The user guide I find online for that model advises that there is a 30-min Soak option. The machine will auto-drain and cancel the cycle after 60 mins of pause. A workaround for a longer soak is disconnecting the power (pull the plug or turn off the circuit breaker). It may resume the cycle at restoration of power, or it may abort the cycle and drain. Someone who owns the model perhaps can advise you.

I agree with what Dadoes stated above. This is your best bet for soaking in the machine for a prolonged period of time.

For what it is worth, to have a true hot wash, you will likely need to use the Sanitize cycle or a cycle permitting the use of Extra Hot water setting.