I had been toying with the idea of putting a flood detector in my shower to detect if there was someone in the shower. I had discounted a Contact sensor on the shower door as there is just too many variables to reliably detect if someone is in the shower.
The problem i was having is that my lighting was turning off when you were in the shower as the motion detector wasn’t detecting movement, I settled on the I used an Everspring ST812 Flood Detector and i’ve seen another post where someone put the probes of this in their waste pipe. however i wasn’t that happy with this as i have seen the insides of shower waste pipes after a few years and they do get gunked up, and since i don’t want to be dissembling my showers plumbing every few years to clean i thought it would be best placed in the shower trap where i can also get access to the probes to clean when necessary.
here is a photo of the probes installed just above the level of waterline of the standing water in the shower trap when the shower is off.
and then when the water flows the level increases slightly and submerges the probes and registers that the water is flowing. it is accurate and very quick the detect the shower is on and off, before this i was increasing the timeout to 8 minutes for the morning getting up period, however i found this deficient when i was going out of the night and having a shower where the timeout was 2 minutes . and setting the light for 8 minutes all day IMHO is just a waster of power.
here is a video of me testing the sensor in the shower trap before i installed in the shower. excuse me getting a bit over excited at the end of the vid…i dont get out much