Installing Condensate Pumps in Mini Split Systems
Managing condensate in mini split systems comes down to two primary methods: gravity drain or using a condensate pump. While using a gravity drain is the simpler route, not every install allows for the slope needed. That’s where condensate pumps come in—and wiring them properly is key to avoiding callbacks and communication errors.
Gravity Drain: The Simplest Solution
When space and layout allow, a gravity-fed line is the most straightforward method. Just run a PVC or vinyl drain line on a consistent downward slope to a floor drain or approved exit point. It's efficient and requires no power or moving parts.
When to Use a Condensate Pump
In cases where gravity drainage isn’t feasible—such as in wall-mounted or ceiling cassette systems—contractors rely on condensate removal pumps. These pumps automatically remove water from the drain pan, but wiring must be handled carefully, especially in Mitsubishi and Breeze33 mini split systems.
For compact installations, consider the ClearVueâ„¢ Mini Condensate Pump, designed specifically for ductless (mini-split) systems. Its super quiet operation and Floatless Sensorâ„¢ technology make it ideal for residential applications.wesupplytrades.com
Alternatively, the Little Giant® 554200 VCC-20ULS Automatic Condensate Removal Pump offers efficient and reliable removal of condensate from HVAC systems, with an impressive flow rate of 80 gallons per hour.
Wiring Mini Split Condensate Pumps
Here’s a breakdown of wiring specifics for both brands:
Mitsubishi Units:
- S1 and S2 = Line voltage
- S3 = Communication
- S1 = Always 110VAC
- Most pumps require 240VAC and should be wired to S1 and S2
Breeze33 Units:
- 1 and 2 = Line voltage
- 3 = Communication
- Communication path is between 3 and 2, while 1 provides 110VAC
Wiring the Safety Switch Correctly
Nearly all condensate pumps include a built-in safety switch. To avoid system errors:
- Only break the S1 wire (or terminal 1 on Breeze33) when wiring the safety circuit
- Never break S2 or S3 (or terminals 2 or 3), as this can interrupt the communication path and trigger communication errors
For added protection against condensate overflow, the Safe-T-Switch Condensate Overflow Shut-Off Switch detects clogged A/C condensate drains and shuts off the system to prevent water damage.
Alternative Safety Methods
Other less common methods include:
- Breaking the thermistor wire (on Mitsubishi units with a branch box)
- Using a unit’s overflow jumper wire, if provided
At WeSupplyTrades, we carry trusted mini split condensate pumps and the accessories to go with them. Our team knows these systems inside and out—because we’ve installed them ourselves. Explore our full range of condensate supplies to find the right fit for your installation needs. Email our support team at [email protected]—we’re ready when you are.