Displaying posts by tag

Hi-

I’m trying to make a custom page template for a real estate property.

I want to display all rental properties on one page.

This is the existing code for the property page;

global $wp_query;
$wp_query = new WP_Query('post_type=property&post_status=publish&paged='.$paged.'&showposts='.$numpost);
get_template_part( 'loop', 'property' );
wp_reset_query();

I tried putting in:

global $wp_query;
$wp_query = new WP_Query('post_type=property&tag=rental&post_status=publish&paged='.$paged.'&showposts='.$numpost);
get_template_part( 'loop', 'property' );
wp_reset_query();

But that is not working. What do I need to edit to get the property posts with the tag ‘rental’ to display? I’m currently getting a ‘there is nothing to display’ message. And I have checked to make sure my property tag of ‘rental’ is spelled correctly in the property tags.

Thank you!