Aqua Grate fireplace-powered water heaters

What's the hazard

November 18, 1982Release #82-049 CPSC Warns Of Explosion Hazard with Fireplace-Powered Water Heaters Washington, D.C. - The U.S. Consumer Product Safety Commission today warned consumers of an explosion hazard with certain fireplace-powered water heaters used to supplement home heating systems. Units involved were sold under the brand names "Hydrohearth," "Hydroplace," and "Aqua Grate." Manufacturers of these units - Ridgeway Steel Fabricators, Inc. of Ridgeway, Pennsylvania and Shark Manufacturing Corporation of Greenlawn, New York are no linger in business. These devices are made of tubular steel or steel plate and resemble a fireplace grate or liner. Plumbing connects the unit to the hot-water heating system of the home. When these is a fire in the fireplace, furnace heat is either supplemented or replaced entirely by heat generated through the fireplace. Slowing or stopping the flow of water through the unit (resulting from circulator pump failure, electrical power failure, or frozen pipes) may result in water in the unit boiling into steam. If the unit does not have an adequate pressure relief device, properly installed, the build-up of pressure can cause an explosion. CPSC urges consumers who have one of these units to have its installation checked by a qualified, licensed plumber who has specific knowledge of boilers, water pumps, pipe freezing problems, and pressure relief valves. Of particular importance is the location, pressure rating, and flow capacity of the safety valve. If there is no safety valve, have one installed with a pressure rating and flow capacity suitable for any type of fire. The safety valve should be installed in the outlet piping as near to the unit as possible without risking damage due to overheating. It should be oriented according to the valve manufacturer's recommendation to avoid safety valve clogging. The outlet pipe from the unit to the safety valve should contain no valves or other restrictions. The safety valve should be checked periodically by triggering it to be sure that it will relieve pressure. This should be done with caution, by a knowledgeable person, to avoid hot water scalding. Other fireplace-powered water heaters that contain built-in safety devices such as burst disks, fusible plugs, or blowout plugs, are not subject to this warning. Information on the devices involved and what owners of these devices should do can be obtained by calling the Commission's toll-free Hotline at 800-638-CPSC