Funding of the Excess. If an Insured fails to pay to a Claimant any amount which is within the Excess within 30 days of it becoming due for payment, the Claimant may give notice of the Insured’s default to the Insurer, whereupon the Insurer is liable to remedy the default on the Insured’s behalf. Any amount paid by the Insurer to remedy such a default erodes the Sum Insured.