Water on the floor under your indoor unit is your aircon telling you something specific — not just “it’s old.” Six things cause a leaking aircon, and only one needs more gas. Here’s how to tell which, and what a fix should cost.
Every running air conditioner produces water as a normal by-product. Cooling the air lowers its temperature below the dew point, so moisture condenses on the evaporator coil the same way water beads on a cold glass. In normal operation that condensate runs off the coil into a drain pan, down a drain pipe, and out of the building — several litres a day for a typical unit, more in Malaysia’s humidity. “Aircon leaking water” simply means that normal condensate is going somewhere it shouldn’t — onto the wall, the floor, or through the ceiling — instead of down the drain. The unit is not making more water than usual in almost every case; the water is failing to leave the way it’s supposed to.
| Symptom | Likely cause | What to check | When to call a professional |
|---|---|---|---|
| Steady drip, worse the longer the unit has run | Clogged condensate drain | Look at the outdoor drain outlet — is water actually coming out of it while the unit runs? | If no water is coming out of the outdoor drain point at all |
| Drip appears after the unit has run for hours, especially overnight | Coil icing from a dirty filter, then thawing | Open the unit and look at the filter — visibly dusty or grey means this is likely it | If a clean filter doesn’t stop the icing |
| Weaker cooling as well as dripping, sometimes with a hissing sound | Low refrigerant, coil icing | Feel the two copper pipes at the outdoor unit — both cold, or frost visible, points this way | Yes — a leak needs finding and repairing, not just topping up |
| Water drips from a specific spot on the unit’s casing, not the drain area | Cracked or misaligned drain pan | Visual inspection inside the unit cover, ideally by a technician | Yes — the pan needs replacing or re-seating |
| Sudden leak after years of no issue, no gravity drain visible | Failed condensate pump | Check whether the installation has a visible pipe running downhill outside, or a small pump box | Yes — pump repair or replacement |
| Leak from day one of a new installation | Improper installation tilt | Note that it started immediately after install, not gradually | Yes — ask the installer to re-check and re-level the unit |
Send us a photo of the job on WhatsApp — we reply with an instant quote.
💬 Get Your Instant QuoteA window unit sits in the wall itself and typically drains condensate straight outside through the back of the casing, so a leak usually means the unit is tilted the wrong way (toward the room instead of away from it) or the drain hole at the back is blocked. A split system’s indoor unit is mounted well inside the room, with the water carried away through a dedicated drain pipe run inside the wall or trunking to an outside point — which is exactly why a split-unit leak more often shows up as a clogged drain line or a failed pump rather than a simple tilt problem, since there’s a whole concealed pipe run between the unit and the outside that can block anywhere along its length.
Contain first, diagnose second. Place a container under the drip, move electronics and furniture out of the area, and if the water is anywhere near a light fitting, socket or the distribution board, switch off that circuit at the DB box until things are dry and checked. Then look at whether the unit is dripping from the front casing (points toward a pan, tilt or overflow issue) or whether the water is tracking down a wall or ceiling some distance from the unit (points toward the concealed drain pipe run, or possibly a source that isn’t the aircon at all — see below).
Do not top up the gas yourself, and be wary of anyone who suggests refrigerant as the first fix without checking anything else first. An air conditioner is a sealed system: the refrigerant circulates for the life of the unit and does not run low from normal use, so a genuine shortage always means a leak, and gas added without finding and repairing that leak buys you the same drip again in a few months. Do not ignore a recurring drip near electrical fittings — water and a light fitting or socket is a shock risk, not just a mess. And do not force anything rigid into the drain line trying to clear it — a cracked pipe from a DIY clearing attempt is a bigger job than the original clog.
If the water is showing up on a ceiling rather than dripping from the unit itself, it isn’t always your aircon — it could be the unit above yours in a stacked condo, a concealed water pipe, or slab seepage from an upstairs wet area. Our aircon leak vs pipe leak in the ceiling guide walks through how to tell those apart by where the stain sits and when it drips, which is worth reading before you assume the fault is your own unit.
A technician works through the causes above in order of likelihood and cost rather than guessing. A chemical wash — a full strip-down clean of the coil, blower and drainage tray — clears the great majority of drips caused by a blocked drain or a dirty coil, and is usually the first thing tried because it’s the cheapest fix that addresses the two most common causes at once. If cooling is also weak, they’ll check for a refrigerant leak, which means finding and repairing the leak point before re-gassing — not a bare top-up. A cracked pan, failed pump or installation-tilt problem is confirmed by opening the unit and is a parts or re-installation job rather than a cleaning job.
Because water dripping from the indoor unit is one of the standard signs a chemical wash is due, that’s usually the starting price point: RM120–RM180 for a 1.0–1.5HP wall unit, per our chemical wash guide (or RM120–RM250 across unit sizes per our broader aircon servicing cost guide). If a chemical wash doesn’t resolve it, a diagnostic visit runs RM60–RM120 and is often credited toward the repair if you proceed, per our aircon repair guide — from there, a refrigerant leak find-and-repair or a pan/pump replacement is quoted after inspection, since the part and the access involved vary by unit (all figures: market estimate 2026, indicative Klang Valley).
| Cause | Typical fix | Roughly what it costs |
|---|---|---|
| Clogged condensate drain | Chemical wash / drain flush | RM120 – RM250 |
| Dirty filter or coil icing | Filter wash, then a chemical wash if icing already occurred | RM120 – RM250 |
| Low refrigerant (a leak) | Find and repair the leak, then re-gas | Quoted after inspection |
| Cracked or misaligned drain pan | Pan replacement or re-seating | Quoted after inspection |
| Failed condensate pump | Pump repair or replacement | Quoted after inspection |
| Improper installation tilt | Re-level or re-install the unit | Quoted after inspection |
Regular servicing is the cheapest insurance against a leak. A filter wash every 3–6 months keeps airflow across the coil healthy and prevents icing, and an annual chemical wash keeps the drain line and coil clear of the slime and dust that eventually block the drain. Units that run for long hours daily, or bedrooms used by allergy-prone household members, benefit from a chemical wash closer to every 12 months rather than 18. If your unit has ever leaked before, treat it as a sign the drain line needs attention sooner rather than waiting for the next drip.
ClickBina services and repairs aircon units across Kuala Lumpur and Selangor, and we diagnose before we quote — a chemical wash where that’s genuinely the fix, a proper leak find-and-repair where refrigerant is involved, and honest parts advice where a pan or pump has failed. WhatsApp us a photo of where and when it drips, and we’ll tell you what it likely is before anyone comes out.
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