Sump Pumps - Keep Your Basement's Best Friend Working

Sump Pumps – Your Basement’s Best Friend

Water is often the most troublesome and costly issue that occurs in homes. Spring and summertime are generally the wettest due to spring and summertime thunderstorms so now is a good time to evaluate your exterior and interior drainage performance. There are many simple things that home owners can do to help prevent water from entering the home from the start, such as proper exterior grading, properly sloped clean gutters, and extending downspouts to discharge well away from the home.

This photo was taken during a recent inspection near the top of the basement steps. The line appears to be the ‘high water mark’ left after the basement flooded likely, at least partially, due to a failed sump pump and heavy rain.

I found this flooded basement during an inspection a few years ago. There was mud throughout and standing water puddles in various areas of the basement. It was evident that the basement had taken on a good amount of water recently via rust stains on the water heater (look in the photo’s upper left corner), furnace, steel support columns, etc. and water stains a few feet up the basement walls. The seller had 2 dehumidifiers running when I arrived yet the seller’s disclosure said the basement had never taken on water before.

Most modern homes have a buried (approx. 10~12′ below grade) built-in drain system called weep tile. This is tubing with small openings installed around the exterior perimeter of the bottom of your home’s foundation walls. This helps control water to help prevent a wet basement. Water infiltration into a basement can cause structural damage, mold, and/or damage to appliances in your basement, such as your water heater and heating system as well as to items stored in your basement. This buried tubing is also called a ‘weeper’ for short and sometimes has a fabric ‘sock’ installed over it to help prevent it by being clogged by dirt or gravel. The tubing then normally runs through the footer and discharges into a sump pit. The sump pit (sometimes called a ‘sump crock’) normally has a plastic liner. A pump system is needed to remove the water that accumulates in the pit and discharge that water to the exterior far from the home’s foundation.

“Preventing A Wet Basement” is a related article that you may find useful in protecting your home by helping to keep your basement dry.

Sump pumps have a float mechanism that senses when the pit’s water level gets high or low and turns the pump on or off accordingly. The two most common sump pump types are submersible and pedestal. A submersible pump sits down within the pit and is designed to be located within water. A pedestal pump has a low intake with a center pole; the pump motor itself sits above the water level as the pump is not meant to get wet. With either type of pump, an intake opening at the bottom draws in water and pumps it out once the float switch activates the pump based upon water level. These pumps are normally powered by the home’s power (120 Volts AC).

This photos shows a submersible sump pump. The float mechanism hangs off to the side.

Sump pump system (submersible pump) with a backup sump pump system installed (notice the 2 separate discharge pipes for each pump).

A battery backup system (an independent DC powered sump pump) is a wise addition in case there is a power outage or the primary pump fails due to malfunction (age, blockage, etc.). A power loss would mean that the main sump pump wouldn’t operate and the water could accumulate and overflow your sump pit and likely flood the basement. If the basement is finished, a battery backup is considered a ‘must have’. Think of how much damage will occur to a finished basement if the primary sump pump fails and inches or feet of water accumulated in the basement. Wall and floor coverings, furniture, and appliances could all be damaged and possibly warrant a total gut of the finished basement. Also, if water comes in contact with the electrical receptacles, electrocution could occur. Even if the basement is not finished, anything stored on the basement floor could get water damaged.

A sump pump could be considered your basement’s best friend. It has a huge job to protect your home. A battery backup pump system is a secondary sump pump that runs on a deep cycle battery system that can maintain a charge over a period of years. Depending upon the system installed and how long the pump needs to run, the battery backup system may be able to run (on and off on occasion) for 4+ hours or even for a few days. Many of these have an alarm that monitors the condition of the battery and can alert the home owner if the battery is failing which would prevent the backup pump from running. The backup pump sits just above the level of the main pump; if the water continues to rise (due to the main pump not turning on), the still rising water should trigger the backup pump and pump out the water.

Battery powered back-up sump pump (photo courtesy Bulldog). This is a backup (DC powered) sump pump system that can work in conjunction to a regular (AC powered) sump pump system.

There are also sump pumps that exist that use no power but operate by the pressure of the public water system. A water supply pipe is connected to this type of pump and, when the water level in the sump pit rises, a siphon is created due to the supply plumbing’s water pressure and discharges the sump water from the building. Of course, this will not work in a home on a well as the well pump also needs power to operate.

As part of a home inspection, the home inspector should provide some helpful guidance such as recommendations to help keep water out of their home.

