Puzzling faucet leak

[Andy K]

When I turn on the hot water faucet water leaks from the cold faucet. When I turn on the cold faucet no leak occurs. Why does this happen and how to address it?

 

[Twowaxhack]

Replace the cold cartridge.

 

[Andy K]

Replace the cold cartridge.

Thanks! Curious as to how turning on the hot faucet causes the cold faucet to leak?

 

[Twowaxhack]

Thanks! Curious as to how turning on the hot faucet causes the cold faucet to leak?

Because back pressure is applied to the cold side when you turn the hot on.

The cold cartridge has an oring that could possibly be replaced, sometimes it requires a complete cartridge.

 

[Andy K]

Because back pressure is applied to the cold side when you turn the hot on.

The cold cartridge has an oring that could possibly be replaced, sometimes it requires a complete cartridge.