It's 7 a.m. You crawl out of bed dreaming of a hot shower before going to work to compensate for a cold house due to the limitations of your heating system to raise temperatures by more than seven degrees above the freezing temperatures outside. Opening the back door to let out the dog, you hear water cascading off the roof. There isn't a cloud in the sky. During mid-January, untold householders faced this very scenario or a similar one - left to shell out a minimum of NIS 2,000 after their solar collectors that normally provide free hot water burst in sub-zero temperatures. Particularly hard-hit have been the Shfela (the southern foothills running from Rehovot to Gedera and Kiryat Gat) and the Negev Plateau. In rural communities like Kfar Warburg, entire streets lost their collectors; in Yeroham, 1,000 of the 2,500 households - including those of Mayor Amram Mitzna and his staff - were hit. Service warranties of major manufacturers like Amcor exempt themselves from being slapped with thousands of claims with an escape clause that regards such occurrences as an act of God, an unforeseen event beyond the party's control, such as an earthquake or volcanic eruption. But can frost rationally be construed as unforeseen? Or are we perhaps dealing here with a faulty product with a built-in self-destruct mechanism, a bug that serves as a periodic bonanza for manufactures and installers? New collectors are no less vulnerable than a pair of 15-year-old ones, and many of the new ones are even more vulnerable. Burst panels have nothing to do with age or metal fatigue, only basic physics in the transfer from a liquid to a solid state, explained an employee at Amcor's technical division. Those who have spanking new solar panels, installed last week, have an equal chance of them bursting tomorrow if temperatures again drop to below zero. That's exactly what happened to Yaffa and Shalom Dadon in Yeroham. Not once, but twice: "We replaced the panels twice this week, one after the other... and twice in a frost last year, too," said Yaffa. "Our panels have burst in the winter three times in 10 years. Leaving the boiler on at night and leaving a tap trickling doesn't help at all. My home insurance only paid once." All the more ironic, while some older metal panels have plastic safety caps that blow before a panel freezes, the freezing pattern of new, superefficient, all-copper coil panels make this simple gadget inapplicable, rendering the most efficient panels the most vulnerable to frost. The Internet shows that elsewhere solar heaters for single-family use are mostly equipped as a matter of course with frost protection mechanisms - even in other Mediterranean countries like Greece. Passive solar heaters, common in Israel, depend solely on physics, hot water rising to the top of collectors to fill the storage tank. Elsewhere, frost protection ranges from pumps that keep water circulating or external heat transfer units parallel to the panel that sense low temperatures and reverse the flow, sending water from the storage tank into the collector before it freezes. Some make collectors of special materials that can withstand the expansion of ice; others have anti-freeze Glycol parallel to water pipes. Some are equipped with an elastic displacement bladder-like device that absorbs the space of expanding ice. And here? Zilch. Israel may be the mother of solar heating. It may be an unrivaled superpower in terms of per capita usage: 95 percent of all households. But in terms of design? Solar heaters here haven't changed since the 1950s! We're talking about single-family units, not new high-rise buildings where collective collectors with pumps are an architectural element. They sometimes even swivel with the sun. MIKI BENOWITZ, a solar water heater installer from Katzrin, says many rural communities on the Golan Heights simply let their solar heaters hibernate during the worst of the winter months. Benowitz installs three simple water taps that allow homeowners to disengage and drain the collector, leaving the electric boiler to heat water in the winter. Amcor offers no such option, nor any other solution. Yeroham's spokesman Rafi Pahima says countless residents are busy adopting this strategy in the South. This retro-fit solution, while neither ideal nor practical in most circumstances, nevertheless remains one of the best-kept secrets in the solar water heater business. Engineers will argue that all products are designed for reasonable use. The Ayalon Freeway's drainage capacity couldn't handle the exceptionally heavy rain that turned it into a canal in 1991 - twice. Prof. David Faiman, head of Ben-Gurion University's National Solar Energy Center in Sde Boker (where 14 collectors burst), will tell you it boils down to cost-benefit. Passive solar heaters are cheap - around NIS 3,500 including the boiler. Solar units abroad are much more expensive and can run $2,500 in Canada, partially due to all the add-ons that make them operational in less temperate climates. In places like Austin, Texas, one is required to have frost-protection to be eligible for tax rebates. The key question is how unseasonable is frost? It isn't. Ask the Israel Meteorological Service. Avner Furshpan, director of the Climate Domain of the Meteorological Center in Beit Dagan, says extended periods like this are rare, describing the present cold front as "extreme and unusual" - perhaps once every decade. But he adds that there have been briefer periods with similar or even lower temperatures recorded in 1972/3, 1984, 1989, 1992, 1997 and 2004. If frost was once rare, since 1984 somewhere in Israel there are communities paying a penalty for badly designed panels every three to five years. Talia Horwitz, head of the agricultural meteorology department, adds: "There is frost at least once or twice a year to one degree or another everywhere in Israel, except the Coastal Plain and around the Kinneret and Dead Sea." The effect hinges on whether it last just a half an hour at 3 a.m., which is common, or lasts for several hours. Particularly vulnerable are the Hula and Jezreel valleys, the Shfela and the Negev Plateau. In frost-prone Kfar Blum, temperatures plummeted to minus 4.3Âº and in frost-prone Sde Boker to minus 4.5Âº, but even in Mazkeret Batya, where Horwitz resides, solar units burst. CONSIDERING THAT one cold night with two hours of subzero temperatures can total your solar panels, it's not out of line to suggest solar heaters should be equipped with frost protection. Manufacturers seem to be acting like Charlie Chaplin in that unforgettable silent movie scene of a glazier drumming up business by sending his sidekick kid ahead of him to break windows. One source in Gedera reported that the installer hiked collector panel prices from NIS 1,600 the morning after the first frost to NIS 2,400 the same afternoon, claiming the supplier of collector panels had raised the price. Someone is clearly making a killing off a helpless public. Reuven Godali, head of the energy division of the Israel Standards Institute, said standards abroad don't require frost-protection and neither do Israel's, but there is a non-obligatory standard for frost-protection (No. 579-4); that is, if a product claims to provide frost protection, they test its performance. Godali said he will raise reexamination of frost protection at the institute's Standards Committee. The committee is comprised of experts, consumer rights people and manufacturers, but anyone - including members of the public - can appeal to the committee if they feel a standard is flawed.