Do I Need a Condensate Pump?

Do you need a condensate pump for your ductless mini-split heat pump or air conditioner? Yes, no, maybe? If you don't know whether or not you need a condensate pump, this article is for you.

What is a Condensate Pump?

First, why do we worry about condensation in a ductless mini-split anyway?

All air conditioners create condensation (i.e. - water) as a byproduct of cooling. Because, the way they cool down your house is by reducing the interior humidity. Dehumidification creates water, and that water has got to go somewhere.

Ideally, you want that water going outside of your house. In a central air system or a ductless system, the condensation will build up in a drain pan. From the drain pan, the water is emptied outside the house via a condensate drain. In many cases, this is just a simple gravity drain.

This system mostly works great. Until you want to put an air handler in a place where a gravity drain won't work. Like in a basement. Or on an interior wall, and there is no easy way to run a drain hose outside without first going up through an attic space.

Prevent Water Damage with a Condensate Pump

Obviously, a condensate pump is the solution to these problems.

A condensate pump is a relatively small, simple device. You install it with the air handler. When the condensate builds up, the condensate pump pumps it out. It uses mechanical force to remove the water, so you don't have to worry about water overflowing the drain pan.

So, if you want to put a ductless mini-split in a location where gravity-fed drainage would be an issue, get a condensate pump. It will keep the water moving out while you stay cool.

Questions or Comments?

Do you have additional questions or comments about ductless mini-splits and condensate pumps or other HVAC products? Just let us know and we'll answer them!

12 comments (view/add)
  • K
    Posted on 10/13/2021

    How long can an AC unit run without a Condensate pump? My house gets really hot if I have my AC off and my pump failed. I can't get it fixed for a few days, I also have an outside/inside unit.

  • Dan Danowski
    Dan Danowski from Ingrams
    Posted on 10/13/2021

    An air conditioner can run operate without a condensate pump. The problem is that the condensate will buildup in the drain pan, overflow the pan, and spill into your house.

  • Bernice
    Posted on 4/30/2021

    I live in a first floor condominium, bought a new furnace and air conditioner a few years ago, was told to add bleach monthly in the condensation pump to keep it flowing during the winter as this would keep algae from building up when the air conditioner is not used during this season. Will bad odors come from the condensation pump if I do not use bleach in it? Why does some air conditioners require condensation pumps and others do not?

  • Dan Danowski
    Dan Danowski from Ingrams
    Posted on 4/30/2021

    You could get bad odors from the condensation pump, but the bigger problem would be a clog in the condensate drain. An air conditioner requires a condensate pump when a gravity drain won't work (i.e. - due to the installation the water won't be able to just flow down and out).

  • Susan Spitz
    Susan Spitz
    Posted on 4/11/2021

    I got estimates from 2 reputable companies for Mitsubishi ductless minisplit system for upstairs. These are exterior walls, 1 wall unit, 1 floor unit. 1 company itemize out a Refco condensate pump for 450.00. The other said it is not necessary for exterior walls. Is there any benefit at all to spending that money? also the floor unit costs much more than the wall unit. what is the reason for this? One company charged 479, the other 1050. Can you tell me what is a reasonable price for Mitsubishi floor mount unit? Many thanks! I have a few days until I must sign to get a state discount on the system.

  • Dan Danowski
    Dan Danowski from Ingrams
    Posted on 4/12/2021

    I'm not sure what Mitsubishi units you're specifically talking about. However, I can tell you that we sell a Refco Gobi II condensate pump for $160. You would need a condensate pump when a unit would not be able to be gravity drained (i.e. - the drain hose is angled downward so the water can just flow out). Usually, a condensate pump is not required for a unit mounted on an exterior wall. There is basically no benefit to buying a condensate pump if you don't need it.

  • David
    Posted on 3/22/2021

    What about winter time when you’re using the heat part of your mini split and what about freezing do you need to have a drain inside or can you still drain it outside the house

  • Dan Danowski
    Dan Danowski from Ingrams
    Posted on 3/23/2021

    When a heat pump is heating, the condensate would not come from the interior air handler, so the condensate drain from the air handler is not really an issue. The condensate would drain from the outside unit. It can be an issue in low temperatures which is why virtually all mini-splits will have a defrost cycle to remove any ice buildup.

  • Isaac Gonzales
    Isaac Gonzales
    Posted on 5/27/2020

    Can this unit stand free or does it attach to a wall

  • Kyle
    Kyle from Ingrams
    Posted on 5/28/2020

    A condensate pump for an air handler is usually installed inside the air handler.

  • P Okano
    P Okano
    Posted on 3/10/2020

    To where does the pump remove the water/condensation?

  • Kyle
    Kyle from Ingrams
    Posted on 3/10/2020

    It will pump it directly outside the home.

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