Because when water freezes it expands thus bursting the pipes.

There are a number of reasons why pipes might hum when they are turned on. A washer could be worn out and not working correctly. The fill valve on one of the toilets may not be working properly, or it could be your water pressure.

water expands on freezing

A plumber installs water pipes.

Aqueducts were large water pipes and they were used to bring water to wherever it was needed.

Aqueducts were large water pipes and they were used to bring water to wherever it was needed.

Aqueducts were large water pipes and they were used to bring water to wherever it was needed.

Aqueducts were large water pipes and they were used to bring water to wherever it was needed.

Aqueducts were large water pipes and they were used to bring water to wherever it was needed.

Aqueducts were large water pipes and they were used to bring water to wherever it was needed.

Aqueducts were large water pipes and they were used to bring water to wherever it was needed.

Aqueducts were large water pipes and they were used to bring water to wherever it was needed.

Aqueducts were large water pipes and they were used to bring water to wherever it was needed.