It’s hard to appreciate how important a sump pump is to protect a home without understanding how they actually get the water from the sump pit out of your home. There are a lot of design elements that are unique to the job a sump pump must do.
This is a sump pump. In basic terms it has 6 main components; Float, Switch, Motor, Housing, Impeller, Volute. The cost, performance, and longevity of these pumps is dependent on the materials, quality, and configuration of these key components.
The float: This buoyant bulbs as the water rises and falls. In this image, it rides up and down on a metal shaft. When it reaches the top it pushes the switch lever up turning on the pump. When the water level falls and the bulb sinks it hits the bottom lever pulling the switch off. Solid floats resist waterlogging and are more reliable over time. Some pumps use tether floats that have internal metal balls and switches. The idea is the same; water rises and the pump turns on, waterfalls and it deactivates.
The Switch: The float moves a lever which activates or deactivates the power switch. Like a light switch, it connects power to the motor. These components wear over time and are the #1 reason that sump pumps fail. The most reliable mechanical switches on the market are tested to 1,000,000 cycles. For homes on or near a water table, the pumps can run every few minutes and the cycles add up fast!
The Motor: Residential sump pump motos range in power from 1/3 HP up to 1 HP. Pump horsepower is the main determinant in how much water the pump can move in a given time. While they do not run constantly, sump pumps can move water at a rate of up to 100 gallons a minute!
The Housing: That sleek cylinder that covers the motor and stretches from the switch cap down to the volute is called the housing. Housings keep the water away from the motor (remember – water and electricity do not mix well) and acts as sound insulation. Since they have to survive in a wet environment housings are often made of thermoplastic, epoxy-coated steel, stainless steel, or coated cast iron. The denser heavier cast iron provides the most sound and thermal insulation.
Impeller: It’s the same as a propeller – but different. The impeller attaches to the motor via a drive shaft and as it spins it moves water through the volute and out the discharge pipe. There are different impeller designs suited for different volutes. Some impellers can pass solids, some move more water. They are purpose-designed and engineered!
The Volute: This is the bottom line. Heavy cast iron volutes give the pumps a sturdy base to sit on and withstand the high pressures generated by strong motors moving water. Top Suction volutes allow water to come in ABOVE the impeller. Top suction reduces pump failures from a negative pressure situation called ‘Air Lock’. Bottom Suction volutes bring water in via a hole in their bottom, BELOW the impeller. By design, they can pass small solids but they can suffer from ‘Air Lock’. This requires a hole in the discharge pipe that leaks water back into the sump pit.
The last piece is a discharge pipe that attaches to the volute and routes the water out of your house.
Now you know the basics of the Sump Pump. But do you know what happens when a sump pump fails – and why they fail? That is the central point for the next article.
Soggy Bottoms – When basements flood.
Basements flood for several reasons. Some are preventable and some are not. Catastrophic flooding from historic rains and rivers topping their banks deliver inevitable water intrusion. Coastal flooding from weather events like hurricanes, bomb-cyclones, and nor-easters are difficult to protect against.
Cleaning out floor drains in mechanical rooms, keeping tree roots away from sewage lines, and treating septic tanks should all be routine maintenance for homeowners. So should maintaining the sump pump.
Across the country, drain tiles are collecting water from underneath and around home foundations and channeling it into millions of individual sump pits for eventual evacuation. This process continues rain or shine 24/7/365. Water goes where water wants to go. And it wants to go into your basement.
Most sump pumps have a 1-3 year warranty but can last longer. That lifespan depends on a lot of factors with the main one being how many times the pump has turned off and on. High-quality sump pumps can cycle on and off up to and beyond 1,000,000 times. Lower-cost models may only last a fifth of that. Like all mechanical devices sump pumps eventually, stop working. Most of us discover that the sump pump stopped working around the same time we discover ankle-deep water soaking our basement carpet and couches.
Sump pumps are electrical appliances, so when the heavy storms come in and take down the power grid they stop working. This is one of the most dangerous situations for a finished basement. As the driving rain saturates the ground with water, the drain tiles collect it, and the sump pit fills up… fast.
According to Homeadvisor the cost range to repair, restore, and replace a flooded finished basement is $25,000-$50,000. (https://www.homeadvisor.com/cost/disaster-recovery/repair-water-damage/)) But in many cases, homeowners can avoid these situations by taking some basic precautionary steps.
- Identify when you last replaced the sump pump. Can’t remember? Then it’s time to replace it.
- Upgrade an existing sump pump with a stand-alone battery back up pump.
- Replace the existing hardware with a combination primary + backup sump pump system.
Premium digitally connected basement protection systems offer the ultimate level of protection for finished basements and their contents. These systems leverage the power of IoT and integrated sensors to communicate critical information to homeowners from the darkest corner of the basement. These systems can transmit information on the level of water in the sump pit at any given time. They also monitor the health and charge level of the battery. Like all batteries, the ones in basement protection systems lose their ability to hold charge over the years. While they may be ‘full’ they may only be able to hold a portion of their original power capacity when they were new. It’s not enough to know you have a battery back up in place – you have to know that it will work when the power goes out. Like a smoke detector, you need a good battery for it to work.
While sump pumps can not protect against catastrophic floods or sewage line problems, maintaining your sump pit and sump pump are easy ways to reduce your flood risk. Today is the day – check your battery, check your sump pump, keep your basement and its contents safe and dry.