Physics Van 3-site Navigational Menu

Physics Van Navigational Menu

Q & A: hot water draining slowly

Learn more physics!

Most recent answer: 12/29/2019
Q:
I have above the counter rectangular sinks in my bathroom. They have pop in drains that fit into drain hole. Push down on the top of the plug and is closes and push down again, it opens to allow water to drain. When I use hot water, it takes an unusual amount of time to drain. Cold water goes right down the drain without a problem. Can you explain? this?
- Jeff Zornow (age 63)
Fairport, NY USA
A:

All I can do is guess. That switchable drain valve may have a pretty small opening. Maybe there's a control rod that expands when it gets hot and allows it to partially close. That's a little surprising because most metals don't expand much in hot water, but at least it's possible. Or perhaps there's a plastic part that softens and allows the valve to close some.

Mike W.


(published on 12/29/2019)

Follow-up on this answer.