"The existence of waiver or estoppel depends on the facts and circumstances of each case." Leader Natl. Ins. Co. v. Eaton (1997), 119 Ohio App. 3d 688, 692, 696 N.E.2d 236, citing Hounshell v. Am. States Ins. Co. (1981), 67 Ohio St.2d 427, 424 N.E.2d 311. In Leader, the court held that payment of a claim by an insurer, with knowledge of a potential defense against coverage and without any reservation of rights, waived the defense. The doctrine of waiver also has been held to apply "when the insurer, by its acts or declarations, evidences a recognition of liability under the policy, and the evidence reasonably shows that such expressed recognition of liability and offers of settlement have led the insured to delay in bringing an action on the insurance contract." Hounshell, supra at 431. However, the Ohio Supreme Court has held that, generally, "the doctrine of waiver cannot be employed to expand the coverage of a policy." Hybud Equip. Corp. v. Sphere Drake Ins. Co., Ltd. (1992), 64 Ohio St.3d 657, 668, 597 N.E.2d 1096.