I grew up in a house with an unfinished basement where the floor was wet every single time it rained. It had a failed drain tile system that my parents chose to ignore due to the very high cost of fixing everything. As a result, a dry basement was one of my primary requirements when shopping for a house as an adult. A walkout basement would have been better.
Flash forward to my current basement, I had my primary pump fail at the worst possible time. So when I replaced it, I bought 2 identical pumps. One is a spare with all of the pipes already connected so that it can be dropped in and connected very quickly when the first one fails.
I also installed this device:
https://www.homedepot.com/p/Liberty...Water-Powered-Backup-Sump-Pump-SJ10/317442611
It is a BACKUP pump that uses city water pressure to pump out water in an emergency. Ideally it should never run, unless your primary pump fails. The float switch is set about 8 inches higher than my normal sump pump.
I've had it operate only once in the last 8 years during a very long power outage. It wastes 1 gallon of water to suck out 1 gallon of water, and it works really well. It is also FREAKING LOUD, so you know when your primary pump has failed.
Another failure piece in a sump pump system is the "check valve". Every sump pump has one, and they're a mechanical component that does fail. If your pump cycles pretty quickly after shutting off, your check valve may have failed. If you hear water rushing back down after the pump shuts off, the check valve has failed.
Those are my lessons learned. I live in an area where it is very common to see those flooded basement rescue vans parked in someone's driveway after a large storm has rolled through. Then you see rolls of carpet and carpet pad being hauled out shortly thereafter.
When I re-did the sump pump this time, I found I had 2 check valves. One in the pump, and a separate one above the pump. However, there should only be 1 per pump, so I cut the extra one out and went with what should be there.
I also just installed a natural gas fueled generator. Our electric service is not the most reliable (unless you ask the city utility, where they insist they are the best) so the generator will now back up the battery emergency sump.
Some things I've learned:
1. The battery doesn't get deep cycled very much, so it lasts about 5 years and then it's done. (BTW: This is typical of most batteries these days - the manufacturers know exactly how to make batteries to deliver 340 CCA or whatever for 5 years, and then you're done. It's lean manufacturing - cheaper costs, because they wrung out all the previous margin.)
Solution: Set an alarm in my phone to purchase a new battery at 5 years.
2. The main sump pump (Basement Watchdog) fails after around 5 years. When I last looked in and when it ran, water would spray out the sides. It was still pumping, but once it corrodes that bad, it's only a matter of time until it fails.
Solution: Every year, I pull the cover and watch the sump pump run. If I see water spraying out the side, it's time to replace the system. At 5 years, it's going to be leaking (cast iron corrodes) so I plan to replace it at 5 years. The next replacement will be in 2029 or so.
3. The pit itself has a drain, but the drain can be plugged by leaves and stuff. If that happens on a heavy rain, I can get water high enough to get over the door threshold and flow into the basement.
Solutions:
1. Clean the pit regularly
2. Have the pit drainage improved from one x 1 1/2" drain to add in a 4" x 36" drain trough, with three 1 1/2" drain lines off the bottom. More area, less chance of plugging up.
3. Clean out the drain emitters in the spring and fall.
4. (edited) Added Orbit Flood Sensors to all locations where water can get in, like the door or the water heater or the furnace drain, so I can quickly arrest and address problems. (Before we had the basement pit drain work, this saved me from having water get anywhere near my games - the alarm went off on my watch and phone, and we got down there and got the shop vac and got all the water sucked up before it even reached the carpeting.)