If you hold property for rental purposes, you may be able to deduct your ordinary and necessary expenses (including depreciation) for managing, conserving, or maintaining the property while the property is vacant. However, you cannot deduct any loss of rental income for the period the property is vacant. 

The IRS usually classifies renting as a "passive activity." If your house sits empty so much that you wind up spending more on the house than you made, you cannot deduct your losses from any income except other passive activities.[they will carry forth] Section  469(i), which allows a limited deduction for a loss attributable to a rental real estate activity.

Generally if you do not rent it for 18 months, then you're not trying and it looks like tax evasion.

 The key in this  is that the property was available for rent and the owner was looking for a tenant, even though he or she hadn't found one yet. 

Your rental property, if vacant, is available for rent and that you (or your manager) are actively looking for tenants!the IRS may disallow expenses if there is a loss for 3 or more years...much like the hobby rules.

The lack of evidence of a rental property business strategy,and the fact you have no cash flow generate from the property.You should be trying to generate revenue and if what you try does not work, you should try something else.  And be able to document it.