I am looking at a house that has a grinder pump to pump sewage uphill. I need to know how often they fail with the result of raw sewage backing up to the basement in the house. The basement is finished.

The failure rate depends on how often it is used and the quality of the unit. In most cases 5 -8 years and I'd swap it out before it fails if you reach 8 years. Is the basement bathroom the only thing on this pump? If so, when it fails you will know almost immediately and you should be able to prevent flooding of sewer water and sewage in the basement.

Most of these systems have alarms so that you will know if there is a failure...some even have backup grinder pumps (depending on code requirements), so I don't think there is much to worry about in terms of sewage backing up. The bigger concern is probably going to be periodic replacement/repair costs, for sure!

Mark

Thank you so much for taking the time to answer my problem! Bless you both. We decided to go to the County Wastewater office and request information on these. It was the right thing to do. We found out: Once the homeowner in this county purchases the grinder pump, and hooks it up the municipal sewer, the system is maintained by the county including replacement costs for a new unit which last an average of 14 years. (this one is 3 years old) There are two backflow valves in place to prevent sewage backflow. If the power goes out, they come out and pump the tank twice a day. We felt much better after talking to the county guys. They gave a 24 hour emergency number to call if the alarm goes off (80 decibels) They give you a list of donts: If the power goes out don't run water. If it stays out 2 hours or more they will come out and pump you out so you can take a shower or whatever. There is a list of stuff you must not do: flush tampons, butt wipes, paint, grease, sox, you get the idea. NO DRAINO!
It turns out on the larger lots in our city that used to have septic tanks, the county wants to put them on the grinder systems to make the EPA happy. That's why they maintain them after the original cost to the homeowner of $17,000 to hook up to municipal sewers.
Wow we heard more about sewers today than I ever want to hear. I feel better about this possible home now. Thank you so Much!

I believe the grinder will be in a pit, outside your house, not inside. The grinder will push the effluent to a force main or a gravity drain..