The sump basket in your basement's floor collects water through buried pipes from saturated ground around your home's foundation. The electric sump pump draws that water up and out of the sump pit and out of the home.
I've found a good article and a few links explaining how these systems work, how to keep them running well and backup options for when they fail:
- Your Sump Pump and You
- By Michael Salsbury
- © 2004 by Michael E. Salsbury
- If you live in a home with a basement, there is a very good chance that somewhere in your basement is a sump. In that sump, there is almost certainly a sump pump.
- What is a Sump? What is a Sump Pump?
- Around the foundation of your home and under the basement floor there are a series of pipes. These pipes channel water away from the foundation and basement walls, flowing it into a hole called the “sump”. During a heavy rain, the sump will begin to fill up with water, water that would have flooded your basement floor.
- If all you had was a sump, you’d still end up with a flooded basement in any kind of significant rain. The key to keeping the basement dry is the sump pump, which is a submersible water pump that sucks water out of the sump and pushes it far outside the home away from the foundation where it can’t harm your home or belongings. As long as you have a working sump pump, you’ll probably never see a flood in your basement.
- Why Do I Care about Sump Pumps?
- If your sump gets too “junked up” or fills with water, it won’t be long before it stops doing its job of getting water away from the basement and foundation. Soon, the sump will overflow and your basement will become flooded with water. Anything unlucky enough to be on the floor of your basement will at the very least get wet, and in the worst case be damaged or destroyed.
- My home had a finished, carpeted basement. When our sump pump failed during a particularly nasty storm, the basement floor got flooded about an inch deep. Because I was not at home when this happened, and didn’t discover it until much later, a number of valuable possessions were damaged or destroyed by the water. The carpet became “delaminated” and useless. It cost approximately $3000 to have the flood waters removed, the walls and floor dried, anti-microbial agents applied, and the humidity reduced. It cost another $1500 to have the carpet replaced. Replacing the sump pump, check valve, and having the pipes to the gutter unblocked cost another $600. I had to take 2-3 days off work to be there for the damage restoration people, the plumber, and the carpet installers. All this because of the failure of a $75-200 sump pump. Needless to say, a loss like this will open your eyes very quickly to the necessity of maintaining a sump and a sump pump.
- Basement Flood Insurance Coverage
- Our $5000+ loss was made all the worse by the fact that our insurance didn’t cover the flood. Unless you’re certain that your insurance DOES cover such a disaster, talk to your insurance agent as soon as you can. Make sure your homeowner’s policy covers the damage that a failed sump pump can cause you. Do this immediately if your basement is finished and carpeted. Trust me. We thought our policy covered this, and found out after the flood that it didn’t. This kind of expense can kill your budget and your savings in a hurry, and it’s why you get insurance in the first place.
- Sump Pump Life Expectancy and Maintenance
- The plumber who replaced my sump pump told me that generally speaking, a sump pump will last 4-5 years. It may last longer if your sump water is relatively clean and clear and/or you don’t get a lot of water. It may not last that long if the sump water is dirty or the pump has to run a lot. If your pump is more than 5 years old, you should probably go buy a new one and have it ready just in case… or just replace it now and keep the old one as an emergency spare. Some people keep a replacement on hand at all times just to be safe. Considering that new pumps cost $75-150 and are not too hard to install, that may not be a bad investment.
- It is a good idea to check the operation of your sump pump twice a year. An easy way to do this is to dump a few buckets of water into the sump and verify that the pump kicks on and carries the water away.
- Extra Protection: The Battery Backup
- Earlier I mentioned the need to make sure you have the necessary insurance coverage. Ideally, you’d like to make sure you never have to file a claim. There are sump pumps on the market with a battery backup. If you’re in an area where the power often goes out during a storm, this might be a good investment. You can also consider the emergency pumps they sell, which run on water pressure. To use one of these, you plug in a garden hose and turn it on full blast. The movement of the water through the pump mechanism activates the pump to remove water from your sump. There are even “backup pumps” you can install with the existing sump pump. These backups kick on if the original pump fails. While these backup and battery-powered pumps are not necessarily cheap ($250 and up is not uncommon) they are far cheaper than the expense of new carpeting and basement water cleanup. And they may keep you from having to file an insurance claim, which will help you to keep your rates low and avoid having your policy canceled.
