Why does the pump only drain halfway?

  • This is a normal operation for the pump. 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 VCMA?  

  • 50/50 water and vinegar.  

  • Cycle through the mixture 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 condensate pump for, and do I have to use them?

  • They 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. 

  • Only available on the S models 

What is the difference between the VCMA-15 and VCMA-20?  

  • The numbers 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 our condensate 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 VCMA turn 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? 

  • Use when the surrounding area can be damaged if the pump overflows. 

  • They 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 VCMA? 

  • This alarm requires a 9V battery. Cut the ends of the sensor to expose the wires. Then connect them to the 2 wires of the alarm.     

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

  • Finally, 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.