what is 'normal' sump pump time on/ time off cycle?
#1
Member
Thread Starter
what is 'normal' sump pump time on/ time off cycle?
Hi all!
So, we had a pretty major storm last night. I noticed the sump pump would cycle on.. run for 5 seconds... then shut off. It took about 20 seconds for the pit to fill enough to trigger another run.
Is this optimal timing? Something is telling me it should let the pit fill more, then run a little longer, taking more time to rest in between...
Any best practice out there for this? I am assuming it will just be an exercise in adjusting the float? Its a new pump, put in to service last year.
So, we had a pretty major storm last night. I noticed the sump pump would cycle on.. run for 5 seconds... then shut off. It took about 20 seconds for the pit to fill enough to trigger another run.
Is this optimal timing? Something is telling me it should let the pit fill more, then run a little longer, taking more time to rest in between...
Any best practice out there for this? I am assuming it will just be an exercise in adjusting the float? Its a new pump, put in to service last year.
#2
Member
Mostly it is a function of sump size and pump size. Most submersible pumps do not have adjustable floats. On some you can adjust the vertical position, but that just changes the static level in the sump; the difference in pump on to pump off levels will stay the same.
I have a 24" diameter sump and 1/3 HP pump and it runs about 30 seconds. 5 seconds is pretty short, but nothing easy you can do about it, short of enlarging (diameter) of sump or changing to a smaller pump, and I don't see any point in doing either.
I have a 24" diameter sump and 1/3 HP pump and it runs about 30 seconds. 5 seconds is pretty short, but nothing easy you can do about it, short of enlarging (diameter) of sump or changing to a smaller pump, and I don't see any point in doing either.
#3
Group Moderator
For many motors starting is the hardest part of it's life so you try to minimize the number of on/off cycles it makes. As Carbide Tipped mentioned it's a trade off. I think the biggest trade off is the size of the pit and to make it larger you often have to dig deeper or give up floor space in your basement. Something that most don't want to do.
The bigger issue is that your sump is refilling in 20 seconds. Do you have a backup? How high will the water get if the pump dies, switch fails or the power goes out?
The bigger issue is that your sump is refilling in 20 seconds. Do you have a backup? How high will the water get if the pump dies, switch fails or the power goes out?
#4
We are assuming here that you have a submersible. If you have an upright you can adjust the float to almost overflow. That will reduce the cycle time. Do you have a check valve to prevent back flow?
PD's suggestion of a back up is excellent advice.
PD's suggestion of a back up is excellent advice.
#5
Member
Thread Starter
pump specs
Its this pump
Zoeller 57-0001 M57 Basement High Capacity Sump Pump
.3 hp. I have never thought to measure sump diameter.
This was one of THE major rain events we've had in the last two years of me owning this home. First thing I did was put a water powered backup sump in, when we moved in.
I assumed I could adjust this float (plumber installed this pump when putting in backup)
Part of the issue, I think, is after the sump cuts off, water (I am guessing whatever is in the pipe between check valve and pump? Sounds like more than that) comes back into the pit
Zoeller 57-0001 M57 Basement High Capacity Sump Pump
.3 hp. I have never thought to measure sump diameter.
This was one of THE major rain events we've had in the last two years of me owning this home. First thing I did was put a water powered backup sump in, when we moved in.
I assumed I could adjust this float (plumber installed this pump when putting in backup)
Part of the issue, I think, is after the sump cuts off, water (I am guessing whatever is in the pipe between check valve and pump? Sounds like more than that) comes back into the pit

#6
It's hard to see in the picture but if a lot of water is going back in the pit then you don't have a check valve. But I doubt that is the case. The plumber who put in the sump pump should have put a check valve at the pump discharge.
#7
Member
Check valve could be jammed as well by debris.
If it was a serious enough rain event and enough water drains towards the house having it fill up in 20 seconds isn't necessarily that strange. I have a 130 gallon sump which is relatively large and when it down pours it can fill up in less than 30 seconds as well.
Have you checked how it works during a more normal rain to see if it does the same thing?
If it was a serious enough rain event and enough water drains towards the house having it fill up in 20 seconds isn't necessarily that strange. I have a 130 gallon sump which is relatively large and when it down pours it can fill up in less than 30 seconds as well.
Have you checked how it works during a more normal rain to see if it does the same thing?
#9
The pump should start before the large drain pipe ends emptying into the pit are completely submerged. The pump should keep going until the pump is nearly empty.
It is okay for the water level to sit for long periods of time a little below the pump turn on level.
I suggest that the pit (sump) have at least 3 cubic feet of volume below the drain pipe ends, not filled with rocks or gravel. This usually means custom building the pit using bricks or concrete instead of using a standard plastic liner.
If water laps up against the house, that needs to be fixed. Regrade the land if needed.
It is okay for the water level to sit for long periods of time a little below the pump turn on level.
I suggest that the pit (sump) have at least 3 cubic feet of volume below the drain pipe ends, not filled with rocks or gravel. This usually means custom building the pit using bricks or concrete instead of using a standard plastic liner.
If water laps up against the house, that needs to be fixed. Regrade the land if needed.
#10
If you have a float that rises on a stem there is only a very small adjustment possible with that type of level control.
The type that has a float on the end of a flexible cord will often give you a much greater adjustment than the other type.
You do need to be more careful with the last type because they need more space in the sump to make sure the float does not hang up on anything.
The type that has a float on the end of a flexible cord will often give you a much greater adjustment than the other type.
You do need to be more careful with the last type because they need more space in the sump to make sure the float does not hang up on anything.
#11
Member
Looks like two check valves to me, right next to each other about a foot above the pit. Your plumber used the good ones with unions, so you can just unscrew the unions and check to make sure they aren't jammed up.
That's a nice professional installation by the way.
That's a nice professional installation by the way.
#13
Member
Thread Starter
thanks for all the replies
Yeah, I ended up hiring a really pricey plumber to hook up the water powered backup pump when my 'contractor buddy' bailed on me. Had them swap the primary at the same time (I bought the pumps on my own) Cost a fortune, but they did a good job. Maybe I'll check those check valves. I was concerned the pump I was replacing MIGHT have been overpowered for my pit, but I just went like-for-like
Maybe thats the issue
Yeah, I ended up hiring a really pricey plumber to hook up the water powered backup pump when my 'contractor buddy' bailed on me. Had them swap the primary at the same time (I bought the pumps on my own) Cost a fortune, but they did a good job. Maybe I'll check those check valves. I was concerned the pump I was replacing MIGHT have been overpowered for my pit, but I just went like-for-like
Maybe thats the issue