Shower sump pump size

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BillyK

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My new to me boat needs a new shower sump bilge pump. The one in there is a rule 800 gph. It seems like a lot. If I recall in my other boat it was a 500 gph. Is bigger better, or will it cause it to burn out faster? What is the correct size if any for a shower sump pump.

Thanks,

Billy K.
 
Smaller will be fine, maybe even better as less water will back flow, especially if you can switch to a smaller hose
 
The 800 and 500 use the same size hose as I recall. While I'm not a big fan of check valves, if you have a back flow issue you could install one at or near the pump. Just make sure the pump is screened off from pumping hair or crud from the box. If the box holds a fair amount of water and it tends to get stale you can put a pool chlorine tab in the box to keep the box from getting stinky.
 
Thanks fellas, I'm going to go with the 500 gph. I don't know about back flow yet, but I'll take your advice.

Billy K.
 
Attwood offers a shower sump that has a built in check valve on the box. The sump seems to built of heavier gauge plastic and has a snap on lid (versus screws). It also has an easier to clean screen. I am switch my Rule shower sump to the Atwood.
 
Attwood offers a shower sump that has a built in check valve on the box. The sump seems to built of heavier gauge plastic and has a snap on lid (versus screws). It also has an easier to clean screen. I am switch my Rule shower sump to the Atwood.
 
Always raise the discharge hose higher than the thru-hull fitting if you can as soon as you can. That will reduce the back flow.
 
+1 on the Chlorine or Bromine tablet in the sump. I found the Attwood sump was prone to failure. Once I switched to the Rule sump assembly I haven't had a problem in 4 years. I routinely clean the box out, which includes removing the pump from it's holder and cleaning it.
Cleaning the shower sump is on my monthly maintenance list.
However to the original question I don't see where having either size pump would be cause for premature failure. I use the 500gph Rule.
Bill
 
quote:
Originally posted by JimPend

Always raise the discharge hose higher than the thru-hull fitting if you can as soon as you can. That will reduce the back flow.

Click to expand...
I like to hear the reason why.

Assumming the pump is below the water line, here are my thoughts. In order to raise the hose, more hose is required. The more hose filled with water, the greater the amount that will flow back towards the pump. When the pump turns off then gravity takes over. The end of the hose at the pump is lower and that's the end the water will drain back to.
 
I would think that if you have a longer hose run going down after the high point, the water in tht section of the discharge hose will siphon most of the water in the section between the pump and the high point.

Also, by shortening the distance between the pump and the high point, you have less water that will drain back. Let say your sump is on centerline, if you run the hose to a high point on the hull, you re going to have 6 to 7' of hose to get to a hull side, then 2 or 3 more going up. That s 8 to 10' of hose full of water.. On the hot hand if you go straight up ours only going to have the 2 or 3' going up, the remaining 6 to 8' will be downhill and self draining
 
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