The short answer
Water in the room usually means the moisture the unit collects isn't draining away, often because of a blocked drain or dirty filters. Clean the filters and check the drain outlet, and call an engineer if it carries on.
On this page
When the indoor unit cools or dries the air, moisture from the room condenses on its cold coil. The water runs into a tray under the coil and away through a small drain pipe, by gravity or with a small pump, as described in where the water goes. A drip into the room means something along that path isn't working.
First, protect the room
- Switch the unit off with the remote.
- If water is running near a plug socket, wiring or the unit's cable, also switch the system off at its isolator switch or circuit breaker, as long as you can reach it without touching anything wet, and keep clear until everything has dried and been checked.
- Put a towel or bowl underneath, and move anything that could be damaged.
Checks you can safely make
Filters. Clogged filters starve the coil of air, so it can ice over in cooling mode. When the ice melts, the water can overflow the tray. Clean the filters, following how to clean the filters. If you can see ice on the coil behind them, leave cooling off until it has melted, with towels underneath. Fan-only mode helps it thaw.
The drain outlet. If you can see the end of the drain pipe from the ground outside, check it. It shouldn't be blocked by leaves, soil or insects, crushed or kinked, sitting under water in a gully or water butt, or frozen. Clear what you can see at the tip, but don't push anything up the pipe.
Your settings. On a humid day, with a very low temperature setting, a low fan speed and the louvres pointing down, droplets can form on the outside of the louvres and grille and fall. That's condensation on the surface rather than a drain fault. A slightly higher temperature, a higher fan speed and more horizontal louvres usually stop it.
A condensate pump, if there is one. It is usually a small box near the unit or hidden in the pipe covers. If it seems to have stopped, runs all the time or sounds different from usual, it may have failed. Don't open it: that's a job for an engineer.
A new installation. Drips from a unit fitted in the last few weeks can mean it isn't quite level, or the drain pipe doesn't fall steadily. Contact the installer.
Symptoms and likely causes
| What you see | Likely cause | Who deals with it |
|---|---|---|
| Drips on a humid day, weak airflow | Dirty filters, coil icing then melting | You: clean the filters |
| Drops on the louvres or grille | Cold air meeting humid room air | You: change the settings |
| Steady drip, filters clean | Blocked drain tray or pipe | Check the outlet, then an engineer |
| Water spat out with the air | Full drain tray, dirty coil or fan | Engineer |
| Drips where a pump is fitted | Pump failure or blockage | Engineer |
| Ice on the coil, filters clean | Low refrigerant, fan or sensor fault | Engineer |
| Dripping since installation | Unit not level or poor drain fall | Installer |
What needs an engineer
A blockage inside the unit, such as in the drain tray behind the casing, can only be cleared by taking part of the unit apart. Flushing the drain from inside, replacing a pump, re-levelling the unit and re-routing the pipe are all work for an engineer.
Ice on the coil that comes back once the filters are clean needs an engineer too, because it can point to a refrigerant leak or a fan fault. Ice on the pipes or outdoor unit explains the difference between normal frost and a fault.
The indoor unit makes little or no water when it's heating, so drips in heating mode also need looking at.
Don't pour bleach, drain cleaner or boiling water into the unit or the drain pipe, and don't push wire or rods up the pipe. They can damage the tray, the pipe or the pump, and a blockage inside the unit needs the casing off to clear anyway.
While you wait for the visit, leave cooling and dry mode off, and ask the engineer when you book whether the system is safe to use in any other mode.
Related guides
- Where the water goes: condensate drainageWater that condenses in the indoor unit as it cools runs through a drain hose to a suitable outlet, with a small pump where it can't fall naturally. In heating mode the outdoor unit produces water too.
- How to clean the filtersSwitch the unit off, lift the front panel and take out the mesh filters, then vacuum or rinse them in lukewarm water and let them dry fully before refitting. In regular use, this usually needs doing every few weeks.
- Ice on the pipes or outdoor unitA thin layer of frost on the outdoor unit while it heats in cold, damp weather is normal and clears when it defrosts. Ice that stays or keeps building, or that appears while cooling or on the pipes, points to a fault.
- When to call an engineerCall an engineer when simple checks don't fix a problem, and switch off straight away for burning smells, smoke, a circuit breaker that keeps tripping or signs of a refrigerant leak. Refrigerant, electrics and anything inside the casing are work for a qualified engineer.