What Is a Condensate Pump?

In heating, ventilation, and air conditioning (HVAC) systems, condensate pumps are specialized pumps that collect and remove the water, or condensate, produced by the HVAC. If this pump fails, it could prevent your air conditioner or heater from working correctly, and even result in water damage if it goes unchecked. Below, I’ve outlined everything you need to know about condensate pumps, their care, and more.

What is a Condensate Pump?

Condensate pumps are the HVAC components responsible for removing the excess water known as condensate from the system. This prevents the water from pooling in the HVAC. They make sure the system works efficiently, while protecting the unit and building from water damage. Once the water is collected, the pump will move the water out of the unit to a different specified location.

Condensate pumps are also found in other systems, including refrigeration systems, dehumidifiers, humidifiers, water heaters, and boilers.

How Do Condensate Pumps Work?

Condensate pumps are made up of four components:

• Reservoir: This is where the condensate water collects. It can also be called a drain pan, tank, or tray.
• Float Switch: There is a floating sensor that detects the water level in the reservoir that will activate the float switch when it reaches a certain height.
• Pump Mechanism: Made up of a motor and impeller, this component moves the water from the reservoir when activated.
• Discharge Line: The water is expelled through a pipe or tube also known as a drain line.

Condensate pumps have four steps they must go through to complete the process, including:

1. Condensate collection: During normal operations, air conditioning systems produce water from the evaporator coils. Heat pumps can also produce water during the cooling cycle. Water collects in a collection tray or condensate pump reservoir. 
2. Float switch activation: As water collects in the reservoir or tank and rises, a floating sensor rises with it. Once it hits a predetermined height, the float switch will activate.
3. Pump activation: At this point, the pump turns on and the pump motor drives an impeller to create suction. This pulls the water from the reservoir.
4. Water discharge: Water is then pushed through the discharge line and sent to a specified point, such as a floor drain, utility sink, or outside.

Once the float switch drops below a certain point again, the pump is deactivated and the cycle starts again.

What Should You Do if Your Condensate Pump Fails?

If your air conditioner won’t turn on, it may be due to a failing condensate pump. HVAC systems come with safety measures, such as a safety switch, to prevent the water from overflowing from the tray or reservoir. Some even include overflow alarms to alert homeowners if the pump can’t keep up with the water. 

Some fixes can be easy, but others may require a professional. To troubleshoot your condensate pump, you should

• Check the float. In some cases, the float can become stuck and prevent it from activating the float switch. You might be able to give it a tap to get it moving again. Take this time to check the condition of the float, too. If it’s damaged, you will have to replace it.
• Look for clogs. Clogs within the discharge line could prevent the water from being expelled. Pour a cup of water into the hose or tube. If the water doesn’t come out the other end, there is likely a clog.
• Make sure it’s receiving power. Power outages and tripped circuit breakers could cause your condensate pump to not restart when the power comes back on. Make sure the pump is plugged into an outlet, and try resetting the circuits.
• Clean the condensate pump. Your condensate pump may be full of algae or debris preventing it from operating at full capacity. 
• Check the valve. Check the valve in the discharge line to make sure it is moving properly. If it is stuck, it could prevent the water from draining.
• Remove any excess water. If there is excess water in the reservoir, you should drain it right away. This will prevent water damage while also providing a temporary fix if you’re waiting for an HVAC professional to arrive.

Any component within the condensate pump could be to blame for failure to operate. For example, corrosion, low flow rates, or poor pump installation could be the reason your condensate pump isn’t working.

If your condensate pump isn’t working and you can’t identify the problem listed above, it’s highly recommended that you call a professional. This is not a DIY project for most homeowners, as you will need to have knowledge of electrical and plumbing work. If your HVAC unit is new, too, you may be able to reach out to the manufacturer or installer about your warranty.

Final Thoughts

Condensate pumps are necessary to the proper functioning of HVAC systems. If your air conditioner or heater won’t turn on, a faulty pump could be to blame. It could be an easy fix, but if the entire system has failed, you could have to replace the entire pump. If you suspect an issue with your condensate pump, always investigate or reach out to an HVAC professional right away. Failing to fix it quickly could result in additional damage to the system or your home.