My brothers house is at the bottom of the hill. They put in three sump pumps. One runs pretty much all the time. One side of his yard is constantly wet. He needs to run it out farther or make a dry rock bed there or something because he can hardly mow over there.
I can't imagine what his electric bill is. Running a little pump 24/7 has to cost him. Especially when he has two others.
I would avoid it if I could.
Do you have a link to the listing? Should be easy to spot if they have photos of the outside of the house. Personally, I wouldn't buy a house that
didn't have a sump. You're right up my alley, I've been playing this game the last couple summers with managing storm water flow.
My sump runs at least once a minute if it's been rainy. We haven't had rain for close to two weeks and my curb still isn't dry, that's how much it runs. Some places just have a higher water table than others. Ours is very high in my neighborhood. If you have one that runs a lot, you have to discharge it off your property or you'll be the proud owner of a swamp.
But they don't only run when it's raining or the sprinklers are on, especially at the bottom of a hill. As for noise, the check valve is the noisy part. They sell quiet ones, if you have a cheap one you will hear it clunk shut. Some people like a quiet one on their main pump and a loud one on their backup, that way they know if they hear it clunking they need to replace their main pump.
I do hear my pump if I'm listening for it, I can hear it hum. I could soundproof the closet it's in if I wanted, but I'm the only one who notices it and I like knowing when it runs.
The only issues I've had with water in the basement were because of bad slope, a window well drain that was installed too high, and chipmunk damage. Never the pump. And those were trickles of water, not a flood. Once I moved downspouts and fixed that drain and the soil slope, the basement has been dry.
It's easy to see if you know what you're looking for. Walk the perimeter of the house and with the knowledge that water goes downhill, and ask yourself where it's going to flow when you get a heavy rain. Make sure the downspouts extend at least 6 ft away and wherever they let out has a downhill run away from the house. It's cheap to get a load of dirt brought in and build up a little lip around the perimeter of the house. That would be an easy concession to get from the seller to either make them do it or give you money to have it done if the spouts need to be moved.
If it's a finished basement, I doubt they have water problems or you'd smell it. One flood will mold everything. Get into the corners and the closets down there and really sniff around.
As mentioned above, get a two pump system with a watchdog unit that will alarm when the backup is activated. I just replaced my backup battery.
I'm also just about done with the replacement of the discharge line that runs around 90 feet from the back of the house down to the curb. My advice to everyone is to NEVER use the perforated 4" corrugated drain pipe. Those slits let roots in despite what they tell you about using rock and wrapping the pipe. It took about 20 years, but it blocked off totally with roots and had to be replaced.