For years, Americans used the equity in their homes to give themselves a little extra financial breathing room, but a half-decade of consistently dropping home values and the overall economic malaise felt by America's middle class has left many with less ability to pay back the bigger bills.

Many of the HELOC customers are also now moving into retirement mode, trying to save whatever meager earnings they can, and the prospect of yet another bill looming on the horizon may come as a shock to more than a few.

Homeowners are obligated to make those HELOC payments or, like so many other Americans have experienced, they can quickly slip into foreclosure.

It's a tangible issue, especially for those who are literally counting their pennies as they plan on their monthly costs without a regular income: a $50,000 loan at 3 percent might have just been costing $125 a month, but at a payback rate of 5 percent, plus principal, retirees could find themselves shelling out nearly $500 per month.

And that's counting on the current, incredibly low interest rates: many HELOCs feature a variable rate that could skyrocket at exactly the wrong time.

Best advice for your pre-retiree clients? Pay off that line of credit, if you can, or start to make more aggressive payoffs while the paychecks are still coming. They may also consider refinancing, if possible, though transfer fees often eat up much of those potential savings.

There are also more complex options to consider, including a reverse mortgage, though those controversial and now more-frequently advertised products also carry their own risks.