Old Carrier Wall PAC (PTAC) 52xx series Parts source?

Hi, No heat. Suspect heating element is gone. Where to get parts? I understand this units are no longer made.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.