The U.S. Consumer Product Safety Commission says Ritchie Industries of Conrad, Iowa, has begun the voluntary recall of its immersion heater models 17863, 17939, and 17940.

The outer cover of the device, which allows the heater to be placed in water, has cracked in at least 44 cases. The company says, in that situation, the heater poses a shock risk to users.

The heater is made by Springfield Wire of Springfield, Mass., and manufactured in the United States and Mexico.

Consumers should immediately stop using the recalled immersion heater and return it to the place of purchase for a free replacement heater.

Ritchie can be reached at (800) 747-0222.

Recall noticehttp://www.cpsc.gov/cpscpub/prerel/prhtml09/09141.html