Residential Lift pump runs continuously....

[pancho400cid]

Figures.... Holiday weekend and this morning I hear a weird rumbling in our back bathroom. My suspicions were confirmed when I went out to the doghouse over the lift pump behind the house.

We have a lift pump due to the distance from our house to the city sewer/drain pipe. There is not enough "fall" so the pump is required. It was that way when we bought the house. The pump was running continuously - which it is not supposed to do.

I "think" the pump is controlled by a pressure switch that trips on when the liquid level in the sump gets high enough. If I've got it straight, the pump then runs, drains the sump which trips off the PS, and the pump stops.

I am guessing that switch is the culprit?

Would running continuously for hours with essentially no flow damage the pump?

Thanks!

 

[Fixin'Stuff]

Definitely sounds like a problem with the switch. However, you need to determine what kind of switch you have. Usually in sewage applications there will be a float switch like this one: https://www.plumbingsupply.com/alarm.html Check to see if the switch tether corroded away. I've had that happen in a septic system and it caused the pump to run all the time. If that's the only problem, then the fix isn't too horrible. Pull the pump and riser assembly (some really good, throw-away rubber gloves are a godsend here ) and connect the cord to the riser properly and reinstall.

 

[pancho400cid]

Thanks. Mine does have the piggy-back plug at least.

 

[Bondo]

We have a lift pump due to the distance from our house to the city sewer/drain pipe.

Ayuh,.... Is it Yer pump, or the city's,..??

When mine goes to 'ell, I just call the sewer/ water district, 'n they come fix it, it's theirs not mine,....

 

[pancho400cid]

It's mine. The house was originally built in 1955. There was an addition in the late 90's so the house now looks U shaped from above (was L shaped). The new part didn't have enough fall so the contractor added the pump.

I must say it has been surprisingly trouble-free..... until now.

 

[Jess]

Its likely a float switch set up. On mine fitted to the septic pump tank, it comes on when the level in the pump tank raises the float. Mine is clear water, having already been through the two compartments in the septic tank. In you application, its likely either stuck in the 'on' position or failed. Since you will be pumping solid and other things that shouldn't go in the toilet, it could be trash in the tank that has built up. Open the pump chamber and use a stick with a hook to lift and lower the float switch. I would also suggest gloves and be prepared for an unpleasant cleaning job... Once you have a look, its pretty easy to see the problem and if you have to have a family discussion on what is ok to put into the toilet. In a septic system, that's anything you have already eaten and the supplied toilet paper. Have fun!

 

[reader2580]

I burned out a sump pump with a failed switch that ran continuously so a lift pump would probably burn out too. I dread the day the lift pump in my septic system fails. It will probably be middle of winter.

 

[FullRaceMerc]

It's better that it broke in the on position than off. Much more pleasant to deal with an empty basin than an overflowing one.

As said above, it does sound like a stuck float. Jammed in place by junk, corroded slides, contacts not disconnecting. Might be a tethered float that came unhooked. Who knows without a look? If you need to, unplug it, then plug it in after every few flushes until you have a good time to do the work.

Important thoughts for ejector pump work:

• It will smell bad. Good ventilation & even a fan might help.
  [*]Keep your mouth closed. It's bad enough to get splashed in the face if something goes wrong.
  [*]Empty your shirt pockets before beginning.
  [*]Rubber gloves & old clothes that you can throw away are good just in case.
  [*]If a piggyback switch fails, plug the pump in directly to pump it down so you can do your work.
  [*]If it runs, you can hose it off & pump it out before diving in.
  [*]Most pumps are plumbed so you can disconnect one discharge connection & remove the pump entirely. Probably not needed for switch work, but sometimes it helps. Be aware that an anti-backflow valve undone at the wrong location will allow everything previously pumped uphill to flow back downhill.​

 

[pancho400cid]

Hey guys -

Some great input. Much appreciated. I un-plugged it for now. I'll tear into it tomorrow.

Another angle to the problem:
Last week we had a big wind storm (50 mph peaks or so). It broke a couple of very large limbs off two pecan trees in the back yard. A friend and I spent most of today cutting/hauling to get rid of the limbs. Later I noticed the feeder wires from the transformer were hanging lower than I remembered. On closer inspection the support wire was separated at a crimp splice near the service cap. I think one of the limbs brushed the service drop wires as it fell. All in all probably lucky there were no fireworks. Called the city. They sent a guy who fixed it. He explained that wire was also the neutral conductor - did not know that. So I'm wondering if loss-of-neutral zapped the switch (high voltage welded the contacts shut etc.) or is it coincidence?

 

[pancho400cid]

Hey guys:

I always thought my poop didn't stink.... WRONG! As said though, I could plug in the pump direct and run it, so flushed clean water through a few times which helped a lot. Not pleasant, but not too bad.

I tore into the lift pump/switch issue. I confirmed the switch was not working right. I bought a replacement piggy-back switch from Home Depot. It felt much heavier than the old one and had a definite "clunk" when you flipped it one way and the other. The old one did not... maybe more proof it was bad. HD had a 10 amp and a 13 amp switch. I grabbed the 13 amp and checked the pump when I got home. The pump draws 12 amps per the nameplate. Hopefully OK there. Put the new switch in and it required some jiggering around to run/stop right but all is well for now.

It's set to let the water fill to about 1" below the top of the pump where the wiring goes in before the pump runs. That's about the level it was at before... guess it's ok..

I suspect I may be back into it sooner rather than later as I suspect that having the pump running for hours with no flow probably cut into it's remaining days some.

Thanks again for the info - it helped a lot!