With about six weeks left in 2010, the Internal Revenue Service is reminding homeowners that there is still time to take advantage of substantial tax credits for weatherizing their homes and initiating other energy-saving efforts.

Last year’s Recovery Act expanded two home energy tax credits: the nonbusiness energy property credit and the residential energy efficient property credit.

The Nonbusiness Energy Property Credit equals 30 percent of what a homeowner spends on eligible energy-saving improvements, up to a maximum tax credit of $1,500 for the combined 2009 and 2010 tax years. The cost of certain high-efficiency heating and air conditioning systems, water heaters and stoves that burn biomass all qualify, along with labor costs for installing these items. In addition, the cost of energy-efficient windows and skylights, energy-efficient doors, qualifying insulation and certain roofs also qualify for the credit, though the cost of installing these items does not count, according to the IRS.

By spending as little as $5,000 before the end of the year on eligible energy-saving improvements, a homeowner can save as much as $1,500 on their 2010 federal income tax return. Due to limits based on tax liability, amounts spent on eligible energy-saving improvements in 2009, other credits claimed by a particular taxpayer and other factors, actual tax savings will vary. These tax savings are on top of any energy savings that may result.

With the Residential Energy Efficient Property Credit, a homeowner can get a credit equal to 30 percent of what they spend on qualifying equipment, such as solar electric systems, solar hot water heaters, geothermal heat pumps, wind turbines and fuel cells. Generally, labor costs are included when figuring this credit. Also, except for fuel cell property, no cap exists on the amount of credit available.

Not all energy-efficient improvements qualify for these tax credits. For that reason, homeowners should check the manufacturer’s tax credit certification statement before purchasing or installing any of these improvements, the IRS said. The certification statement can usually be found on the manufacturer’s website or with the product packaging. Normally, a homeowner can rely on this certification.

The IRS cautions that the manufacturer’s certification is different from the Department of Energy’s Energy Star label, and not all Energy Star labeled products qualify for the tax credits.

Eligible homeowners can claim both of these credits when they file their 2010 federal income tax return. Because these are credits, not deductions, they increase a taxpayer’s refund or reduce the tax owed. An eligible taxpayer can claim these credits, regardless of whether he or she itemizes deductions on Schedule A . Use Form 5695, Residential Energy Credits, to figure and claim these credits.