sewage pump runs 30+ minute, help!!!

Hi, dear expert,
I bought a 14 year old house six month ago, with a sewage pump in the basement. The pump usually runs for around one minute when we use water in the basement, and then stop with a sound "bang".
But starting from last week, it runs for more than 30 minutes everytime, but seems less frequently. I am not sure what is the desired behaivour. Is there anything wrong? Shall I ask a professional to check it out? Does the pump require regular maintainence?

Also, how long can a pump last? Shall I replace it since it's 14 years old already. If I need to replace it, how much will it cost roughly? Below $500, below $1000, or above $1000?

Thank you in advance! I really need to know these. (my wife is scared, she think stuffs will come out of the toilet...) help!!!!

Raymond

If you are on septic, the rest of the house flushibg O.K.? Could be paper ball under float in tank but most likely you need new pump or pump switch if your handy. Unplug pump and pull the cover and inspect it.

Assuming yr basin is 30gallons, and the pump is between 1/2hp and 3/4 hp, it *should* take about 10 seconds +/- to empty. It should NOT take 30 minutes.

Some things that could be problems (all speculation based on my own experience only):

Shut off valve on discharge line not fully opened. If closed, sewage will have no place to go and you could trip/burn out the pump.

Faulty check valve. I read a lot of posts like yours and the culprit is a bad check valve that won't close. If the valve is mounted vertically, then when the pump empties the basin, it will turn off and the column of water above the valve will fall back onto the valve, shutting it. If the valve is not shutting, the water will fall all the way back down to the basin. However, I doubt this'd cause the pump to keep running; I think the returning column of water wouldn't be high enough to reactivate the pump.

Bad float. If the float is stuck in the on position, the pump will keep cycling. Eventually, the vibration or gravity might unstick the float, which is why it'd stop after many minutes. I'd test this. If your pump piggy backs on the float, then unplug the float and pump. Then fill the basin partially. Then plug in the pump directly to the outlet. If it empties and shuts off properly, the float's the culprit. If yr pump doesn't piggy back, then plug everything in, remove the cover of the basin, fill it manually, and observe how the float rises and whether it falls appropriately after the basin empties.