buzzing noise from shower sump pump

[Captain Mike]

2016 R 25 Buzzing noise coming from the area of the hot water tank. General discussion via the forum helped me to isolate the noise. By pulling the shower sump pump fuse I was able to stop the noise.
Now what? what does this pump do, we have never used the shower. I assume this pump remove water from the floor drain in the bathroom.
Where is this pump located, the sound seemed to come from behind the hot water tank. I can see no wires or access from under the bathroom sink so how does one get to this pump to find out what is going on?
Thanks in advance

 

[Cessna172]

Not sure on the R25; but on my C28 the sonar transducer is located next to the shower sump.

When the sonar is set for 50 hertz, a clear and sometimes annoying buzz can be heard coming from that area. When set at 200 hertz the transducer cannot be heard.

 

[jlhowland]

Probably the float switch on the shower sump. they fail periodically causing the pump to run continuously. Several other posts are active on the topic with potential solutions.