Using delay with HTML or text setting doesn't work

delay() defaults to the animation queue, for effects like fadeOut(), etc. You should use setTimeout() instead:

window.setTimeout(function () {
    $("#element").html(' ');
}, 3000);

From http://api.jquery.com/delay/:

jQuery.delay() is best for delaying between queued jQuery effects and such, and is not a replacement for JavaScript's native setTimeout function, which may be more appropriate for certain use cases.

.html() isn't a queued function. If you want it to happen in order in the animation queue, you'll have to .queue() it yourself, like this:

$('#element').delay(3000).queue(function(n) { 
  $(this).html('&nbsp'); n();
});

If you're not chaining animations or anything like this, use setTimeout() or setInterval() (whichever is appropriate to the situation) directly, .delay() is just a wrapper for setTimeout() and there's no reason to use extra code/complexity when there's no need.