The tankless water heater, that vaunted energy-saving appliance, apparently doesn't like the cold.

Any number of Lowcountry residents called plumbers in the past week as temperatures plummeted and the plumbing, um, didn't.

"We basically have had all four phones ringing off the hook. We're getting four and five messages a minute," said Terry Delk of Delk Plumbing.

It's not just tankless water heaters, it's anything with an exposed pipe, he said. But tankless heaters are somewhat more susceptible to pipes freezing simply because they are more often kept outdoors.

"Just as a rule of thumb, any potable water exposed to the elements is at risk," he said.

Pipes for tankless heaters must be wrapped with a heat tape and insulated, according to the Rinnai tankless water heater website.

The company also recommends a draining system in cold climates in case the heater's power source fails.

Insulating the pipes certainly helps, Delk said. He also recommends and installs a freeze protection kit and shut-off solenoid valve.

The bottom line is to shelter or protect the heaters from cold as much as possible.

"Nothing is 100 percent (foolproof)," Delk said.

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