wrong php file being used on homepage

Hi

I have inherited a site which has its own template. I was trying to make a modification and I have somehow messed up the hierarchy (I think)

In the template are page.php, index.php and page-custom-home.php

For the site homepage it used to pull up page-custom-home.php. Only now it doesn’t- its pulling up page.php and it would be really helpful if I could make it use page-custom-home.php again.

If anyone could help I’d be very grateful

Thanks

Edward