Replacing Shower Sump Box Bilge Pump— R27 Classic

[CaspersCruiser]

The Rule model 20R bilge pump used in the shower sump box installed in my 2012 R27 failed. That bilge pump model is no longer available. The same shower sump box may be used in all R27 Classic model years 2011-17 since their heads are configured the same. Here’s a work around to keep that shower sump box in operation.

The shower sump box is very shallow and only two current production Rule bilge pumps will fit inside it— the 24DA and the 25DA. I selected the 25DA because it has a higher GPH rating and uses less power.

The pump discharge configuration of the 25DA is different from the 20R. The 25DA has a longer discharge fitting with a barbed end that meets the sump box outflow fitting perfectly. Both are 3/4” outside diameter. To join the two fittings, I used a 3-inch section of 3/4” inside diameter clear plastic hose to mate the 25DA barbed end with the sump box outflow and secured them together with a stainless steel hose clamp.

The reason the 25DA discharge is longer than the 20R discharge is the 25DA has an integral back flow preventer inside the discharge. The 20R used a different arrangement.

That’s it for the pump replacement, but if you have to replace that pump, here’s a modification you might consider while you’re at it. The float switch used in that shower sump box is notoriously unreliable. After the float switch on my R27 failed ON, I removed the float switch and replaced it with a manual switch. How I did so is detailed in this post from July 2022:

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Thread 'Replacing Shower Sump Float Switch With Manual Switch'

Jul 4, 2022

The Rule-A-Matic Plus float switch in the shower sump on my 2012 R27 failed ON no matter the position of the float. The only way to stop the shower sump bilge pump from running was to remove the fuse for it in the Power Distribution Panel under the port side hinged step.

From all of the posts about it here on Tugnuts, that float switch has a poor service record of failing OFF or ON or the float sticking in the UP or DOWN position. Several Tugnutters have removed that float switch from the sump box and installed a manual ON/OFF switch.

I made that modification on my boat today. It...

• CaspersCruiser
• Replies: 3
• Forum: Owner Customizations

I don’t often use the shower on my boat, but I do use it when anchored out or if I’m at a transient slip in a marina where the shower facilities are less than desirable.

 

[William Sanborn]

What is your secret for getting the lid off of the sump box. I pulled the fuse a long time ago and have gotten pretty handy and putting in and taking it out, but would like to either install a manual switch or a fool proof float switch.

 

[CaspersCruiser]

I have edited the original post to correct the model number of the old Rule bilge pump. The correct model number of the old pump is the 20R. I mistakenly wrote that it was a model 30R bilge pump.

 

[CaspersCruiser]

What is your secret for getting the lid off of the sump box. I pulled the fuse a long time ago and have gotten pretty handy and putting in and taking it out, but would like to either install a manual switch or a fool proof float switch.

The lid is held down by four Phillips head screws, one in each corner of the lid. The back two screws require a very short stubby screwdriver or a right angle screw driver.

I recommend installing a manual switch to operate the bilge pump. A foolproof float switch that will fit the very small sump box does not exist. The OEM float switch has four failure modes. Mine failed ON. It wasn’t stuck. The float activated the switch ON and it stayed on after the float returned to its rest position. I had to pull the fuse to shut it off.