Is having a word with the H1 tag the same as having a 24 pt bold word in terms of SEO?

[Ryan S]

As above really.

I want to have an H1 heading for a webpage but for some reason the H1 setting doesn't seem to be working and applying to my title. However if I bold the word and put a 24pt size on the word this visially has the same effect as the H1 tag,

Will search engines see this the same way? Will they notice the difference between me using an H1 tag to manually altering it all? Does it have the same SEO?
Hi Smelly Cat, thanks for the quick response! I'm getting my web designer to look into it now so hopefully it'll be sorted very soon indeed. I'm new to starting out about optimisation and just as I suspected it wouldn't look the same to the search engines.

Would it be okay to H1 tag the title and then alter the size anyway so that it has a number of different attribues (for example an H1 tag, a bold tag and also a 24pt tag). I've checked the HTML and it still tags it as H1 actually.