Aircon Water Leak After Chemical Wash

Case Details

What We Checked

• Cooling output normal and airflow stable — no signs of refrigerant loss.
• Condensate forming on the coil and reaching the drain tray as expected.
• Drain hose connection at the tray not fully seated — visible gap at the joint.
• Water spilling forward at the unseated joint instead of flowing into the hose.

The Diagnosis

The chemical wash itself was done properly — the coil was clean and cooling was normal afterward. The problem occurred during reassembly. The drain hose connects to the condensate tray through a push-fit joint that needs to click fully into place. If the hose is not pushed in far enough, a small gap remains at the joint. Condensate collects in the tray as expected, but instead of flowing into the hose, it spills forward through the gap. Because the gap sits near the front edge of the tray, the water drips from the front panel rather than draining through the outlet at the rear. The leak appeared the next morning because overnight condensation filled the tray to the spill point.

What Fixed It

We reseated the drain hose into the tray connection until the push-fit joint clicked fully into place. Before closing the panel, we ran a water-pour test — pouring water directly into the drain tray and watching it flow cleanly through the hose and out the exterior drain outlet. This confirmed there were no secondary blockages or kinks in the hose downstream. We explained to the client that a cracked coil would show as refrigerant loss and declining cooling, neither of which was present. No parts were needed and no further work was required.

The front-panel dripping stopped completely. Cooling continued as normal, and the coil was confirmed intact.

Why This Happens

Post-wash dripping — coil damage vs reassembly gap.

• A cracked coil causes refrigerant loss and cooling decline alongside the dripping. If cooling stays normal and the unit still reaches setpoint, the coil is almost certainly intact — the drain path is the more likely cause, especially when dripping starts right after a service visit.
• Chemical wash requires removing and reseating the drain tray and hose. The push-fit joint needs to click fully into place. A gap of even a few millimetres allows condensate to spill forward instead of entering the drain pipe, and the drip often appears from the front panel edge.
• A simple water-pour test through the drain path after reassembly catches these gaps before the technician leaves. Ask your technician to run this test in front of you after any chemical wash — it takes thirty seconds and prevents callbacks.
• If dripping starts the morning after a wash where no water-pour test was done, the reassembly is the first thing to check. The timing alone — no leak before, leak immediately after — strongly points to something disturbed during the service rather than a coincidental coil failure.