- Cleaning out the Sump
- The plumber who installed my replacement pump told me that the bottom of a sump pit will fill with mud, gravel, and other debris over time. You need to scoop this crap out and get rid of it every so often. (Just how often will depend on your circumstances, but checking it every 6 months is a good idea.) In the best case, this build-up reduces the volume of water the sump can hold at any one time (increasing the likelihood of a flood). In a worst case, it reduces the life of the pump and can clog it up, resulting in the pump failing prematurely (and increasing the likelihood of a more serious flood). It is also a good idea for your pump to be sitting on a flat rock or brick inside the sump so that it is located above the level of the “muck” at the bottom of the sump.
- Don’t Forget the Check Valve
- The check valve, located in the line between your sump pump and the outside, (which prevents water that has been pumped out of the sump from falling back into it when the pump kicks off) should last 7-10 years at most. This is a relatively cheap part and if it was installed right initially, is probably easy to reinstall too. If yours is very old or you’re not sure how old it is, you might want to consider replacing that, too. Otherwise, your pump could end up running constantly, since whenever it stops pumping the check valve will let much of that water fall back into the pit – where it again needs to be pumped out. Your pump will last a lot longer if this valve is actually working properly. If it’s not, the pump will die that much sooner.
- Install an Early Warning System
- You can buy a simple water level alarm for $9.95 from Lowe’s. This device can be installed in the sump pit itself, and set to warn you if the water level in the pit exceeds a certain amount. You might want to buy one of these to install in your sump and on your hot water heater, to warn you if the water level in the area is getting too high.
- Getting the Water Away from the House
- All of this covers you if your sump pump or check valve has a problem, but that’s not the full story. When your pump kicks in and sends that water out of the basement, it has to go somewhere. In most residential neighborhoods, it goes up out of the basement and into the same pipe that carries water from your gutters out to the curb in front of your house. If that pipe gets blocked (with leaves, fine gravel from your roofing, etc.), the water from the sump can’t make it out to the gutters. Most likely, it’ll get pumped out the bottom of the gutter and into your yard. In the best case, this means that the water will flood your yard and maybe kill the grass. In a worse case, it’ll rot the wood of your house/deck near the awning (which it was going to do in our case). In a really worst case, it will seep back down into your basement and back into the sump, where it gets pumped back out again, and so on. This will also kill your pump because the pump will have to pump, re-pump, re-re-pump, etc., the same water out of the basement. To guard against this little problem, make a habit of periodically checking the little “exit port” in the curb in front of your house to make sure that the pump is able to get the water out to the street. If you know the pump is running and all you see is a “trickle” coming out there, you probably have a problem. If you see a decent amount of pressure flowing out, you’re probably OK. If in doubt, it can’t hurt to have a plumber come out and “snake” the pipe for you. The $100-150 you spend for that service could save you hundreds or thousands later.
- Another Source of Basement Flooding – The Hot Water Heater
- Along the same lines, my research indicates that a hot water heater will last 10-15 years typically. The “experts” say that if your hot water heater is more than 7 years old, you should be shopping for a new one now. Reason being you’re close to failure time, but not yet at “emergency” status where you could have a leak. This gives you time to price-shop and pick a good one, rather than having to settle for what you can find in an emergency. Also, you will probably be able to pick up a much more efficient one and perhaps save on your water heating bill, which can be as much as 14% of your overall utility costs. You might also want to think about putting one of those water level alarms on or near the water heater to warn you if it develops a leak.
- Hope this helps some of you avoid the massive expense we had to deal in 2004 and shortly after moving into a new house in 2005…
City water-powered backup sump pump:
http://www.thisoldhouse.com/toh/video/0,,20260244,00.html (this video is better than most)
City water-powered and battery-powered backup systems compared: