Submergible Water Pumps

[szw21]

Does anyone here know anything about submergible water pumps (for evacuating flooded areas etc). Here is Socal this is not usually an issue but during the rainy season (like now) we get a lot of water in a short space of time. Again this is not an issue as there is good drainage in the neighborhood.

However, I’m partway through remodeling my backyard and there is a trench (for a wall footing which will be filled with concrete) which keeps collecting water. Since we have clay soil the water takes forever to drain and so need to be pumped out. I initially was using a wet/dry vac – which worked but is a lot of work. So a few days ago I headed off to Harborfreight and decoded to chance it on one of their submersible pumps.

Well I got a chance to try out out today and it seems like it is very hard to get it to start pumping water. After a lot of turning it on and off, pulling out of the water and putting it back in some water slowly started rising up out of the tube. Even then I had to wait maybe a couple of minutes and then little by little the water started running down the tube. Finally it began to flow and once it got going it came out in a very fast jet (the box says something like 3600GPH).

I had another hole which I tired to excavate with it and it was the same thing and I finally gave up as I had to leave.

Is there some secret to priming these to get them going. The book makes no mention of such a procedure. I was wondering whether to prefill the discharge hose with water – not sure if that would help.

[Dan R.]

It sounds like the priming of the pump is the issue. Simply back fill the pump to prime it. If you do this through the tube make sure the water gets to the pump (use plenty of water). Make sure no debris gets in the pump, as a small piece could jam the impeller (that is why Tobias' jiggling helps). We used cheap submersibles on our saw pits for years. We would cut slots in a 5 gallon bucket, put window screen on the inside and then place the pump in the bucket and the bucket in the pit. This kept most of the solids away from the pump.

[kevinp]

You should be able to rent a pump desinged for just that at an equipment rental place.

[Tycapili]

Very true use the bucket with holes...always worked for me. One little thing can clog that sucker up real quick. Depending on the size and i would believe your useing something pretty small. I would dig a foot or so down on your trench wrap that pump with filter paper and set it on a brick. And if that float is a problem. I would tie it to the top.

[Tycapili]

Oh, and if its not running on gas... ther should be no need to prime.

[szw21]

Thanks for the replies. I will have to have another go at this as we have had really heavy rain in the last two days and the whole yard is now submerged - not just the trench. I will try priming it as Dan suggested. I don't believe it is an obstruction as I removed the drain pipe fitting and looked inside at the impellor and it seemed okay. Also this pump is a dirty water pump and ccording to the book should be able to pump out solids upto 1" in diameter.

[Matt Lansing]

If it is a true submersible electric pump then the best way to get it primed is to flip it upside down underwater. This will release the air bubbles inside of the pump and allow it to start pushing water. The other way is to pour water down the discharge hose to remove the air in the pump but I have found that flipping the pump upside down and starting it works the best. Or you can lay it on its side and accomplish nearly the same thing.

[Brian_Stone]

Also make sure that you're discharge isn't too high above the pump. Some of those small pumps can't overcome much head.

We use one of these when we clean out our collection pit in the shop. It's a beast.

http://www.sunbeltrentals.com/equipment ... catid=s466

[szw21]

Great tip from Matt. I just pumped out all the water form the yard. The water was not deep enough to insert the pump upside down but I put it in sideways and it immediately primed. I had about 7 – 8” of water but over a wide area so there was a few hundred gallons to be pumped out. It still took about a minute for the pump to reach peak flow (I assume that’s normal).

This is the pump I’m using

http://www.harborfreight.com/cpi/ctaf/d ... mber=94649

[Matt Lansing]

Sweet!

[Tycapili]

One day we were cutting for a foundation and ran into a 12 inch storm line that had a huge crack in it and was seeping water into are cut. I went to the rental shop for the biggest pump they had. This sucker had a three inch hose and was over 100 pounds. I poured some water in the top and had gallons of dirty water shoot up and hit me square in the head. I backed away soaked in wet and to my amusement the water was over 50 feet high....lol learned my lesson you could say about priming..