Without having a stop in the run you'll have to turn off the system, unless...If it is the hot water side you can turn it off at the water heater.
Isolate it from the water supply then replace the defective valve
It means to shut off the water feed to the washing machine.
Stop Valve Key
primary flow
Cold feed
primary return
Cold feed
never
Usually there is a shut off valve right above the water heater on the cold side. There can be one on the hot side to so that the heater can be removed without having to drain the system.
on internal cold water supply pipework is wrong answer
primary flow
Sublimation