Some of the basic things that every home owner should do to help prevent water in their basement or crawl space includes ensuring proper exterior grading away from the home’s foundation, ensuring that gutters and downspouts are clean of debris, ensuring that the downspouts and sump pump pipes discharge at least 4′ from the home’s foundation, and installing covers on any basement window wells.

No matter what type of sump pump system you have in your home, it is wise to check the system on a regular basis (at least monthly is suggested). Here are some tips:

Make sure that the pump is powered – an unplugged pump or unpowered receptacle spells trouble. If the sump pit is already sufficiently filled with water, manually test the pump by lifting the float. If there is no water in the sump pump, pour 5~10 gallons of water into the sump pit and make sure the pump operates normally. Running a pump when dry (the sump pit little or no water in it) can damage the pump. Also, make sure that the pump sits vertically within the sump pit; a crooked (non-plumb) pump may not work reliably.
Ensure that the float is not obstructed – the float is a plastic ball that senses the water level and controls the ON/OFF operation of the pump. If the float can’t operate freely without obstructions, the pump may not turn on as the water level rises. The float sits on the water’s top and triggers the pump to turn on or off based upon the rising or lowering water level in the pit. Ensure that there is no debris in the sump pit preventing operation/movement of the float or blocking the pump’s ability to suck water. Cleaning out the screen at the pump’s base (where it sucks in water) may also be needed. If the screen is blocked by mud, debris, etc., water can’t get pumped out. A cover over the sump pit can prevent toys or other items from falling into the pit which could prevent pump operation.
Is the discharge pipe secured and a rigid material or is it loose flex pipe? A rigid pipe (such as PVC) primed and glued and secured to the wall along its vertical run up the basement wall immediately near the sump pump is the best option. On a few occasions, I’ve seen flexible, corrugated plastic pipe that simply hangs between the exterior discharge point and the pump. The force of water in the drain pipe when the pump turns on may cause the discharge pipe to become unstable and possibly come loose spraying water around the basement. I’ve seen it and it’s not pretty. A proper rigid secured drain pipe is much more reliable.
Ensure that there is an in-line check valve installed – this is a one-way valve installed in the drain line between the pump and the location where the discharge pipe exits the home. It allows water to only go in one direction. Ensure the check valve is installed in the proper direction; there’s an arrow on it and it should point away from the pump. This valve is important because when the pump stops each time, there is still water in the discharge pipe between the pump and the high point of the discharge pipe that doesn’t exit the system. A properly functioning check valve will stop the water inside the pipe from falling back down (by gravity) to the pump. Without a check valve, this water will re-enter the sump pit and repeated cycle the pump. This will make the pump continue to run unnecessarily and likely wear the pump out prematurely.
Route the discharge pipe at least 4’ from the home (further is even better!). If the sump pump discharge pipe simply passes through the foundation or siding and stops, this water drains along the foundation again. This could attract insects/rodents to the building plus this water will likely find its way right back into the sump pit where it will again need to be pumped out in a never ending cycle. The discharge point should not be under a deck or porch as this water could accumulate and allow for ground settlement (affecting the deck or porch), may attract insects, and/or lead to wood rot of the deck or porch structure.
Ensure that the sump pump is plugged into a grounded receptacle. Modern sump pumps are grounded appliances (with a grounding pin on their plug) and should be connected to a grounded receptacle for safe operation. You would need a receptacle tester to actually make sure a grounding wire is connected to the receptacle within the receptacle box. Simply seeing a 3-wire (grounded type) receptacle doesn’t necessarily confirm the receptacle is actually grounded. Modern electrical standards require that this receptacle to also be GFCI protected for safety reasons.

The life expectancy of a sump pump can vary widely depending upon the size (horse-power rating), whether its submersible or pedestal, how much dirt/gravel exists in the sump pit, and most importantly, how much use the pump gets. A pump that runs every 15 minutes due to a high water table around the home is going to have a much shorter life compared to one that only runs hourly on very rainy days. Also, check with your city/township/borough as many areas now forbid discharging sump pumps into the sewer system. Most areas require sump pumps discharge to grade outside the home.

There are recognized standards for Sump Pumps.

Matthew Steger is a Certified Level 1 Infrared Thermographer, an ASHI Certified Inspector (ACI), and an electrical engineer. He can be reached at matthew@thehomeinspectorsnotebook.com. No article, or portion thereof, may be reproduced or copied without prior written consent of Matthew Steger.