I am sure you have already solved this issue with your lender. I just wanted to mention after reading your question, that in this market with so many people not paying their mortgage and attempting loan modifications and short sales..that as long as the payments are made every month on time, they probably won't call the loan due. I would consult many lenders to get opinions.
According to FHA guidelines, the lender must certify that the buyer will occupy the dwelling within 60 days of closing and continuously occupy for at least 12 months.
If your husband occupied the dwelling for at least a year after closing, he has met and fulfilled FHA's requirements. The lender does not have any rights to dictate whether a mortgagor (home owner) may or may not rent out a home with an FHA insured mortgage after the occupancy requirement has been met. Such a requriement from the lender is not supported anywhere in FHA guidelines and may possibly interfere with "quiet enjoyment" of your fee estate.
FHA permits a borrower to hold more than one FHA mortgage at a time under certain exceptions. An increase in family size, (eg getting married) is one of the exceptions. Relocating closer to work to make a more reasonable commute is another.
You mentioned that your husband has passed. Technically, the mortgage held by him must be paid off even though you have inherited the home since you are not a borrower on the condo loan.
The lender may, at its option, forgo exercising the due-on-sale clause (the home was transferred or "sold" to his estate)... but it sounds like the lender sees an opportunity to earn a fee for refinance and otherwise performing note. You cannot assume the FHA mortgage from your husband's estate unless you certify that you will occupy the condo.
I suggest speaking with a supervisor in the loan servicing department to see if they are willing to keep your late husband's mortgage "open" rather than asking about how you intend to use the property.
Best of luck!