This will depend which model of Humax recorder you have. You have posted this in the DVD section and have not stated which model you own.
Note that currently the Freeview HDR-2000T cannot pass the signal through in standby, but there may be a fix later in 2014 when a power saving option menu is expected to be introduced.
For other DTT models check the power saving option menu.
Neil S, August 2014