Zero non-formula values in a column

[Santana20]

How can I set all non-formula and non-blank values in a selected column to zero?

[teylyn]

Enter a zero into a cell, any cell will do. Copy the cell.

Select the column
Hit F5 and click Special
Tick Constants and OK
Paste with your favourite Paste command (I like Ctrl-V)

Constants are any values that have been entered manually (or copied/pasted) so this method will paste over numbers as well as text.