What is a Mini Split Condensate Pump?

Many types of HVAC systems produce water, whether it’s from an air conditioning system, refrigeration, boiler furnace, or steam system. Removing that excess water is critical for the system to function.

This is where the condensate pump comes in. In this guide, we discuss their function, and how to choose the right condensate pump for your AC or mini split.

What is a Condensate Pump?

A condensate pump is a special type of pump that deals with the condensate (excess water) generated by an air conditioning system, such as a mini split. 

The water is produced during the condensation process, when the air is passed through the cold evaporator coil. The moisture then accumulates on the coil and drips down into a collection area. Most systems simply allow gravity to dispense of the condensate into a drain pan or drain line. However, if you cannot drain with gravity, you must use a condensate pump to get the water out. 

How Does a Condensate Pump Work?

A condensate pump consists of three major parts: the reservoir, float, and pump. They all work together to collect and drain the condensate.

As the collected water rises within the reservoir, it lifts the float. The float in turn activates the pump to siphon the water through a drain line and out to the home’s exterior or to another drain. As the water is drained, the float descends and automatically turns off the pump. 

Most condensate pumps use 110 volts. They are often plugged into a standard wall outlet located close to the AC unit. 

The reservoir tank on a traditional pump typically ranges from 0.5 to 1 gallon. Some smaller pumps may not have a reservoir. Instead, they are placed directly on the drain pan of the AC to pump out the collected water. There are also compact pumps designed specifically for use with mini splits that take up much less space.

Why is a Condensate Pump Important?

• It ensures proper drainage of condensate.
• Drainage is critical to the continued operation of your AC system. A frozen evaporator coil or blocked compressor due to excess condensate is the common cause of many AC problems.
• The pump prevents water from dripping onto the floor or in the attic and causing water damage.

How to Choose a Condensate Pump for your AC or Mini Split

1. Choose the right type for your AC

There are condensate pumps that are used for specific types of air conditioning systems. Identify what type of AC you have, such as ducted or split, and start from there.

Also consider the specific model. Floor, wall-mounted, and ceiling cassette units may have their own types of condensate pumps.

2. Determine the cooling capacity of your AC

This is needed to estimate the amount of condensate discharged per hour. Larger AC units typically produce more condensate, requiring pumps with bigger discharge capacities.

Consult your owner’s manual or AC specs to determine the cooling capacity.

3. Local climate

The amount of condensate discharged can differ significantly between dry and humid climates. The water generated in humid areas or tropical zones can be double that of drier regions. Homes located in humid areas may need a high performance pump designed for humid climate conditions.

Other Features to Look for in a Condensate Pump

Installation preference

A condensate pump can be mounted in many different ways. It can be installed next to the unit, below, inside, or remotely above the AC.

For indoor settings, you may have a specific location preference to hide the unit, make it more accessible for cleaning, or have an obstruction.

Two-stage switch

Some condensate pumps feature a two-stage switch to guard against overflow. As the tank gets filled to the first stage, the pump is activated to drain the tank. 

If the condensate level continues to rise because the pump has failed or the discharge is blocked, a second stage is engaged. The pump then either shuts off automatically or triggers an alarm.

Noise level

Like all pumps, condensate pumps emit noise during operation. This is measured in decibels, or db(A). The lower the number, the less noise it generates during use.

Recommended AC and Mini Split Condensate Pumps

For wall-mounted mini splits:

Refco GOBI-II 120/240 VAC External Condensate Removal Pump

This handy little condensate pump is designed for use with wall-mounted mini splits. It has a compact size of 11 1/4″L x 2 1/8″W x 2 1/8″D, so it can be placed unobtrusively below indoor wall units. Since it mounts directly below the unit, it is convenient to install and easy to replace.

But don’t let its size fool you! It can remove up to 11 gallons of water/hour, and is compatible with almost any system from 6,000 BTUs up to larger 120,000 BTU units. A USB port allows access pump history, and wireless access is available as an option.

The Gobi-II uses a standard 120/240VAC; 50/60 Hz auto sensing universal power input and will operate with water temperatures from 41° – 77°F (5° – 25°C) and ambient air temperatures from 37.5° – 104°F (3° – 40°C). It comes with a 1/4″ x 3.3′ discharge hose.

For universal installation:

Refco COMBI Condensate Removal Pump – Universal Voltage

This flexible condensate pump is designed to accommodate all types of mini splits. It has flexible installation options including interior mounting of both the water sensor and the pump, either side by side, or vertical water sensor installation. Additionally, the water sensor can be installed in the indoor unit with the pump installed either next to the unit or in the ceiling.

It can accommodate small mini splits with 6,000 BTUs all the way up to larger systems with 120,000 BTUs. The pump can remove up to 11 gallons of water/hour, and uses a digital water level sensor for quiet pump operation.

The Combi uses a standard 120/240VAC; 50/60 Hz auto sensing universal power input. The Combi will operate with ambient air temperatures from 37.5° – 104°F (3° – 40°C) and water temperatures from 41° – 77°F (5° – 25°C).

At Total Home Supply, we carry a range of condensate pumps designed for different AC systems, as well as replacement filters and drain tubes. We also carry condensate pumps for dehumidifiers.