Exactly one week after the Federal Reserve announced plans to make billions worth of home loan purchases, mortgage rates returned to record low levels yesterday, according to Freddie Mac’s latest weekly mortgage rate survey.

According to the Freddie Mac survey for the week ended September 20, 2012, 30-year fixed-rate mortgages averaged 3.49 percent, matching the record low set late in July.

Last week, 30-year fixed home loans were at 3.55 percent. A new historical low was set for 15-year fixed-rate mortgages; average rates tumbled from 2.85 percent last week to 2.77 percent as of yesterday. The previous record low was 2.80 percent, set at the same time as the record for 30-year fixed loans.

Last Thursday, the Fed confirmed that it would buy $40 billion a month worth of mortgage-backed securities, a move known as quantitative easing, or QE3, as this is the third implementation. QE3 is intended to drive further recovery for the country’s housing market and overall economy; this would lead to lower mortgage rates, thus better opportunities for homeowners to refinance.

Home loan specialists believe that the record-low rates set this week are merely scratching the surface of what the Fed can do through QE3. HSH.com Vice President Keith Gumbinger said that “the full effect of the Fed’s influence” has yet to be felt by the housing market, as a slowdown in activity would be needed to see how low the rates can really go.

Last year, mortgage rates were at 4.09 percent for 30-year fixed-rate mortgages, so borrowers can potentially save more than $1,000 annually if they would refinance now.