Hi, I am a recent landlady, I decided to let my house in February after it being on the market for eighteen months, they are many rules and regulations covering the tenants and landlord/ lady. We have had to have all the electrics tested, and if there is gas this has to be tested, as a landlady I would be happen to repair anything that was wrong, check what your tenancy agreement says and contact your letting agent, if it is private let, you still have rights, and the mould problem should be sorted.