How do I maintain and test a sump pump?

Wayne, a pump maker, puts the test this way: "Pour a bucket of water into the pit to make sure the pump starts automatically and the water drains quickly once the pump is on. If the pump doesn't start, have it serviced or replaced." Liberty Pumps, another maker, gives the same test on a monthly schedule: "Pour enough water into the sump to activate the pump when not normally in use to verify proper function."

Here is the test step by step:

1. 1Take the pit cover off, if there is one.
2. 2Pour in water slowly until the float rises and the pump starts. A bucket or two is usually enough.
3. 3Watch the water level fall. It should drop steadily and stop when the float drops.
4. 4Listen. The pump should sound smooth, without grinding or rattling.
5. 5Confirm the discharge line is moving water away from the house, and put the cover back on.

You don't need to unplug the pump for this test, and you should not reach into the pit while it is plugged in and running. If something looks wrong and you have to touch anything in the pit, unplug the pump first. Liberty's manual says to "always disconnect pump(s) from power source(s) before handling or making any adjustments."

If the pump will not start, see our guide on why a sump pump won't turn on. If it starts and will not stop, see why a sump pump runs constantly.

Liberty's manual lays out a simple schedule. Wayne's advice is close to it. Together they cover the parts that fail most.

Monthly

• Run the bucket test above. Liberty also says pumps that sit idle in a wet basin must be removed, and that a pump should not be stored in a wet basin.
• If you have a battery backup, check the battery. Zoeller's DC backup instructions say: "It is the owner's responsibility to check the battery and battery connection at least once a month."

Quarterly, or three to four times a year

• Check the pump for corrosion and wear.
• Check that the float moves freely. Liberty says "the float must be able to move freely through its complete travel without any restrictions." Wayne adds that the pump should be inspected three to four times a year "for pump movement or buildup of debris on the switch or float," and repositioned if it has moved.
• Check the check valve. Liberty says to inspect for proper check valve operation. A leaking check valve lets water fall back into the pit and can make the pump cycle, as our guide on why a sump pump runs constantly explains.
• Check that the pit is free of debris. Liberty says to check that it is free from accumulated debris, rocks or other objects that could jam the pump.
• Check the inlet screen. Wayne says to check the screen and clear away any small stones or debris.
• Make sure the pump stands upright. Wayne warns that vibration can make it tilt, and a tilted pump can jam the float so it can't activate the pump.

Every year

• Liberty says to inspect and clean the basin and replace any defective components.

Every two years, for tether-float pumps

• Wayne's manual says: "Replace the tether switch every two (2) years." It calls this maintenance required, to reduce the risk of improper pump operation, switch failure and flooding, and says a lack of proper routine maintenance will void the warranty. That rule is Wayne's for its own tether-float pumps. Check your pump's manual for its schedule.

One more check applies to the power supply. Wayne says the pump should be plugged into a working GFCI outlet with a cord in good shape, and adds: "In damp areas, GFCI breakers may trip, effectively shutting off the sump pump." Press the test and reset buttons on the outlet during your quarterly check. Don't power the pump through an extension cord. Liberty's manual says not to, because extension cords can overload the pump and the cord's supply wires. If the outlet trips again and again, see why a sump pump keeps tripping the GFCI, and if a high-water alarm sounds, see what a sump pump alarm means.

Two small parts get overlooked and cause trouble.

The check valve, which sits on the discharge pipe, stops water from falling back into the pit after each cycle. Wayne says a check valve is required with its pump. Liberty says a gate valve should follow it, so the check valve can be cleaned or the pump removed.

A small hole in the discharge pipe, called a weep hole or air relief hole, lets trapped air escape so the pump does not airlock. Zoeller says it is recommended to drill one "just above the pump's body and below the check valve." Liberty builds an anti-airlock hole into its pumps and says a small spray of water from it is normal while the pump is running. If that hole clogs, clean it. Liberty says that after a clog is removed, "the anti-airlock hole should be cleaned."

If you find a stuck check valve or a clogged hole, it is a reasonable job for a plumber, especially if it means cutting into the discharge pipe.

Zoeller's FAQ gives a straight number: "With proper installation and maintenance, your pump can last on average 7-10 years, although actual lifespan may vary based on usage conditions." That is one manufacturer's average for its own pumps. A pump that runs often, pumps dirty water, or is not maintained can wear out sooner, and a pump that seldom runs may last longer.

Wayne and Liberty give warranty periods instead of lifespans, and warranties are not the same as expected life. Liberty's limited warranty on its wholesale products is three years from the date of purchase, and Wayne's manual says lack of routine maintenance voids its warranty. A pump that has passed the warranty period and has never had its switch replaced deserves a closer look.

Signs a pump is near the end: it makes new noises, it takes longer to empty the pit, it cycles more often, or it fails the bucket test. Zoeller notes that unusual noises can indicate an obstructed impeller or worn bearings. It says to turn the pump off and unplug it before checking.

Don't wait for a failure if the pump is old and the room below it is finished. If you have a lower level that is valuable to protect, a backup helps. Our page on whether you need a battery backup for a sump pump explains how they work.

### Does an Arizona home need this at all?

Only if it has a sump pump. Most Valley homes do not. Our guide on whether an Arizona home needs a sump pump explains when one makes sense. If you have one, and it has been years since anyone looked at it, run the bucket test now.

Want a second set of eyes on your pump? HQ Plumbing and Air can inspect it, replace the switch or check valve, or install a new pump. We are licensed and insured, and you get the price up front. For a sewage pump's switch, see how to replace a sewage ejector pump float switch.