Should headings always use the same font as the body?

I’m working on some of the layouts for a User Handbook and right now my main concern is fonts. I’m trying to decide whether to use the same font for the body text and the headings.

If I use different fonts (along with the larger type and bolding), that will draw attention to headers and make it easy to skim. However, using the same font is more consistent and may be smoother to read.

Should I always use the same font for headings for readability purposes? What if I’m starting a new chapter as opposed to a new section?