I thought I understood the concept of these, but I guess I'm doing something wrong. My box has two U tubes. When I suck the air out of the tubes, it works for a little bit, but within literally 30-60 seconds air bubbles (maybe from water entering the first overflow box?) seem to enter the top of the U tube, and the tube slowly fills with air and loses siphon. I tried leaving the air tube in the top of the tube and I also tried removing the tube. Same results either way. Anyone have any idea what I'm doing wrong?
HOB overflow box, what am I doing wrong?
- Thread starter boojumsnark25
- Start date
How much flow do you have going through them? If you're able to get the siphon started, but air is accumulating that quickly, it sounds like there's not enough flow passing through the u-tubes to keep the tiny bubbles moving out the other side.
the pump I'm using is a Rio 3100, which is rated at 690gph for the height it's at. The water is going through two 1" bulkheads.
Is your return line hard plumbed or flex tubing? How many elbows / Ts? What is the diameter of each u-tube?
Have you tried running the overflow box with just one of the u-tubes? (just as a test) 600 - 700 gph is at the top of the range for a single 1" diameter u-tube (600 gph being ok, 700 gph potentially pushing it too much). 690 gph might not be enough to maintain the siphon in both tubes, especially if the u-tubes are 1.25". If you test it with just one of the u-tubes, be mindful that if the single u-tube cannot drain the volume being pumped to the display, the water level in the display will start to rise above normal. So, keep a close eye and be prepared to turn the pump off quickly if needed.
Have you tried running the overflow box with just one of the u-tubes? (just as a test) 600 - 700 gph is at the top of the range for a single 1" diameter u-tube (600 gph being ok, 700 gph potentially pushing it too much). 690 gph might not be enough to maintain the siphon in both tubes, especially if the u-tubes are 1.25". If you test it with just one of the u-tubes, be mindful that if the single u-tube cannot drain the volume being pumped to the display, the water level in the display will start to rise above normal. So, keep a close eye and be prepared to turn the pump off quickly if needed.
Thanks for the reply. It's flex tubed...I'll have to try one u-tube when I get a chance. That's strange, when I looked at the chart for the wet/dry / overflow box combo I bought, it said it had a 800 gph flow rate
Kind of strange, are you sure you have the U-Tubes facing the right direction? One end is longer than the other. The longer end is on the drain side of the box... How is the Water level in the box? You want that level to be just enough to remove the surface scum. If it is too low there will too much of a waterfall in the box causing excess air bubbles. These will get caught up in the siphon tube causing the siphon to break as you mentioned. If your return is gurgling you can install some durso style overflows. It makes it almost silent. Here is where I got instructions to make mine:
http://home.everestkc.net/jrobertson57268/HGB/
Good luck, and as mentioned you might also might want to try using just one of your tubes and adjust your return with a gate valve to get it fined tuned.
Another note is that Rio pump of yours will probably fail within a year or so. Be prepared to replace it if it does. Usually when you turn it off or have a power outage, they will not turn back on especially if they have been run dry for any length of time.
http://home.everestkc.net/jrobertson57268/HGB/
Good luck, and as mentioned you might also might want to try using just one of your tubes and adjust your return with a gate valve to get it fined tuned.
Another note is that Rio pump of yours will probably fail within a year or so. Be prepared to replace it if it does. Usually when you turn it off or have a power outage, they will not turn back on especially if they have been run dry for any length of time.
Well, I got home from work this morning (3rd shift), took out one u-tube, started the siphon in the other one, and although its a little noisy, it works like a dream! Thanks for the help!
I drilled a hole in the return line right below the water level...that will break the siphon in the event of a power outage, correct? And, in case of the overflow losing siphon, I just need to make sure that the tank can hold the water in the sump, correct?
And one more question...if I monitor the u-tube twice a week for air bubbles collecting, will that be enough, or should I be checking more often? It's kind of in the back and hard to see unless I'm on a step stool
I drilled a hole in the return line right below the water level...that will break the siphon in the event of a power outage, correct? And, in case of the overflow losing siphon, I just need to make sure that the tank can hold the water in the sump, correct?
And one more question...if I monitor the u-tube twice a week for air bubbles collecting, will that be enough, or should I be checking more often? It's kind of in the back and hard to see unless I'm on a step stool
One other problem you will encounter unless you drill your U tube and put on something like a Tom's Aqualifter, is that when a power outtage happens and then power is restored, your pump turns back on and will start to fill your tank back up.. without an aqualifter on the U Tube the overflow box can't create the syphon again on most, and then your tank just overflows onto the floor. (bad experience). Unless you have an overflow box that doesn't break syphon.. but that doesn't sound like the case.
all HOB overflows, if designed right, should start up pretty much all the time during a power outage.
The thing I am wondering and is puzzling me though, is if you drilled the tank for a return, why didn't you for a siphon too?
The thing I am wondering and is puzzling me though, is if you drilled the tank for a return, why didn't you for a siphon too?
With my overflow, siphon is never lost.
My tank is not drilled; the return is an output on the end of vinyl tubing
My tank is not drilled; the return is an output on the end of vinyl tubing