Aircon Water Leak Only When Raining

A leak that only appears during rain is rarely a standard drain fault. It usually means rainwater is entering through a wall opening, weather pressure is disrupting drainage, or water is reaching electrical points — and each scenario needs a different response.

SAFETY WARNING

Stop using the unit and contact a technician if you notice water near electrical points or wiring, breaker tripping repeatedly, burning or electrical smell, or visible sparking signs.

External Rain Ingress Through Wall or Trunking Path

Unsealed or poorly sealed wall penetrations let rainwater track along the pipe sleeve or trunking into the indoor space. The water follows gravity and often appears at the lowest point of the trunking run.

Leak appears during rain and reduces after weather clears.
Water trails follow wall opening or trunking route.
Cooling may still feel normal.

We trace the entry path from outside, seal the wall penetration or trunking gap, and confirm the indoor leak stops after the next rain event. Gas or cooling work will not fix a rain ingress path.

Drain Path Affected by Weather Pressure Pattern

Strong wind during heavy rain can create back-pressure on an exposed drain outlet, pushing condensate water back through the pipe and causing overflow at the indoor unit or along the trunking run.

Leak appears while unit runs during rain periods.
Water pattern changes with wind and rain intensity.
Drip points shift between outlet and nearby paths.

We inspect the drain outlet exposure and routing, add a wind-guard or re-route the discharge point if back-pressure is confirmed, and retest during operation. Treating this as a permanent indoor leak without weather context can mislead diagnosis.

Rainwater Near Electrical Points

Water tracking along pipes or trunking can reach the isolator switch, terminal block, or exposed wiring. This creates shock and trip risk that must be treated as a safety issue before any cooling diagnosis.

Water appears near switches, isolator, or wiring points.
Breaker trips during rain-linked leak events.
Electrical smell appears with leak pattern.

Stop using the unit until electrical safety is confirmed. We isolate ingress and verify safe power condition first. Do not continue operation when water reaches electrical points.

Not Always a Fault

Heavy rain and wind direction can temporarily change how external moisture moves around wall penetrations.

How to Tell

Leak appears only during certain rain directions.
Pattern reduces once weather clears.
No leak during dry conditions under similar cooling load.

If water reaches electrical areas, treat it as urgent regardless of weather pattern.

Help Us Diagnose Faster

Just observe safely from a distance, no disassembly required:

Leak location: wall opening / trunking path / indoor unit edge
Weather link: only in rain / rain plus unit running / also in dry weather
Water pattern: steady drip / sudden bursts / spreading along wall path
Electrical signs: none / breaker trip / water near switches or wiring

Same situation with your aircon?

Describe what’s happening. We’ll work out the likely cause and tell you the right next step.

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