How do I properly set up the air valve before inflating for the first time?

When using the board for the first time or after long-term storage, check the air valve and tighten it with the provided wrench first. Do not rotate the wrench counterclockwise when inspecting the inflation, as this is dangerous. Also ensure the inner spring valve is not depressed before attaching the pump. (Page 1)

From the official Bestway Inflate Flocked Airbed manual, page 1

Have a follow-up question?

Answers from the official manual.

Common questions