If your appliances are part of your rental agreement, you need to tell your landlord if they’re not working. You’re entitled to functioning appliances, and it’s your landlord’s responsibility to fix or replace them. As well, if you don’t say anything, when it’s time for you to move out, your landlord may withhold your security deposit.
Even if the appliances are your responsibility, always let the landlord know when you’ve arranged for a repair person to come to the apartment. Otherwise, she may suspect you of trying to hide an issue.