Why does my Little Giant VCMA pump only drain halfway?

  • It is normal for the Little Giant VCMA pump to only drain halfway. It ensures the pump does not run dry, and the impeller will remain submerged.  
  • There is an ON and OFF switch. When the ON gets activated, it pumps out water until it reaches a level of about half the bottom tank. 

How do I clean my Little Giant VCMA pump?  

  • Clean the Little Giant VCMA pump with a 50/50 water and vinegar mixture. 
  • Clean the pump once a year, or twice if you have a lot of slime build-up.  

IMPORTANT: Chlorine will damage the pump. 

What are the 2 black wires on my Little Giant VCMA pump for, and do I have to use them?

  • The 2 black wires on the Little Giant VCMA pump are for a high-water safety switch that can be wired to shut down the unit producing the condensate.  
  • They activate a low voltage alarm for high water levels.  
  • The safety switch is optional and does not need to be hooked up for the pump to operate correctly.
  • This is only available on the S models.

What is the difference between the Little Giant VCMA-15 and VCMA-20 pumps? 

  • The numbers on the VCMA-15 and VCMA-20 pumps are related to the maximum head the unit can pump the condensate. The models handle different flow rates and head. 
  • They also contain different impellers. 

What does the nomenclature for my Little Giant VCMA pump mean (UL, ULS, ULST, ULT)?

  • UL: Underwriters Laboratories listed 
  • ULS: UL listed with high water level safety switch
  • ULST: UL listed with high water level safety switch with 3/8 in ID tubing
  • ULT: UL listed without high water level safety switch with tubing  

Why won’t my Little Giant VCMA pump turn on?

There are a few reasons your Little Giant VCMA pump isn't turning on.

  • If applicable, remove the carboard tab from the cover that comes in the pump that keeps the switch in place.
  • Check that the switch in the pump is in between the 2 pins when you open the motor cover.  
  • Verify the switch is pressed all the way down. 

When do I need a ULS condensate with my Little Giant VCMA pump?

  • Use a ULS condensate with your Little Giant VCMA pump when the surrounding area can be damaged if the pump overflows.
  • ULS condensates are used for high water capacities. They have a second switch that is integrated inside the model that can be used to shut down an AC unit or sound an alarm if water gets too high.  
  • It is not required in some applications.  

What alarm goes with the Little Giant VCMA pump?

An alarm that can be paired with the Little Giant VCMA pump is the 513379 | Little Giant:

A white device with a wire attached to it Description automatically generated

NOTE: This alarm requires a 9V battery.

  1. Cut the ends of the sensor to expose the wires.
  2. Connect them to the 2 wires of the alarm.
  3. Switch the setting from NO to NC.
Our Brand Promise

There’s a reason we’ve been the go-to pump for HVAC, Plumbing, Pool, and Hydroponics professionals for generations: experience. For 80 years, Little Giant® products have stood the test of time, pumping a steady flow of proven reliability in the most demanding applications.