How can I keep my submersible pump running for as long as possible?

by: Demi Fortuna

Your pump represents a sizable investment in your water feature, so you may want to keep it alive as long as possible. There are a number of techniques to safeguard your pumps. Depending on the type of pump you have, some tips will be more critical than others, but all the techniques below will prolong the lives of any pump.
Direct Drives - These strong, durable pumps are a favorite of contractors because they withstand abuse and neglect pretty well, but there a couple of situations that will shorten their lives quickly. Most damaging are conditions that lead to overheating. Direct Drives in skimmers are especially vulnerable to overheating when the filter media, whether bags, mats or pads, are neglected. Left too long between cleanings, clogged media block the flow of water into the pump chamber; the water level around the pump drops. Air around the top of the pump removes heat 100 times less efficiently than water, and the pump starts to overheat. Most pumps are protected with a thermal switch that turns them off when they're about to melt down, but the switches have a limited lifespan; after a certain number of cycles they fail, and that's the end of the pump. This is the number one cause of skimmer-mounted pump failure.

Tip #1 - Keep the bags, mats or pads in your skimmer clean, to keep your skimmer-mounted pump fully submerged at all times. Alternately, use a skimmer with brushes, which allow water to bypass between them when full of debris, keeping water flowing to the pump at all times.

Mag Drives - These little pumps are almost maintenance-free. They are hard to overheat as long as they are kept submerged, and can run for years without failure -- IF they are kept clean. Two things will kill them; one can be repaired, one can't. The first situation is pretty common - a small piece of mulch or twig gets past the prefilter and jams the impeller. When the flow stops, most folks' first impulse is to unplug and re-plug the pump, to free the impeller, but this can backfire and snap the ceramic shaft that the impeller spins on. Luckily, the shaft, impeller and magnet assembly can usually be replaced at a modest cost.

Tip #2 - When flow stops, unplug the pump, check for blockage and make sure the impeller can spin freely BEFORE plugging the pump back in. Use a pencil or screwdriver to rotate the impeller one full turn. If it doesn't turn freely, remove the impeller housing, find the debris and remove it. This goes for all pumps.

The second situation that's especially damaging to Mag Drives is to have the pump sitting directly in the pond, down in silt or sediment. Constantly pumping abrasive grit can wear the bushings that the impeller shaft rides in. Once worn, the shaft will start to wobble and the Mag will start to fail. Usually, the bushings are difficult or impossible to replace, so that's it for the pump.

Tip #3 - Either mount the pump in a skimmer, or keep any pump that's sitting in a pond a few inches off the bottom, on a flat stone, to keep abrasive sand out of the pump.

Asynchronous Hybrids - The popularity of these pumps is well-deserved. They are quiet, powerful, efficient and can be long-lived, if a couple of precautions are taken. Their efficiency is gained through tight tolerances between the spinning rotor and the 'can' it sits in. Any debris or deposits that build up in the space between them will eventually cause the pump to fail, either by wearing off the stainless steel cladding surrounding the copper coils, or by cementing the rotor into the can. Deposits around the rotor are the single greatest cause of Hybrid pump failure. Luckily, there is a simple, effective way to avoid an early demise.

Tip #4 - Open and inspect the pump after the first month of operation, especially in areas of hard water. If there is any evidence of hard water deposits, undiluted white vinegar should remove them with little effort. Check the pump again after another month to see if the pump will require monthly maintenance, or can go longer between cleanings. Although it does take some time and effort, regular cleaning will keep your Asynchronous Hybrid pump alive and well for years.