When filling up the water tank, there is water going into the
overflow tube (throug a small black tube connected to the
floatmaster). What's the purpose of that water flowing?

John Smith wrote:

When filling up the water tank, there is water going into the
overflow tube (throug a small black tube connected to the
floatmaster). What's the purpose of that water flowing?

To make sure the bowl trap has water in it.

--
Grandpa

What is that dripping from my fingers?
Why it looks like time.