Thanks guys, apologies if this sound daft but im the perfect example of the accidental DBA. Having come from a job with no exposure to clulstering and SQL (previous job was in schools) im still working this out in my head.

I have 3 network cards on the VMs all connected to different distributed switches which are tagged on different VLANs. How do i go about using a different network for the heartbeat as i cannot see anything related to this on the existing virtual cluster and physical cluster, only the public and 2 private iSCSI vlans are listed in failover manager.

From what i read when looking into this it is suggested that a heartbeat isn't required any more from SQL 2008 onwards? If this isn't recommended would another network card on each server on the same VLAN configured with a private IP (192.x.x.x for example) be enough for the heartbeat? obviously this would be set to Cluster use only?