Increasing your deductible will actually lower your premium. The total amount will depend on your individual policy, but you will see a decrease in your monthly payments (or receive a prorated refund if either you or your mortgage company paid in full) after you confirm the change with your insurance company.
The main reason carrying a higher deductible gives you more of a discount is because you are taking on more of the risk inherent in the policy. Insurance companies are responsible for paying the amount it will take to repair or replace the damaged or lost property minus the deductible and subject to the limitations on the policy. With a higher deductible, the insured is pledging to pay more of the loss amount. As an example, say your roof is damaged in a windstorm and the adjuster determines it will take $3,000 to repair it. With a $500 deductible, the amount the insurance company pays out is $2,500 while the insured pays $500. With a $1,000 deductible in the same scenario, the insured receives $2,000 and is responsible for paying the remaining $1,000 to complete the repairs.
There are several deductible options beyond $500 and $1,000, so be sure to discuss them with your Licensed Agent and see which is best for you.