How long do condensate pumps last?

Between 5 and 10 years in Singapore's climate. It depends on how often the pump chamber is flushed during servicing. Areas with harder water see faster scale buildup. Annual flushing can add years to the pump's life.

Is this covered under any warranty?

The condensate pump is a wear item. It's usually not covered after the first year of the unit warranty. If you have a maintenance contract that includes parts, check if it covers the pump. In this case there was no active parts contract.

How do I prevent this from happening again?

Ask your technician to flush the pump chamber with a dilute descaler at every annual service. It removes the scale before it builds up enough to seize the impeller. It adds a few minutes to the visit and avoids a pump replacement further down the line.

Concealed unit dripping traced to seized condensate pump

Aircon case in Central Area, Singapore: water leakage traced to condensate pump seized from scale and algae buildup inside the chamber after targeted diagnosis checks.

Case details

What client reported

Water had started dripping from the unit panel two days earlier. It started small but was getting worse. The customer was worried about water damage and asked if the unit was leaking refrigerant.

ProblemWater leakage

UnitMitsubishi Electric · Ceiling · 7 years old

LocationCondo · Central Area, Singapore

What we found

We opened the access panel to check the tray and drain path first.

Condensate tray was overflowing — water above the tray lip, seeping through panel joints
Drain pipe from tray to pump inlet was clear — not blocked
Pump had power but shaft would not turn — seized
Pump chamber opened — scale and algae deposits locked the impeller in place

Scale and algae had built up inside the pump chamber over seven years. The impeller got harder to turn until it seized. With the pump stopped, water built up in the tray and overflowed.

What we did

The seized pump was replaced with a matched unit. The tray was cleaned and dried. The drain pipe was flushed. The new pump was primed and tested through a full drainage cycle before the panel was closed.

Dripping stopped straight after the pump was replaced. The customer was advised to add pump chamber flushing to the annual service. It's a step some technicians skip on concealed units because it requires opening the panel.

Timeline

Day 1

Water dripping from unit panel noticed — getting worse

Day 2

Access panel opened, tray found overflowing, pump shaft would not turn

Day 2

Overflowing tray and seized pump confirmed, pump replaced and tested

What we learned

Condensate pump failure vs. blocked drain pipe.

Wall-mounted units drain condensate by gravity. They don't need a pump.
Concealed units are often installed where gravity drainage isn't possible. A pump lifts the water out. If it fails, water backs up and overflows the tray.
Scale and algae build up inside the pump chamber over years. The impeller gets harder to turn until it seizes.
Flushing the pump chamber with a descaler once a year prevents this. It's far cheaper than a pump replacement.

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