Backup Sump-Pump Problem

All,

When testing my battery powered backup sump pump a few weeks ago, I noticed it wasn't pumping any water (it was making noise like it was trying to). I disconnected and then re-connected the pipe and it seemed to start working again. Now a few weeks later, I checked it and had the same problem, and again it was resolved by disconnecting and re-connecting the pipe.

The battery is only a couple years old and the water levels look fine.

Any idea what could be going on?

Thanks, Dan

Reply to
dan.hoffard
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What is battery voltage

Reply to
ransley

12V
Reply to
dan.hoffard

12v is 25% charged or 75% dead.
Reply to
ransley

Sorry.. I thought you meant what kind of battery.. I'm not sure of the actual voltage.. My multimeter isn't working

Reply to
dan.hoffard

Air lock? Is there a little hole (1/8+ inch diameter and unclogged) in the discharge pipe below the checkvalve?

Reply to
Erma1ina

I looked and didn't see any holes. I should also mention there appears to be two check valves installed in the line.. One right before the connection to the pump and one at the 90 degree turn in the pipe toward the wall. Does the hole need to be above the water line? If so it may not be possible if it has to be below the first check valve.

Reply to
dan.hoffard

I would not trust those chargers without knowing it keeps a proper voltage be testing it, I would think a properly charged battery should last 20 + years. Unless the battery is kept at a minimum of 12.8 it will sulfate and be ruined in a year.

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has all sorts of battery info, that could be the real issue a weak sulfated battery.

Reply to
ransley

Two check valves ??? Where do the two output lines from the main and standby pumps come together, or are they completely separate, pls describe the situation in a little more detail.

Reply to
hrhofmann

separate pipes for the main and backup.

Reply to
dan.hoffard

lead acid batteries have short lives, after a few years their capacity drops a lot.

20 years? you are dreaming:(
Reply to
hallerb

Apparently some pumps have an anti-airlock hole built-in. If you can, check your owner's manual to see if yours does and where it's located. If you don't have that manual available, check around where the main pump housing fits into the base for a vent/relief hole. If you find one, be sure it's not plugged up. From what I've read, that's a problem with the built in anti-airlock vents -- being near the base of the pump, closer to the bottom of the sump pit, they're more likely to be plugged with dirt and debris than if they're higher up in the discharge pipe. But in any case they need to be between the pump discharge and the check valve, though not necessarily above the water, though, again, if not above the water they are more prone to clogging up and also more difficult to check.

My sump pump (Wayne CDU790) does not have a built in anti-airlock vent. The check valve is on the discharge line above the sump pit and the anti-airlock hole is about a foot or so below the top of the sump pit so it sprays onto the sump wall when the pump is running. Even there, it does get a bit of dirt build up over time so I clean it out yearly with a nail.

Here's as good an explanation of the sump pump "air lock" issue as I've found:

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"Envision the sump pump drawing down and sucking air before the pump switch deactivates. Now you have a small pocket of air around the impeller and nothing leading to the bottom side of the check valve.

The impeller does not have the force to move air, only water. That 3/16" [anti-airlock vent] guarantees that water will enter into that chamber where the impeller is so that the pump can force the check valve open. Doesn't matter where that check valve is; those pumps are not designed to move air.......only water.

Even if the check valve was 8 feet up.......that air hole will allow that huge pocket of air to displace quickly enough to engage water to push up to open the check.

It's not rocket science but I've seen too many pump failures that did hundreds of thousands of dollars of damage and I can go right to the pump, take it out of the pit and start it right up like there is nothing wrong with it.

And there isn't; the pump air-locked and had nothing to do with product, had everything to do with workmanship error."

Reply to
Erma1ina

if theres any chance to run a sump overfull gravity drain to daylight, thats idea.

like a home that sits a little high above street level

Reply to
hallerb

Except a weak battery would not pump after burping the line either. I vote for a priming problem.

Reply to
clare

You are kidding, its basicly unused, no discharging just maintenance charge, no vibration as you get in a car that destroys plates. Low voltage kills them in a 6 months. He replaced one after 1.5 years, that simple fact tells me its a charger issue. On solar instalations you get better life than cars, vibration is a factor you have not considered.

Reply to
ransley

I think the problem is your lack of a vent hole, but if you want to check the voltage on a 12 volt battery, connect a car lightbulb across the ternmainal and see if it glows at the proper brightness. Better yet, connect a car horn and see if has the proper noise. (Although a horn in a cement basement might be a bad idea.)

Reply to
mm

A bulb a horn wont tell you didly on a batterys condition, keep it undercharged at 12.25v and it wil be sulfated in 1 year and worthless

Reply to
ransley

I wrote my whole post below and then realized the key was here. I'm not talking about the battery's total condition. If his multimeter were working (and it's not) the meter wouldn't give the full battery condition either. I only gave him a substitute for a voltmeter and I'm only talking about the voltage, and the voltage is a good indicator of whether the charger is functioning. Hey, I just looked to see how the topic came up, and you were the one who asked what is the voltage in the first place. You didn't ask about battery condition in this subthread.

I think those are two alsmost separate things. If the bulb or horn doesn't work it might be because the battery is worthless or because it is discharged.

OTOH, if it's sulfated and worthless it won't light the bulb or blow the horn. If the battery is still good but discharged, the horn will make less than the expected amount of noise, from nothing to a click, to a buzz, to a weak horn sound, depending on how undercharged it is. It takes a pretty high voltage to give a full blast sound.

The horn is better than the lightbulb because when the bulb is almost bright enough or more, it's harder to judge just how bright the bulb is than to judge the sound of the horn. And because the horn draws more current, which matters when the battery isn't charged enough. This comes up most often in cars, where people are told to check if their battery is charged by turning the lights on. Especially in the day time, it's really hard to tell how bright a lightbulb is, and much easier to tell how loud the horn is.

I"m not saying this will tell you how much longer the battery will work, but it will tell you what the voltage is when you do it. It won't give a specific number of volts, but it will still show the voltage.

Reply to
mm

to test the pump try using jumper cables to a vehicle battery. observe proper polarity.

Reply to
hallerb

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