Eheim 1250 water pump

[meow?]

Hi,

For everybody who use's this pump externally I have a question for you. When there a interuption in power or you simulate one does the pump keep the siphon on the intake of the pump? The reasoning behind this question is that mind doesn't. When I simulate a power interuption and then plug in back in the water goes up and down up and down ( on the intake side). If anybody has any idea's let's hear them. This is driving me up the wall:mad2:

[crumbletop]

I'm not quite sure what you are asking. If it is hooked up to a closed loop, then there should be no backflow and no siphon break is necessary. If it is used as a return pump, _all_ pumps that I know of allow water back through the pump into the sump. This is where "breaking the siphon" comes in. When you plumb your system either drill a small hole in the loclines near the surface of the water, or position the outlet of the loclines such that the water volume that flows back to the sump, doesn't overwhelm the capacity of the sump. An alternative is to install a flap valve in the return line. These require cleaning and IMO should not be trusted to absolutely stop all flow back to the sump. So whether you use a flap valve or not, you need to make sure you have enough reserve capacity in the sump to accomodate all the backflow you will get through your return lines.

Jack

[sjm817]

Is the intake up and over the sump? If so, you cant do that. Submersible pumps are not self priming.

[Ti]

I think he has the pump above the water line

[meow?]

crumbletop,sjm817 and Ti

First off thanks for the help and suggestions. Secondly I figured out the problem. This was plumbed below a 5 gal bucket externally as thats all the room that I had for a sump. I had the notion that using US standard pvc with metric fitting could work boy was I wrong in terms with this little pump.
So anyways I switched it out for Eheim tubing all the way around and now it works like a champ. It doesn't lose it's siphon on the intake anymore I've tested mutible times and it fires right up every time.

[Avast Marine]

With enough teflon like 12 wraps you can get the metric to work with standard. The threads/" are similar if not exactly the same, much closer than the pipe diamaters so it seals just fine.

[d.can82]

My expeirince is that the threaded intake on the 1250 is 1/2" thread while the hose barb that threads into it accepts 3/4 tubing. The outlet is threaded 3/8 as far as I can tell while the barb slips into 1/2". This is all very strange and hard to plumb.