Air conditioner · Naples and Campania
Air conditioner leaking water: why it happens and what to do
While cooling, the split removes moisture from the air and sends it outside through a small tube. If that water finds the way blocked, it falls into your home. In most cases the problem is in the condensate drain and is solved without touching the gas.
From €250 + VAT about 3 hoursSingle split, back to back, up to 3 m of piping, F-gas certification included
Water and electricity do not mix: if water falls near a socket or a power strip, cut the power to the air conditioner at the fuse box before wiping up. Do not stand on unstable chairs to reach the split and do not lean off the balcony to reach the outside tube.
Recognise the problem
- Drops falling from the lower edge of the split
- A trickle of water running down the wall below the indoor unit
- A damp patch around the hole where the pipes pass through
- Outside, the condensate tube no longer drips
- Water running from the outdoor unit, especially when you use it for heating
- Gurgling or the sound of water inside the split
The most common causes
- 1
Blocked condensate tube
Mould, dust and sometimes small insects form a plug in the tube. Water fills the internal tray and overflows. This is the most frequent cause, especially at the start of the season.
- 2
Dirty filters and ice
With little airflow the coil ices over. When the ice melts, the water arrives all at once and the tray cannot handle it.
- 3
Split out of level or tube sloping the wrong way
Condensate flows down by gravity. If the unit is not level or the tube has a hump going up, the water stagnates and looks for another way out.
- 4
Condensate pump stopped
When the split is on an internal wall, there is sometimes a small pump that pushes the water to the drain. If it gets dirty or jams, the water stays inside and overflows.
- 5
Damaged pipe insulation
The gas pipes are covered with an insulating sleeve. If it is torn, condensation forms on the cold pipes and wets the wall near the hole.
What you can safely check yourself
- Switch off the split, cut the power and put a towel or a bowl underneath.
- Slide out the filters and wash them if they are dirty.
- Go to where the small tube comes out outside and check it is not crushed, kinked or ending in a pot or a full bucket.
- Look at the split from the side. If it visibly leans to one side, make a note and show it to us on the video call.
- If only the outdoor unit drips while heating, see if it happens at intervals: defrosting is normal.
Never open the boiler or the gas water heater, and always switch off the power before touching an electrical appliance. If in doubt, call us.
When you need a technician at home
- The outside tube is clear but it keeps dripping indoors
- The condensate tube runs inside the wall and cannot be reached
- The split needs to be put back level on its brackets
- The drain pump needs replacing or the pipe insulation redoing
- The coil and tray are full of dirt and mould
How much it costs
Air conditioner installation (our price)
Single split, back to back, up to 3 m of piping, F-gas certification included
from €250 + VAT
Full clean including condensate drain
indicative market price in the Naples area, per split
60-90 €
Market figures are indicative for the Naples area. You know our exact price before we start; prices apply near our base in Parete, and further away you see them in full when you choose your town.
When the water is normal
If the small tube outside drips in summer, all is well: it is condensate leaving from the right place. The problem is when the water comes down indoors, or when nothing falls outside after the split has been cooling for an hour.
The outdoor unit can also drip. This happens when you use the air conditioner for heating: now and then the outdoor motor defrosts, meaning it stops or reverses the cycle to melt ice on the fins, and the water runs underneath.
If that water, or the summer condensate, ends up on the neighbour's balcony below, it can be taken by a pipe to a drain. In a condominium it is the simplest way to avoid arguments.
How to clear the drain without causing damage
When the outside end of the tube is within reach, sometimes it is enough to suck with a vacuum cleaner, holding the tube tight in the nozzle, to remove the plug of dirt. On a video call we show you how to do it safely.
Avoid: neat bleach, caustic soda or sink-clearing products poured into the tray. They damage the plastic and the fins and leave a smell. Never pierce the tray to let the water out.
If the tube runs inside the wall, or the condensate discharges into the household stack, work is needed: the drain must be cleaned from the inside and the trap checked, the curved section that holds a little water and blocks odours.
Want to know what it is first? Show us
You show us where the water falls from, the filters and the point where the small tube exits outside. We work out whether the drain is blocked, whether the split is fitted crooked or whether ice is forming. Often we guide you to clear the tube yourself, otherwise we tell you whether a full clean is needed.
Video consultation, up to 15 minutes: €9.90 (€14.90 on Sundays), deducted from the bill if we then come to your home.
Book the consultationDIY guides
Frequently asked questions
Why is my air conditioner leaking water from the indoor unit?
Almost always because the condensate drain is blocked or because dirty filters make the coil ice over. More rarely the split is fitted at a slant. If it still drips after cleaning the filters, the tube needs clearing.
Is it normal for the outside tube to drip?
Yes, while the split is cooling it is normal, and it is actually a good sign: the drain works. You only need to check where that water ends up, so you do not wet someone else's balcony.
The outdoor unit is leaking water: is it a fault?
If it happens while heating, usually not: it is defrosting. If you see water under the outdoor motor while cooling, it is often the split's condensate tube ending right nearby. On video we tell the two apart in a few seconds.
Can I keep using it while it drips?
Better not, especially if the water lands on sockets, furniture or parquet. Switch it off, clean the filters and try clearing the drain. If it drips again after an hour of use, it needs checking.
Why does it leak even when switched off?
Usually ice melting after switch-off, or water left in the tray. But if the stain keeps growing after days of not using it, check that it is not coming from a pipe in the flat above or from damp in the wall.
You may also be interested in
Air conditioner all over Campania
We work in Naples, Posillipo, Caserta and all over the region. Near our base in Parete there is no travel cost; further away you see the full price before you confirm.
Ready when you need us.
Book your visit by choosing a day and time. For emergencies we answer 24 hours a day, across Campania.