Dividend investing is a tried-and-true strategy for generating strong, steady returns in economies both good and bad. But as corporate America's slew of dividend cuts and suspensions over the past few years has demonstrated, it's not enough simply to buy a high yield. You also need to make sure those payouts are sustainable.

Let's examine how Whirlpool (NYSE: WHR) stacks up. In this series, we consider four critical factors investors should examine in every dividend stock. We'll then tie it all together to look at whether Whirlpool is a dividend dynamo or a disaster in the making.

1. Yield
 First and foremost, dividend investors like a large forward yield. But if a yield gets too high, it may reflect investors' doubts about the payout's sustainability. If investors had confidence in the stock, they'd be buying it, driving up the share price and shrinking the yield.

Whirlpool yields a moderate 3.9%, quite a bit higher than the S&P 500's 2.1%.

2. Payout ratio
 The payout ratio might be the most important metric for judging dividend sustainability. It compares the amount of money a company paid out in dividends last year to the earnings it generated. A ratio that's too high -- say, greater than 80% of earnings -- indicates that the company may be stretching to make payouts it can't afford, even when its dividend yield doesn't seem particularly high.

Whirlpool has a payout ratio of just 40%.

3. Balance sheet
 The best dividend payers have the financial fortitude to fund growth and respond to whatever the economy and competitors throw at them. The interest coverage ratio indicates whether a company is having trouble meeting its interest payments -- any ratio less than five is a warning sign. Meanwhile, the debt-to-equity ratio is a good measure of a company's total debt burden.

Whirlpool has a debt-to-equity ratio of 58% and interest coverage of four times.

 4. Growth
 A large dividend is nice; a large growing dividend is even better. To support a growing dividend, we also want to see earnings growth.

Over the past five years, Whirlpool's earnings per share have shrunk at an annualized rate of 7%, while its dividend has grown at a 2% rate.

The Foolish bottom line
Whirlpool exhibits a reasonable dividend bill of health. Its high yield appears affordable given the company's low payout ratio. Dividend investors will want to keep an eye on the company's earnings growth, however, to ensure that it's able to continue raising its dividends over the long term. To stay up to speed on Whirlpool's progress, or that of any other stock, add it to your stock watchlist. If you don't have one yet, you can create a free, personalized watchlist of your favorite stocks by clicking here.