel pushes out. When that steering stops working, the room stops cooling evenly even though the unit itself is running fine.
The aircon is on. The fan is going, the air is cold. But the flap at the bottom of the unit will not open, or it opens and will not swing, or it hangs at a strange angle, or it rattles. Someone in the house has been pressing the swing button for a week and nothing moves.
It looks like a small thing, and often it is. But it is also the kind of fault people either ignore for months or jump to the wrong conclusion about, so here is how we would sort it out in order, what you can safely check yourself, and what to tell us so the first visit is the useful one.
First, say exactly what you are seeing
"The flap is spoilt" covers at least five different situations, and they do not point to the same cause. Stand in front of the unit and work out which one you have.
- The flap stays shut when the unit runs. The fan is blowing, but the air is not coming out of the front properly.
- The flap opens but will not swing. It sits at one angle no matter what the remote says.
- It swings, but it will not hold a position. It drifts back, or stops short of where you set it.
- One end has dropped or the flap hangs crooked, or it feels loose to look at.
- It moves, but it clicks, grinds or rattles while it does.
Write down which one it is, and when it started. Both facts matter more than any guess about the part.
The five-minute checks you can do yourself
None of these involve opening anything.
1. Rule out the remote. New batteries first. Then press the swing button while pointing the remote at the unit from close range and watch for the unit's response, whether that is a beep or a light. Many remotes have a separate button for fixed position and for swing, so check you are not in a fixed-position setting. If the unit does not respond to the remote at all, you are not looking at a flap problem. Our post on what to check when the aircon remote is not working goes through that route properly.
2. Look at the flap with a torch. Switch the unit off at the remote, wait for the flap to close if it is going to, and shine a torch along the flap and the slot behind it. You are looking for a film of dirt, dark dots, anything stuck in the gap, or a flap that has come off one of its small pivots. A sticky grey film on the flap and the grille is common, and it is the same dirt we describe in black specks from an aircon vent. Insects and nest material can also lodge there, which is covered in ants, geckos and birds in your aircon.
3. Try a power reset, once. Switch the unit off at the remote, wait for the flap to settle, switch the unit off at its isolator or breaker for about a minute, then switch it back on and try the swing again. Some stuck behaviour clears after a power cycle. If it does, do not treat the problem as solved. A flap that needs a reset to move is telling you the motor, the board or the dirt around it is on its way out, and it will come back.
4. Note whether it began right after something. A wash or service. An installation. A thunderstorm or a power trip. The unit being moved. Tell us that first when you message, because it changes what we look for. If it began right after a visit, say so plainly. Check the full travel of the flap on the day of any job, which is why our post on what is normal after an overhaul and what goes back lists it.
What not to do
Do not force the flap by hand while the unit is powered. On many models the flap is turned by a small motor and a set of plastic gears, and pushing it against that drive is how a stuck flap becomes a stripped one. Some models are built so the flap can be moved by hand, many are not, and the manual for your model says which. If you do not have the manual, assume it is not meant to be forced.
Do not spray oil or lubricant into the slot. It collects dust, turns into a sticky film, and ends up on the coil and in the air stream. It is a quick way to turn a clean mechanical fault into a dirty one.
Do not open the front panel and start pulling at things. A unit switched off at the remote is still live. If you want to wipe the flap, do it with the unit off, the flap closed, and only on the outside surface. A damp cloth tidies what you can see. It does not fix the mechanism.
Do not keep running a unit that is blowing into a closed flap. If the flap will not open and the fan is running, the air has nowhere to go. Switch it off at the remote and get it looked at. If the unit is also dripping or has ice on it, stop and read what to do when the indoor unit is iced up first.
What it usually is, and what we cannot tell from here
Without seeing and hearing the unit, we cannot say which of these it is. This is the honest list of what produces each symptom.
- Dirt and film binding the flap. A flap that is slow, stiff, or hangs half-way is often carrying a layer of grime on its edge and in its pivots. This is a cleaning job, not a part.
- A flap that has popped off a pivot. It is mechanical, it is usually obvious on close inspection, and it explains a crooked or dropped flap.
- The motor or its gear. It explains a flap that does not move at all, or one that clicks or grinds while trying to.
- The control board or the signal. It explains a flap that ignores every command while the rest of the unit does what it is told. A board fault is a bigger conversation, and our post on what to ask before you approve a PCB board replacement covers the questions to ask.
A clean, quiet flap that will not move at all sits towards the last two. A noisy, slow or sticky flap sits towards the first. That is a hint, not a diagnosis, and anyone who tells you the cause from a photograph is guessing.
How serious is it, and does it need to be this week
It depends on which of the five you have.
Stuck open or at a fixed angle is a comfort problem more than a danger to the unit. The air blows where it blows, which might be straight down at your pillow. You can work around it with the unit's position and the fan speed while you book a visit. Our post on uneven cooling in one room explains what a badly aimed unit does to the rest of the space.
Stuck shut with the fan running should not be left running. Switch it off and book.
Rattling or a loose flap can wait a few days, but not months. A loose part that keeps moving tends to damage whatever it is rubbing against.
What it costs, and what we have not published
Here are the figures we publish that touch this job. Normal servicing is $55 for 1 unit, and that covers the visit, the 9-point pre-check and normal servicing. The pre-check includes a power and thermostat test, which confirms the electrical supply, the board response and the remote function, so it is the step that separates a remote or board problem from a flap problem. If you decline the recommended fix, the $55 covers our visit and diagnosis only.
If the flap is stuck because of grime, cleaning may be all it needs, and we would tell you that at the pre-check instead of selling you something bigger.
What we have not published is a price for replacing a flap, a flap motor or its gear. The one published repair figure is $80 for standard repair, which is listed for drainage and electrical work, so we do not apply it to a louvre. A control board replacement is quoted after diagnosis. For anything beyond a clean, the price is quoted before work starts. You can see everything we do publish on the price list.
What to send us on WhatsApp
- A short video, ten seconds is plenty, of the flap while the unit is on and you press swing. Sound on. Whether it clicks, grinds or is silent tells us a lot.
- Which of the five symptoms it is, in your own words.
- When it started, and whether it followed a service, an installation, a storm, a power trip or a move.
- The brand and roughly how old the unit is, and how many indoor units you have.
- What you already tried: new remote batteries, the reset, anything else.
- A photo of the flap with the unit off, taken with a torch along the slot, if you can.
With that, we can usually tell you whether it sounds like a clean, a part or a board before anyone comes out, and what the visit would cover.
The short version
- Say which of the five things the flap is doing. Each points somewhere different.
- Rule out the remote with fresh batteries and a close-range test.
- Look with a torch for dirt, debris or a flap off its pivot, with the unit off.
- Try one power reset, and treat a reset that works as a warning, not a cure.
- Do not force the flap, spray oil in it, or run the unit into a closed flap.
- Send a ten-second video with sound. It does more than a paragraph of description.
- Expect a clean or a part. The cost of a part is quoted before work starts, not guessed.
Flap not working properly? Tell us what you see
Send us the video, the brand and what happened before it started. WhatsApp us on 9107 2601 and we will tell you what a visit would cover before we come.