Fixing Pump Problems

Eighty percent of pump problems can be fixed in minutes, saving you further inconvenience.The pump can be called the “heart” of the pond. Without it, the relaxing, rushing sound of the water over the rocks would not exist. The fish and the filtering bacteria in the biological filter also depend on the pump to provide fresh, oxygenated water.Most quality pumps should get you at least three years of maintenance-free service of re-circulating the water in your pond, so how can the pump not be working? Odds are the pump is actually fine. As a pond owner, there are a few things you can do to help detect, and hopefully fix, the problem before you call the installer or return the pump to the merchant from which you purchased it. Eighty percent of pump problems can be fixed in minutes, saving you further inconvenience. The following troubleshooting steps will help you quickly identify, and hopefully solve, the problem with a failed pump.


Proceed with the following actions until the problem is found.

    • First of all, is the pump receiving water? This sounds like an obvious question, but it’ s not an uncommon problem. Water evaporates and, if not replaced, the lack of it can affect the operation of the pump. In this situation, the pump may actually be running, but just not receiving enough water. A lot of times you can actually hear the “hum” or “gurgle” of the pump when this is happening.
    • Make sure nothing is blocking the flow of water to the pump. Large boulders, debris blocking the front of the skimmer opening, a clogged skimmer net, or clogged skimmer filter can reduce the flow of water. If you have a skimmer, make sure the water level is 3/4″ below the top of the skimmer opening. If the established water level is lower than this, the pump may suck the skimmer dry, causing the thermal shut-off to activate. The thermal shut-off will deactivate once the pump cools back down. The proper water level will then need to be established.
    • The pond is too small for the stream above it. The lowest pond must be large enough to supply enough water to start the circulation of the stream and/or waterfall. Once the pump is started, it may be necessary to add a few inches of water to the lower pond in order to account for the water used to feed the stream, pipe, and waterfalls. Lower ponds that are designed too small may not be able to supply enough water to start the streams/waterfalls. This will cause the water in the pond to drop below the opening of the skimmer upon the initial start-up, and starve the pump of water.
    • The pump may be vapor-locked. This term sounds complicated, but it simply means that air is trapped inside the pump. Pumps are designed to push water, not air so when an air bubble gets trapped, the pump becomes vapor locked. When this happens, the impeller is spinning, but water is not being pushed. Listen to see if you hear the hum of the pump. A vapor-lock can be fixed by tilting the pump, allowing the air bubble to escape from the intake.
    • Is the electrical supply operating properly? Premature pump failures can occur due to a faulty electrical supply. For example, using an extension cord, especially one over 25-feet long, may cause irregular power to the pump. This can cause performance problems with the pump, and possibly reduce its lifespan. Check to make sure all electrical connections are functioning properly. Verify that a certified electrician installed and tested the electrical while the pump was running. Oftentimes, GFCI circuits are set too sensitive, causing them to repeatedly trip the breaker.
    • Check the electric box to see if the ground fault circuit interrupter (GFCI) has tripped. The proper electrical setup for the pond should include a GFCI outlet. A GFCI is a safety device installed to protect people from receiving a shock in the event of an electrical malfunction and will shut the power down if it senses a problem. GFCIs are very sensitive and can sometimes trip during a thunderstorm or a power surge. It is also very common for outside outlets to be electrically connected to other rooms within the house, such as the bathroom. Many times, the combination of the pump running on the pond and someone using devices like a blow dryer in the bathroom can overload the GFCI and trip the breaker. Ask your electrician to make sure the electrical outlet for the pond is dedicated to just the pond.
    • Unplug the pump and disconnect the union fitting found at the top of the pump connection. The water will back-flush from the biological filter back into the skimmer. This will help flush out any debris that is clogged along the length of the pipe.