Condensate Pump Running Continuously and How to Fix It

Condensate pumps are relatively simple devices with only a handful of parts. That doesn’t mean those parts can’t fail, however, which can result in a myriad of issues. One of the most significant are condensate pumps that run continuously, which is a problem we are going to address in this guide.

Why won’t my condensate pump shut off?

If you’ve found your way to our site, you must be wondering why your condensate pump won’t shut off. Well, the good news is it’s something that can be incredibly easy to fix as long as you know where to start.

Unfortunately, there are around a dozen reasons why these pumps can run continuously and not shut off, starting with float.  Before we get started, you need to unplug the condensate pump from the electrical outlet. If it’s hardwired, you’ll need to cut the power to the unit or room at the circuit breaker box.

Condensate Pump Floats

Inside every condensate pump is something called a float. As moisture collects in the reservoir the float rises. When the float reaches a certain point, a switch is triggered which sends the water outside or to a drain. If that float gets hung when the water level rises and can’t slip back down into its natural position, the condensate pump will run continuously.

To fix this, you’ll need to get to the float assembly inside the condensation pump and clean it. If it looks cruddy with gunk build-up around the float, that’s more than likely why your condensate pump has run non-stop regardless of the water level. A quick cleaning will solve this problem, and getting to the assembly is fairly simple on some models as you’ll see from the video below.

With that in mind, switches can be tricky to replace and some condensate pumps have dual switches. This allows the pump to function if the first switch fails and ensures the float will trigger the second switch. If you believe the pump float and switch are bad, you’ll want to consider our condensate pump repair guide.

The Check Valve

Another reason for failures with condensate pumps that cause them to keep running are check valves. The aforementioned dirt and grime found on the float can also clog up a check valve, which will keep the pump from shutting off when it should.

If a check valve fails or becomes clogged, water trapped in the tube can go back into the tank causing the system to constantly cycle. Clearing the check valve is simple, and replacing these affordable parts is affordable as well providing you can find the proper type of valve for your pump.


Condensate pump Lines

Condensate pumps draw excess moisture from furnaces and air conditioners, but they have to have a discharge line to function properly. When the reservoir of the condensate pump becomes full and the float engages the switch, the pump begins to send water through the discharge line.

These lines are typically made of clear vinyl tubing, which is durable but can experience clogs. That means you may need to remove the tubing and give it a thorough cleaning if you see mold or mildew build-up in the discharge line.

A clog can happen quickly when this occurs, and any other blockages can be cleared with a bit of air. Have you or anyone else recently serviced the condensate pump in your home? If so, check the placement of the lines. A poorly placed tube that’s inserted too far into the pump can potentially cause the float to stick on some models.

What happens when a Condensate Pump doesn’t shut off…

When any appliance or HVAC component runs when it shouldn’t bad things are bound to happen. When water is involved, those issues can be significant – especially if you’re away on vacation. The only term you need to remember with a condensate pump that won’t shut off is damage. The unit itself can be damaged, but so can a variety of other things.

If a condensate pump does not shut off and runs continuously, the pump will burn out. That means you’ll have to either repair the pump or replace it entirely, neither of which is ideal. The bigger issues come into play with leaks, however, as even though the pump isn’t working, water still needs somewhere to go.

When you have a stuck float or clog, water can build up and leak onto the floor around the pump. If not caught and corrected quickly, this can lead to mold. Mold remediation is considerably more expensive than replacing or repairing a condensate pump, so it pays to keep an eye on these pumps from time to time.


A condensate pump may be a relatively simple device, but a faulty switch or undersized unit can lead to problems wherever it’s installed. Even the best condensate pump typically only lasts 3-5 years, so we highly recommend performing routine checks and giving these pumps a thorough cleaning several times each year.

Related Article: 4 Common Furnace Condensate Pump Problems & How to Fix?

Condensate Pump FAQ

Q: Can you unplug a condensate pump?

A: Yes, but only for maintenance. If a condensate pump has been installed on your system it’s there for a reason and should be left on while your unit is running.

Q: Should my condensate pump be noisy when running?

A: All condensate pumps will put out a degree of noise, but some are louder than others. With that in mind, you should not hear the pump running if it’s located in a basement or attic, and not directly outside of a living space.

Q: How long should a condensate pump normally run?

A: That all depends on how bad the condensation is on your unit. It could run several times each day or a few times a week depending on the environment where it has been installed.

Q: Will a whole house humidifier cause problems with condensate pumps?

A: Regular humidifiers in a living area can keep moisture contained to those spaces while whole house humidifiers can raise levels throughout your home. When this happens, it can affect the condensate pump to a degree.

Q: How far can a condensate pump push water?

A: Lift is generally the measurement you’ll want to look for with condensation pumps although horsepower is important as well.

Written by

Rene has worked 10 years in the HVAC field and now is the Senior Comfort Specialist for PICKHVAC. He holds an HVAC associate degree and EPA & R-410A Certifications.

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