ELI5, How does the water temperature change in a sink and shower?



Also, why does flushing a toilet make the water hotter?

In: Engineering

Mixing valves and far as your toilet, you probably have a crossed hot water line somewhere.

The plumbing connects with a hot water heater, which preprepares an amount of hot water for your sink and shower. But there is also a cold water pipe, which bypasses the water heater.

If the plumbing is done wrong, and the water diverts from the toilet intake to the shower, then flushing the toilet kills the cold water running into the shower, leaving you with only hot water flowing.

As for the temperature of the water, it is regulated by mixing the hot water from the heater with cold water from outside the heater. The more you open the hot, the hotter it gets, because there is more hot water than cold.

There are 2 supply lines that connect under the sick to the faucet, one with cold water and hot water that’s been heated in a hot water heater. The ratio of hot to cold it determined by the faucet, adjusting the temperature.

The toilet only uses cold water, so a flush can divert water from the pipes to the toilet and momentarily reduce the cold water going to the sink — throwing off the ratio until the pipe’s pressure adjusts to supplying 2 fixtures.