You switch on your air conditioner on a hot summer’s day; it runs perfectly for a few hours, but suddenly you notice drops of water running down the wall from the indoor unit. This is a common problem that causes concern for any home or office owner. The first reaction is usually to think that the unit has suffered a serious fault.
The truth is that A leak from the indoor unit of an air-conditioning system does not always indicate a fault with the compressor or the electronics. In most cases, the problem is blocked drainage, impaired air flow or incorrect installation — issues that can easily be rectified if addressed in good time.
How does condensation form in an air conditioner?
Every modern inverter air conditioner It absorbs moisture and forms condensation in cooling mode. When warm, humid indoor air passes through the cold evaporator (the internal coil), the moisture it contains condenses. This water is collected in the condensate tray beneath the coil and is drained out of the room via a drain pipe.
- If you notice water dripping from the external drainpipe: This is a sign that the drainage system is working perfectly.
- If water starts to drip inside the room: The condensate drainage is blocked or obstructed.
Main causes of leaks from the indoor unit
1. A blocked drainpipe or condensation tray
This is the number one cause of water leaks indoors. Over time, dust, fine airborne particles, mould and even small insects can build up and block the drain hose. The water stops draining out, the tray overflows and begins to spill over the plastic casing.
Quick check: If the indoor unit is dripping but hardly any water is coming out of the external drain pipe, the problem is most likely a blocked drain.
2. Clogged air filters
Many users underestimate the importance of regularly cleaning the filters. When they are clogged with dust, the airflow through the evaporator is drastically reduced. This causes the evaporator coil to cool excessively, leading to ice forming on it. When the air conditioner switches off or enters standby mode, the ice melts rapidly, producing a huge amount of water which overflows the drip tray.
3. Incorrect or unprofessional installation
Even the highest-grade air-conditioning equipment will not function properly without precise installation. If the indoor unit does not have the required minimum slope or the drain pipe is kinked, the water cannot drain by gravity.
4. Extreme heat and high humidity
In summer, when the humidity in Bulgaria is high, the air conditioner’s moisture absorption increases several-fold. On such days, the system produces record amounts of condensate, and even the slightest partial blockage in the drain can lead to overflow.
Risks of ignoring a leak
Persistent water dripping inside a building is not just an aesthetic problem. It can lead to:
- Damage to plasterwork, suspended ceilings, laminate flooring and furniture.
- There is a risk of a short circuit if water gets into the electrical module or the socket.
- The growth of mould and harmful microorganisms that threaten air quality.
How can you prevent leaks?
- Clean the filters every 2–3 weeks: Rinse them under lukewarm water.
- Have an annual check-up: Before the summer season, have a specialist clean and pressure-wash your drainage system.
- Invest in high-quality equipment: Crystal are equipped with optimised condensate drainage systems and self-cleaning functions.
Are you having a problem with your air conditioning, or are you looking to buy a new one?
Don’t take unnecessary risks with home improvements. The team of Crystal is at your disposal for advice, help with choosing new air-conditioning equipment and comprehensive after-sales support.
👉 Please get in touch with our specialists via the contact page or call our national helplines for a quick diagnosis!