Separate names with a comma.
If you are running the DWC / RRF; then you need to look at the system files tpre(n),tpost(n) and tfree(n) [where n is the tool number 0,1,2,3]...
From the TCM build guides re:Commisioning and Hotend Fan Checks this was in the comments: "For me clicking on the tool name in the heater column...
