overflow pvc pipe lost siphon

yo, I made an overflow pipe. It lost siphon when power cut off. I do not know how to overcome it. In my design there is no inner airline installed.

Attached is my design. Please help.

Just fill up with water manually and place it back to the tank and it will siphon again .....

bro, my only concern is power failure. As the water in the sump will be suck dry by the return pump if the siphon lost. Need help here.

Attached is my modified version. Please help to see if this is workable. Thanks.

I would believe in the event of a power failure, the amount of water sipon to the below sump is determined by the level of the overflow input pipe.

The lower the input overflow pipe in the main tank, the more water it will sipon down than a one which is 1" below the water level.

nos.... it will stop siphon when the pump stop and when the water fell below the outer 2" pipe. Now my problem is how to get it restart.

If I am not wrong after topping up the water above the inlet overflow pipe with the valve closed, then you open the valve, it should sipon again.

you are right! but it may not necessary always work everytime.

the 'inlet' may be still contain 'air' which will 'open' the siphon.
imo, make a small hole (1st bend) and connect an airlifter to pump water it will push the air out.. when it is filled... just release the valve...it should wa-la..

Yep ... should have thought of what wlchew has suggested.

Read again this thread: http://www.arofanatics.com/forums/sh...d.php?t=345192
All the answers are there. Look out for your pipe length and height. Good Luck.