Of all the appliances in your home, your water heater is probably the most inconspicuous. Tucked away in the basement or a closet, you hardly know it's there -- until it breaks down.

An inoperative water heater means cold showers until you can get it repaired or replaced. Often it can be a frustrating experience.

Emily, a consumer in San Dimas, California, said she bought a 50 gal, nine-year warranty, Whirlpool Ultra Low Nox Gas Water Heater from Lowes in November 2007. On November 22 this year, she said the control valve failed.

"We returned to Lowes and were told they could do absolutely nothing for us, that we needed to contact Whirlpool and be without hot water for who knows how long in the process," she told ConsumerAffairs.com. "This morning I contacted Whirlpool and after being placed on hold for nearly 15 minutes they hung up on me. I then decided to take a look at Lowes' website and saw that it was riddled with comments from unhappy customers who purchased these hot water heaters. It is obvious to me that Lowes knows that these products are defective yet they continue to sell them to unsuspecting customers such as myself."

The Whirlpool water heater has drawn hundreds of complaints from consumers over the years, and the company settled a class action lawsuit earlier this year, but it is by no means the only water heating device giving consumers a case of heartburn.

Ludwig, of Palmdale, California, bought a GE water heater at Home Depot last June. He said it worked fine for about a week.

"Suddenly the water heater burner was smothering. After carefully following the troubleshooting instructions it said that if the water heater kept on turning off, then I had to call the gas company for inspection," he told ConsumerAffairs.com.

Ludwig said the gas company inspected his water heater and told him it was defective. Not only that, it was not to be turned on again, the technician said, because it was dangerous.

What followed, Ludwig says, was an excruciating and frustrating run-around by GE.

Other brands have also caused consumer headaches. Two years ago Delta Combination Water Heaters were recalled because the burner plate and flue hood seal on the water heaters could fail due to an improper seal causing a leak of flue gases and carbon monoxide.

Most water heaters are powered by either electricity or gas, which is used to heat metal elements in a tank of water. It's a fairly simple device, but in recent years seems to have become more troublesome for some reason.

Though no scientific studies have been done on the subject, it seems from complaints received at ConsumerAffairs.com that gas heaters have more problems than electric ones. That may have to do with gas heaters' venting requirements and other safety features.

Now, GE is turning to the sun to provide hot water. The company last month announced it is developing a line of solar water heaters.

"GE re-entered the water heating business about ten years ago," said Kevin Nolan, Vice President Technology for GE Consumer & Industrial. "GE has recently driven changes in water heating technology by developing both tankless gas and hybrid electric water heater products the first to meet newly established Energy Star standards. Using solar energy to heat water for the home is the logical next step in the evolution of waters heaters."

The solar water heating industry is currently very small. Total deliveries in 2007 were only 12,000 units as compared with 9,000,000 of other types of water heaters, according to statistics from the Solar Rating & Certification Corporation, Rheem, and the Gas Appliance Manufacturer's Association. There are estimates that 17,000 solar water-heating units will be sold in 2008.

Solar water heaters typically consume between 50-70 percent less energy than a standard gas or electric tank water heater, according to GE, and are on average three times more efficient than comparable electric tank water heaters.

But are they more reliable and trouble free than their traditional counterparts? We'll see.