I've got a shower head attached to the wall by a long metal covered flexible hose. The shower head stays attached to the wall so there is a long loop of hose hanging down between the wall and the actual shower head. When I turn the water off, the flow immediately stops. After a minute or two the water that was in the loop will start dripping out of the shower head on it's own fairly quickly. There's no leaking valve, so it's not new water pushing out the old. Any explanation?


Once the shower is turned off and the shower diverter lever is pushed down, excess water in the vertical shower standpipe (inside the wall) falls backward so most of the water drains into the tub through the tub spout. During this process, an airlock develops in the standpipe, trapping water in the horizontal portion of the shower arm and also in the showerhead.

Inside the showerhead near the back is a flow restrictor which may restrict air entering the system, air that would normally help to completely flush out the water once the shower diverter lever is pushed down.

From Plumbing And Showers

  • $\begingroup$ How would trapped hot water push it out? If it's allowed to cool down for a few minutes I wouldn't expect that. $\endgroup$ – JMac Aug 14 '17 at 20:37
  • $\begingroup$ @JMac. Spot on, the dripping in my shower drives me crazy, but it is half physics, half engineering in my opinion. No, actually it's mostly engineering, in my opinion, it varies from shower to shower, I would bet. $\endgroup$ – user163104 Aug 14 '17 at 20:43
  • $\begingroup$ We have 2 showers and they both work differently. One works the way it was described in this post, and other one works with just a thumb shutoff value - it dripped all the time. We had to replace the thumb shutoff with a straight value quarter turn shut-off. $\endgroup$ – Cinaed Simson Jun 8 at 8:22

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