The property_bedrooms is forced by the system to be a integer number. If you change this the search results that involve bedrooms will not work corectly.
If you still want to change this to the text format you should search in the theme folder for all occurences of property_bedrooms and where you see
$property_bedrooms = floatval ( get_post_meta($post->ID, ‘property_bedrooms’, true) );
$property_bedrooms = intval ( get_post_meta($edit_id, ‘property_bedrooms’, true) );
replace intval or floatval with esc_html
Also i suggest to consider using a custom field rather than doing this change.
Before doing any change make a backup – just in case things not work well.