Rule 1654. Defendant

(a) The plaintiff shall name as defendant the owner named in the claim and the owner, if known, at the time the action is commenced.

(b) If the last owner of record prior to the commencement of the action has died, the plaintiff shall name as a defendant the personal representative, heir or devisee of such owner, if known. Official Note For definition of owner see section 201(3) of Mechanics’ Lien Law of 1963, 49 P. S. § 1201(3).