How to protect from overflowing sump?

[Sarah1990]

I have been trying to find a way to ensure my sump wont overflow in a power cut or pump failure but cant work it out.
I see a lot of advice to drill a hole in the return pipe just below the water line but I dont have a pipe into the tank just this nozzle?
How can I make this safe from flooding?

 

[SPR1968]

I’ve actually been researching this and you can install a non return valve (the ball version I believe is best for reliability) into the down pipes and you can also get anti siphon caps to fit at the top of the return pipe

There are different ways of doing it but you need one that is reliable and not going to cause issues including maintenance

 

[mfinn]

I have been trying to find a way to ensure my sump wont overflow in a power cut or pump failure but cant work it out.
I see a lot of advice to drill a hole in the return pipe just below the water line but I dont have a pipe into the tank just this nozzle?
How can I make this safe from flooding?

most people figure out how much water is going to back siphon from the tank ( in a power outage) and just leave enough room to handle that amount.

 

[Jonathan Troutt]

I have been trying to find a way to ensure my sump wont overflow in a power cut or pump failure but cant work it out.
I see a lot of advice to drill a hole in the return pipe just below the water line but I dont have a pipe into the tank just this nozzle?
How can I make this safe from flooding?

Check this out . Can you see the water level that is where mine ends up after a power outage..... had me sweating for sure!! Lol

 

[Halal Hotdog]

most people figure out how much water is going to back siphon from the tank ( in a power outage) and just leave enough room to handle that amount.

This is exactly what I do. Ball valves can fail, and if they do you are looking at a real mess. Leaving enough room in your sump to hold the additional water is the easiest and safest way to do it.

 

[W1ngz]

-Leave all the pumps off
-start filling the main tank. Keep filling until the water starts running down the return and overflow
-stop filling when the sump level is about an inch (or whatever level you're comfortable with) from the top of the sump
-Wait to be sure all the water has drained from the pipes and overflow. You might be surprised how much water is hiding in the plumbing.
-Start the pumps and let it run for a half hour to fully stabilize
-Mark the sump water level, and the return chamber water level. That is your maximum safe operating water level.

One-way or check valves are NOT safety devices or flood prevention devices. I use one on my system for the simple reason that it limits the splashing and air bubbles pushed back into the tank when the pump restarts, since the line is mostly full.