Many closed mortgages have the feature that allows the balance to be paid out with a penalty after a certain time has elapsed on the mortgage. Check the "prepayment" clause in your mortgage to determine your own situation, or better still, call your institution and ask them the cost of paying out in full. 

Either of the following situations could apply to you:
 
 

• There is a penalty of 3 months interest or "Interest Rate Differential" (IRD) whichever is greater. Your new lender will be happy to discuss your options for financing this penalty. 
• The mortgage is closed, and can only be "opened" at the discretion of your current mortgage lender. Well, you're truly stuck, and you may only be able to "blend and extend" into a longer term, depending upon how charitable your current lender is feeling. Many lenders have made the mistake of not giving their customers any concessions. This approach is very effective for the term of the mortgage, but seldom beyond.