How To Tell If A Condensate Pump Is Working? (4 Step Guide)

Wonder how to know if your condensate pump is actually working?

Testing a condensate is a pretty simple process, and it only takes a few steps.

In this guide, I will go over...

  • Why you should pour water into the pump intake port for testing
  • Why the check valve is a common problem
  • Verifying float operation

Let’s get started with this guide!

how to tell if condensate pump is working

How To Tell If The Condensate Pump Is Actually Working?

Sometimes during home inspections, I can tell that the condensate pump has stopped working because there is water all over the floor. If the homeowner knew how to test the condensate pump to see if it is still working, some water damage may have been avoided.

The best way to tell if a condensate pump is working is to simply pour water into the pump reservoir. If the condensate pump is working, the float will rise up as you pour the water, which will activate the float switch, and the pump will audibly turn on. 

Continue reading as I go through the steps to tell if your condensate pump is working properly...

Read Also: What Are The Best Condensate Pumps?

#1. Locate A Free Intake Port & Pour In Water

In condensate pumps, there are usually 2-4 holes called pump intake ports which is where the AC condensate drain line gets inserted.

The AC drain line is usually a 3/4" pipe (white PVC) that comes from the furnace or heat pump.

There should be a few open ports (you may have to remove a small cover) so that gives you access to pour in some water without removing any piping.

If you notice that the pump reservoir is already full of water, then you can proceed to see if there is electrical power to the outlet because the float should of activated.

#2. Did Pump Turn On?

If the pump did not turn on, I would unplug the condensate pump, and verify that there is power to the condensate pump. You can plug in a lamp or some other device to see there is power.

If there is no power to the outlet, you may have to reset the GFCI switch. Condensate pumps are sometimes connected to GFCI outlets, and there should be a master GFCI outlet that you will have to reset. The master GFCI outlet will have a reset button on it that you will have to press.

Sometimes the GFCI reset button is on the breaker inside the electrical panel box. Also, just check the electrical panel to see if any of the breakers have tripped.

GFCI outlets are usually installed in areas where you deal with water like in utility rooms, bathrooms, and kitchens. You may still get a painful shock with a GFCI outlet, but it shouldn't be fatal.

Read Also: What Happens If You Don't Change The AC Filter?

#3. Is Water Draining?

After you have poured in water, and hopefully the pump turned on, you will want to verify that water is actually draining out.

The pump may have audibly turned on, but no water is pumping out. If the 3/8" discharge tubing is clear colored, then you should be able to see the condensate draining out of this clear tubing.

If the tubing is not clear colored, then you will have to find the termination of the discharge tubing to verify that water is actually discharging out of the tubing — though you should be able to feel water flowing through it.

Sometimes algae can clog piping and cause flooding in basements.

Read Also: What Are The Best Washable Furnace Filters?

how to tell if condensate pump is working (1)

#4. Discharge Strength

And even if the condensate pump actually turns on, you want to make sure that the water is draining properly — it shouldn't come out as a trickle. All of the water should drain out of the tank reservoir within a minute.

This step should be pretty easy if you have access to the termination of the discharge tubing. All of the water should drain out of the tank reservoir pretty fast since it's a small reservoir.

Another way to see how strong the water is pouring out is to remove the 3/8" clear discharge tubing from the check valve.

Check Valve

The check valve is a small plastic valve that gets connected to the clear 3/8" discharge tubing, it is about 5-inches long. This valve prevents flow in the wrong direction so doesn't go back into the tank after it has been pumped out. Basically, it is a one way water valve.

I recommend doing this step outside where water damage won't be a concern because the water will shoot straight up out of the check valve. And while the pump is plugged in, pour in water, and see how the water drains out of the check valve.

If the water is draining very slowly, or not at all, you may have a defective or clogged check valve. A defective check valve is one of the most common components of condensate pumps that go bad.

Read Also: How To Clean A Honeywell Humidifier?

Final Thoughts

Testing your condensate pump to tell if it's working isn't rocket science.

The simplest step is just pouring in water into one of the intake ports to see if the pump turns on. If the pump turns on, you want to verify that it is pumping normally and it's not just a trickle of water.

And if the pump doesn't turn on, I would first plug a lamp into the outlet just to make sure there is power. If there is no power, you may need to reset the GFCI circuit or flip a breaker at the electrical panel.

Read Also: What Are The Best AC Coil Cleaners?

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8 thoughts on “How To Tell If A Condensate Pump Is Working? (4 Step Guide)”

  1. I bought a high-efficiency furnace in 2012. When I first got it, the plastic tube from the condensate pump would have water and bubbles go through it (across ceiling to drain in PVC pipe where washer drains). I realized I haven’t seen that happen for quite awhile. Is that a sign something’s wrong with the pump? I’ve had trouble with the furnace going out several times a year. Sometimes it comes back on if I turn the switch off, then on again. I’m a senior citizen and it’s stressful never knowing if I’ll have heat. I have a service contract with DTE, and sometimes they find something to work on, but they never seem to find the source and the furnace keeps going out. The only thing that’s helped is keeping my thermostat at a high temperature 24/7 (last year 75 degrees, this year I have to keep it 76 degrees. I’d appreciate any suggestions.

    • Yes, it may be related to the furnace not draining properly. A high efficiency furnace will be constantly producing condensate, so if you don’t see any that is an issue. I’d recommend having an new HVAC contractor take a look to be honest. A high efficiency furnace with 150k BTU will produce around 11-gallons of water over an 8 hour period.


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