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Last Updated on October 1, 2026 by Muhammad Toqeer
Monthly, and the bucket is one of seven checks. Liberty publishes a tiered maintenance schedule — monthly, quarterly, annually — and pouring water in is the whole of the monthly item.
The four quarterly checks are the ones nobody repeats, and one of them is the thing the bucket test physically cannot see: whether the check valve holds when the pump stops.
You will need: a bucket, five minutes, and somewhere to stand. No tools.
What the schedule actually says
Monthly:
“Pour enough water into the sump to activate the pump when not normally in use to verify proper function.”
“Pumps that are idle in a wet basin must be removed — do not store pump in wet basin.”
Quarterly:
“Check pump for corrosion and wear.”
“Check for free and unobstructed float switch operation and float switch condition. The float must be able to move freely through its complete travel without any restrictions.”
“Inspect for proper check valve operation.”
“Check that the pit is free from accumulated debris, rocks or other objects that may potentially jam the pump.”
Annually:
“Inspect and clean basin. Replace any defective components.”
Seven checks across three intervals. The internet publishes one of them, without the interval.
The monthly test, done properly
1. Pour, and listen
Use a bucket, not a trickle from a hose. The point is to raise the level past the float’s on point reasonably quickly, the way rain would.
Listen for the start. A pump that starts promptly and sounds steady has passed the first half.
2. Watch the level fall
It should drop decisively, not creep. A pump that runs but moves the level slowly is telling you something about the discharge rather than the motor.
3. Go and look at the far end
This is the step the bucket test skips, and it costs a walk.
Water has to arrive where the discharge terminates. A pump can run, sound right, and empty the pit into a line that is blocked, frozen or disconnected under the ground — and the pit will still drain while the pipe fills.
4. Then stand still and watch the level
This is the check valve test, and it is free.
After the pump stops, the level should stay down. If it creeps back up with nothing arriving, water is returning down the discharge pipe — which is the recirculation loop that makes a pump run with no rain, and the manufacturer lists checking the valve as a quarterly item for exactly this reason.
A bucket test passes happily while this is happening. That is why it is not the whole test.
5. If it is a standby pump, take it out
The instruction that surprises everyone, and it is unambiguous:
“Pumps that are idle in a wet basin must be removed — do not store pump in wet basin.”
A pump sitting unused in standing water should not be left there. It runs against the instinct to leave everything in place and ready, and it is in the monthly list rather than a footnote.
The quarterly checks, which take a few minutes more
Corrosion and wear. A visual check. You are looking at the housing and the hardware, not inside anything.
The float, through its whole travel. The maker’s wording is specific: “must be able to move freely through its complete travel without any restrictions.” With the power off, move it by hand from the bottom of its arc to the top and feel for anywhere it catches on the pipe, the cord or the basin wall.
The check valve. Covered by step 4 above — and if you want to inspect it rather than infer it, that is a plumbing job rather than a look.
The pit, for debris and rocks. The manual’s words are “debris, rocks or other objects that may potentially jam the pump” — and rocks are named specifically, because people put them under pumps. One manufacturer sells a moulded stand whose published purpose is to replace exactly that practice.
Before you take anything apart
There is a clause worth reading first:
“No repair work shall be carried out during the warranty period without prior factory approval. To do so may void the warranty.”
“Just have a look inside” is advice the internet gives freely. On a pump still in warranty it is a decision with a consequence, not a diagnostic step.
And if the pump fails any of this, the maker’s own list of causes for a pump that will not start puts the motor third of nine — most of what goes wrong is not the pump.
When this needs a pro
Anything inside the pump, for the warranty reason above and because they are sealed units.
Anything electrical. Testing with water in a pit and power on is the combination to stay away from — do the float check with the power off.
Opening or resealing the pit. The cover should be gas-tight and fastened down, so the annual basin clean is more involved than it sounds.
Replacing a check valve, which means cutting into the line that protects the basement.
What you can do yourself: all five monthly steps and three of the four quarterly ones. The only one that needs anybody else is inspecting the valve properly — and watching the level after shutoff tells you whether that inspection is urgent.
And if the test says the pump is no longer keeping up, compare replacements on flow at your actual lift rather than on horsepower.
FAQ
How often should you test a sump pump?
Monthly, according to the manufacturer’s published schedule. That is the pour-water-in test. There are four further checks specified quarterly and one annually, which almost nobody repeats.
How do you test a sump pump with a bucket?
Pour enough water in to raise the level past the float’s on point, listen for the pump to start, and watch the level fall. Then add the two steps the bucket test leaves out: check water arrives at the far end of the discharge, and watch whether the level creeps back up afterwards.
What does a bucket test not tell you?
Three things: whether the discharge is clear all the way to its outlet, whether the check valve holds when the pump stops, and whether the pit is free of debris that could jam the pump. All three are on the manufacturer’s quarterly list.
Should I leave a spare sump pump sitting in the pit?
No. The manual is explicit that pumps idle in a wet basin must be removed and that a pump should not be stored in a wet basin. It is listed as a monthly item rather than a footnote.
How do I check a sump pump check valve?
The free version is to watch the water level after the pump shuts off. If it rises again with nothing flowing in, water is coming back down the discharge. Inspecting the valve itself means cutting into the line, which is a plumbing job.
Can testing a sump pump void the warranty?
Testing it, no. Opening it might — the manual states that no repair work should be carried out during the warranty period without prior factory approval, and that doing so may void the warranty.
