In the Guide, simply right-click on a channel's current program and select Watch Live TV:

When a user attempts to watch Live TV, SnapStream finds the lowest priority Tuner available to provide playback. If all Tuners are being used for recordings, then the UI will display an error message stating as follows:

There are no available tuners to watch this channel.

If a user selects Watch Live on a program that is being recorded, it doesn't change the status of the Tuners or recording priorities. If you select Watch Live TV for a recording in process, you'll notice that, depending upon the SnapStream version, the interface will be different.