How to cure a short cycling shower sump?

L

Lucky Dog

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I've got one of those rule shower sumps that the water standing in the hose seeps back into the sump every 15 minutes or so. This is more of an annoyance than anything else, but I want to fix it.

I've cleaned out the little joker valve in the discharge of the pump, but it still allows a little water to stream back in. I've considered trying to raise the float switch somehow. Or I was thinking of installing a waterwitch switch in place of the float switch. I can't find a 3/4" backflow preventer.

Any ideas?

David
 
Use a shower sump box that has a larger surface area ;). That way, when the outlet hose back-flushes into the sump box, the volume of the hose will be insufficient to raise the water level enough to re-trigger the pump switch.
 
quote:
Originally posted by Lucky Dog

I've got one of those rule shower sumps that the water standing in the hose seeps back into the sump every 15 minutes or so. This is more of an annoyance than anything else, but I want to fix it.

I've cleaned out the little joker valve in the discharge of the pump, but it still allows a little water to stream back in. I've considered trying to raise the float switch somehow. Or I was thinking of installing a waterwitch switch in place of the float switch. I can't find a 3/4" backflow preventer.
Click to expand...


If by "backflow preventer", you mean a check valve, they are not at all hard to find. They can clog with hair, etc. and not seal so the water will still flow back into the sump.

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Is it ok to use the valve that Kellyg linked to in an air conditioner intake line. Last year I developed a problem where I would lose prime in my air conditioner while running. If I closed the ball valve before taking off I wouldn’t have any problems.

Thanks
Niles
 
All good suggestions, thanks.

I'm going to try out the boatfix check valve. I looked in the catalog, but I did not see it in 3/4", thanks.

No vertical room to loop the hose or to put in a larger box, if they make one. I did find that whale makes a version of the rule sump now.
 
a check valve is the last thing you want to put in a shower sump as sooner or later it will clog up. at best it won't work, at worst it will prevent discharge.

3 thigns to check... first try to keep the hose run as short at possible, going straight overboard, not some lenght along the hull before exiting.

second, a 12" loop above the water line will help and prevent water from coming in from teh outside...

finally, make sure the sump is big enough and make sure the float switch is installed properly: secured, level, etc...

you shoudnt need to resort to a check valve, fix the problem, dont' put a bandaid on it.
 
What if you attached a quarter (weight) or series of coins to the current float switch to delay the activation?
 
quote:
Originally posted by KiDa

What if you attached a quarter (weight) or series of coins to the current float switch to delay the activation?

Click to expand...


...or a washer or two under the mounting pads of the float to raise the 'cut-in' level....
 
The "cures" above are interesting but likely ineffective. The problem is "hysteresis" and in this case there is too little of it.

Here is how things work: The switch should ( and usually does ) switch on at one ( high ) level and then switch off as another level ( low). If the amount of back flow is relatively high, then it will cause the level to rise to/above the "on" position. The cure is to increase the hysteresis. You can do this by changing to a different switch, which may ( but is not guaranteed to ) have greater hysteresis, or you can take the easy route and increase the surface area of the sump box, which means that the same back flow will cause a smaller increase in water level. A one-way valve, in theory, should work. In practice, esp in this situation, they will fail often, becoming a constant maintenance item.

Cure the problem; change the sump box. IMO.
 
quote:
Originally posted by PascalG

a check valve is the last thing you want to put in a shower sump as sooner or later it will clog up. at best it won't work, at worst it will prevent discharge.

Click to expand...

I included that warning in my post. The OP said he couldn't find one.

This might be a little drastic, but my shower has no sump. There is a pump that supposedly can run dry for a few minutes. You're supposed to switch it on, take your shower, then switch it off.

I've never used it, we shower outside in the cockpit. It has a gravity drain.
 
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