Mini-Split Condensate Pumps: Placement, Sensors and Lift

The short answer

Ductless indoor units often can't drain by gravity. Mini-split condensate pumps are small enough to fit inside the unit or the line set cover, and many use sensors rather than floats, with an alarm contact to stop the unit if water backs up.

Pumps we cover

Aspen Silent+ Mini Aqua: capacitance sensing, as quiet as 16 dB(A).
Aquastrong CDS036: 33 ft stated lift.
FUJIWARA FUJ-L: 32 ft stated lift.

Placement

Keep the pump below the unit's drain outlet.
Route the discharge up first, then let it fall to the drain.
Wire the alarm contact to the unit where possible.

Products mentioned

Mini-split · Aspen

Aspen Silent+ Mini Aqua Condensate Pump

Variable speed, 16 dB.

Aspen

Mini-split · Aquastrong

Aquastrong CDS036 Mini-Split Condensate Pump

33 ft head, 9.6 GPH, 20 dB.

Aquastrong

Mini-split · FUJIWARA

Fujiwara FUJ-L (FUJ-40L) Mini-Split Condensate Pump

40 L/h, 33 ft, probe sensing.

FUJIWARA

Questions readers ask

Are mini-split condensate pumps noisy?

Some are very quiet; Aspen states 16 dB(A) for the Silent+ Mini Aqua.

Where does a mini-split pump go?

Inside the unit, in the line set cover or below the unit.