measuring for water heater door

[Paula Schneider]

The water heater door needs to be replaced. I know that the measurements for a new door are for the size of the opening. So, how do I do that? Thanks in advance!

Paula

[Mark Bower]

The lengths are usually the same, just need to know the width. Measure the raw width as if the door wasn't there. The frame of the door isn't very thick tho.

Mark
You gotta see my repair manual!