A sump pump is one of those things in life that you never think about until it stops working. Oftentimes, you won’t know there is something wrong until you’re ankle-deep in water. Sometimes, though, you may get lucky and notice sump pump noise, a telltale sign that trouble is down the road. Keep an ear out for uncommon noises like banging, gurgling and humming, and conduct routine maintenance for years of worry-free use.
Here’s what to do if you hear those uncommon sounds from your sump pump.
Gurgling: This sump pump noise usually indicates that water is flowing back down the pipes after the pumping cycle. A common cause for this is a lack of or a malfunction in your check valve, which opens as water rushes up from the pump and closes when flow lessens. If your model has a check valve, you can find it on the PVC or ABS pipe directly above the sump basin. It is fitted with rubber slide sleeves and held on with radiator clamps, so you can fix it relatively easily by loosening the clamps and replacing the valve. ALWAYS be sure to unplug the pump before making any repairs.
Banging: A banging or thudding noise is usually caused by a rush of water streaming back down the pipe and hitting the closed check valve. If you have a particularly long rise of pipe from the basin, having the check valve installed higher up might lessen the thud. Since this requires cutting into the line, it is a good idea to have a licensed, professional plumber do the job.
These sounds can also be caused by pipes hitting wall joists or other framing structures. A simple way to check for this problem is by grabbing onto the pipe when the pump kicks on, as vibration can rattle the pipes. If this is the problem, securing the pipe with additional clamps should alleviate it.
Humming: This is a common sound when the pump is running, but if the noise is constant, then the system might be running without actually moving any water. A common cause for this is the lack of a relief hole between the pump and the check valve, which will develop an air lock in your system. Drill a 1/16- to 1/8-inch hole into the plastic PVC or ABS pipe at a downward angle, so water shoots out back into the basin between the pump and check valve.
Another cause could be a clog somewhere in the line, most commonly at the pump itself. This can be fixed by removing the sump pump, taking its bottom plate off and clearing away any debris. If the problem persists, call a licensed plumber, as the problem is probably further down the line.
Humming can also be an indication that the pump’s motor has failed, which means you will have to replace the unit.