Does changing theme effect my rankings?

So i recently hit #1 position for 1 local keyword and i want to change the theme, since i first started of making it ecommerce store but traffic volume is low, so i am thinking of making a static home page(i will try to add quite similar content but just remove buy now buttons maybe) so visitors can contact us when they visit home page while inner pages will remain same as they were before. Do you think this can effect my rankings?

If the content doesn't change, a theme/design change shouldn't interfere with the rankings. Depends a lot on your definition of "quite similar content", the less you change, the less risky. Removing just a few buttons won't have a negative effect.

Don't panic if you see some small temporary drop, sometimes Google re-evaluates sites when a lot of code or the site structure changes, but rankings normally return quickly.

I think you should not change the heading keyword position and the contents and everything will be completely fine. Changing the theme just changes the back-end code and that is not crawled by google so you will be fine unless the content is not changed.

I've just delayed a project for exactly the reason that I don't want to be in this position.

We have a local niche in which we rank well in one city, but the site doesn't convert the way it should, so we're experimenting with new designs before we start hunting down rankings in other cities. I just take the view that it's 'better' to rank with the long term site, rather than a temporary site that will be changed in the immediate future.

That said - you should be fine, as long as you leave the critical on-page elements unchanged (metas, headers, alt tags, keyword incidence, etc).

If you are going to change the theme only than it's fine. The change in theme doesn't going to affect your website's ranking. But you have to be very careful while doing this task because a little change in the On page of the website can effect the ranking. So, don't make any change in the meta tags and other on page files which are essential for the website's ranking.

Well, one of my client changed from some coded HTML to WordPress the site was ranking very well before that, after the change the site got total removed from Google and is still not to see anywhere, so I think you have to be careful doing such changes if you rank well.

It can be a risk, absolutely. Most themes change the fundamental architecture of the site. Which in turn can change the way that these pages are linked internally.

Obviously you can be sure that the widgets are setup the same way, but you are still gonna deal with some internal linking structure changing. My recommendation would be to take screenshots of your current theme and all of the important pages and then make sure you replicate them the best way possible with the new theme.

Your rankings will probably drop a bit, however you'll get them back in no time.