Most Common Sump Pump Problems

Simply stated, every home should have a sump pump. While we’ve all heard about, or perhaps even experienced, a flooded basement due to a sump pump problem, the benefits still outweigh the risks. The mechanical nature of the pump makes it susceptible to wear and tear, so understanding some of the common sump pump problems to watch for will help you avoid flooding.

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Today’s sump pumps are typically submersible which means they are sealed units that sit below the water in the sump pit. The electric motors on these are quieter and more efficient than the old pedestal style that was once popular. While they are generally more reliable and an excellent form of basement waterproofing, there is no such thing as a fail-proof sump pump. Here are the most common issues:


It seems fairly basic that the “electric” sump pump needs power to run. Surprisingly, this happens more often than you might think. A circuit breaker may have tripped or the unit may have been accidentally unplugged. Always make sure the power cord is unbroken and securely plugged into the dedicated outlet. Power outages can occur at any time, especially when you’re away from the home. Having a battery backup pump or high-water alert on your home security system will safeguard your property in case power is lost.

Backup systems range in pumping capacity from 2,100 gallons per hour to 3,000 gallons per hour. Vertical float switches should be fully adjustable and units that can be installed with two maintenance-free batteries will have longer run times. This is a wise investment.


The function of a float switch is to activate the pump when the water reaches a certain level in the pit. As an essential component of the system and the part most likely to break first, it’s a good idea to select a sump pump with a replaceable float switch. There are four types of floats: vertical, tethered, diaphragm and electronic.

  • A vertical action float is attached to a rod that floats above the water. The float rises with the water and turns on the pump once the water reaches a certain level. This type is generally efficient and rarely gets stuck like some other styles.

  • A tethered float is used primarily for pedestal pumps. It hangs from the pump and sits on top of the water. Similar to the vertical float, when the water rises to a certain level, the pump is activated. Tethered floats often hang up on the sides of the sump hole and allow the water to overflow into the basement. Another common problem is the loss of buoyancy or sinking due to dirt accumulation.

  • Diaphragm switches are generally the professional’s choice. They are more expensive than other styles but very reliable. The switch turns on with increased water pressure and turns off once the water is pumped out. There’s no float to get caught and a large volume of water entering the pit will not trigger the switch prematurely.

  • The electronic switch uses a probe wire to detect rising water instead of a float. Often a second wire is used at a higher level to activate a backup pump or set off a security system alarm.


Residential sump pumps are rated with horsepower and pumping capacity in gallons per minute. The most common sizes are 1/3 horsepower that pump 35 gallons of water per minute and 1/2 horsepower that pump 60 gallons per minute. Choosing the proper size for your application is important – too large or too small will result in a shorter lifespan. A general rule of thumb is to replace your pump with the same size that’s installed. Upgrading from a 1/3 horsepower to a 1/2 horsepower sump pump could be considered if your home is in a high water table. In this case, the weeping tile will drain faster and the pump will run too often. Another situation that might call for a larger size is when you have a high vertical lift or long horizontal pipe run. Anything over 10′ vertical lift or 25′ horizontal run will result in a loss of water flow due to friction. A larger pump will offset this issue.


Homeowners who neglect to follow the manufacturer’s sump pump installation instructions risk pump failure and a flooded basement. Make sure the pump is sitting on a solid surface. Clean any dirt or gravel away from the crock bottom to avoid interference with the float switch. In addition, installation of a check valve is recommended to prevent water from flowing back into the impeller. If this happens, it can unscrew off the shaft and malfunction. A small relief hole should also be drilled in the discharge line to release air pressure. Failure to do so will force the pump to work too hard and likely shorten its lifespan.


You may not notice a problem with your sump pump operation during the warmer seasons but harsh winter temperatures can lead to all sorts of trouble. Incorrect pipe pitch is the leading cause of blockage. If it’s not angled properly, the water will collect inside and freeze. As the pit fills with water, is prevented from discharging properly and has no place to go, you’ll have a major mess on your hands.


Sump pumps require very little maintenance but that doesn’t mean “no maintenance.” Manufacturer recommendations vary but it should run every two to three months. During the drier summer season your pump won’t run very often. Forcing it to operate by pouring some water into the crock occasionally will keep everything lubricated and running smoothly. At the very least, make sure you check its operation prior to the rainy season.

Some other regular maintenance tips include:

  • Make sure the water is discharging outside.

  • Look inside the crock to make sure water is being pumped out. A disengaged impeller or backward check valve might be the problem.

  • Clean out the discharge pipe air hole.

  • Be sure the float is unrestricted and working properly.

  • Clean the pump by running a vinegar solution through it.

  • Replace the back-up pump battery every three years.

  • Listen for odd noises during motor operation.


Like any mechanical appliance, there’s always a possibility of a manufacturing defect. While this is a fairly uncommon occurrence, it has happened. Be sure to test the pump’s operation upon initial installation, register the warranty with the manufacturer and retain your receipt for future claims. If you notice a problem, contact the manufacturer immediately. Depending on the warranty terms or time period, you may be entitled to replacement parts or a completely new pump.


It’s possible that your sump pump will run smoothly for years. Don’t be lulled into a false sense of security and assume you’ll never have any problems. The average lifespan for a residential sump pump is five to seven years. If yours has exceeded that age, consider yourself lucky and replace it before trouble starts. Replacement pumps run between $150 and $400, depending on size and output capacity. If you have enough of installation experience you can complete the project in a couple of hours and save yourself extra installation costs.

Keeping your home and family protected from water damage, flooding and health concerns can be as simple as keeping your sump pump operating properly. By watching for these common problems, you should have years of trouble-free operation. Remember, if you have any questions or just want some additional peace of mind, the professionals at Aquamaster Drain, Plumbing & Waterproofing can provide expert advice. Low-cost maintenance plans, pump replacements and back-up accessories are also available if needed.

About Aquamaster Basement Waterproofing

Aquamaster Basement Waterproofing is your full-service plumbing and basement waterproofing company assisting the Greater Toronto Area residents. We offer services such as drain repair, drain cleaning, basement waterproofing, sump pump installation, basement underpinning and more.

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