I was told I could claim my whole house generator. how do i do that

You can not deduct the expense to purchase and install a whole house generator on your tax return.  This is considered a capital improvement and is added to the basis of your home. Your basis is used when you sell to determine capital gain or loss. 

 A capital improvement is something that actually adds to the value of the home or increases its usefulness.  Some examples of capital improvements are:

• Remodels and room additions (including decks and porches)
• New or upgraded landscaping, irrigation, sprinkler system
• Hardscape such as pavement, block or retaining wall, patio
• Fencing
• Swimming pool, spa
• Storm windows, doors
• New roof
• Central vacuum or security system
• Upgraded wiring, plumbing, ductwork
• Central heating, AC, humidifier
• New furnace, water heater
• Filtration, soft-water, or septic system
• Built-in appliances
• Whole house generator
• New flooring or wall-to-wall carpeting
• Upgraded insulation
• Satellite dish

You can not deduct the expense to purchase and install a whole house generator on your tax return.  This is considered a capital improvement and is added to the basis of your home. Your basis is used when you sell to determine capital gain or loss. 

 A capital improvement is something that actually adds to the value of the home or increases its usefulness.  Some examples of capital improvements are:

• Remodels and room additions (including decks and porches)
• New or upgraded landscaping, irrigation, sprinkler system
• Hardscape such as pavement, block or retaining wall, patio
• Fencing
• Swimming pool, spa
• Storm windows, doors
• New roof
• Central vacuum or security system
• Upgraded wiring, plumbing, ductwork
• Central heating, AC, humidifier
• New furnace, water heater
• Filtration, soft-water, or septic system
• Built-in appliances
• Whole house generator
• New flooring or wall-to-wall carpeting
• Upgraded insulation
• Satellite dish