UK Landlord Forum / Life

hi, We have recently moved from  office/unit premises we have been renting since 1st May 2007.on leaving the premises we had to provide a gas and electrical report. We subsequently did so and the report from the electrician failed due to the unit did not have an RCD unit installed. The landlord is refusing to refund our deposit as he says that it is the tenants responsibility to have one installed.....Is this correct?