Water Heater Flood Damage: What To Do After Your Unit Gets Wet

A water heater that has been under water should not be used, and the sources we read say it should be replaced. State Water Heaters’ electric manual says not to use the appliance if any part of it has been under water, because an electrical short or malfunction could occur, and that the water heater should be replaced. Its manual for gas tankless units is stronger still: contact a qualified installer or service agency to replace a flooded water heater, do not attempt to repair the unit, and it must be replaced. The U.S. Consumer Product Safety Commission (CPSC) adds the reason for the gas side.

What The CPSC Says About Gas Control Valves

The CPSC says gas control valves on water heaters that have been under water must be replaced. Its flood warning, issued in March 1997 and still on its website, says that even if these safety devices appear to function after being submerged they are unfit for continued use and cannot be repaired. Silt and corrosion from flood water can damage the internal components of control valves and prevent proper operation, and gas can leak and result in an explosion or fire. Such valves cannot be salvaged; they must be replaced.

The same warning says that other parts of gas and electric appliances that have been submerged, such as fans, motors, electric circuits and venting systems, should be evaluated by a qualified technician for continued safe operation, and that entire appliances may need to be replaced. It also says electric circuit breakers, ground fault circuit interrupters and fuses that have been submerged must be replaced. It is an older release, so check the CPSC site for anything newer.

What The Manuals Add

Both State manuals treat the appliance, not just the valve, as the thing to replace. The electric manual says the water heater should be replaced after any part has been under water. The gas tankless manual gives the same instruction in its start-up and water connection sections and says not to attempt repair. These are one manufacturer’s statements for its own products, and they match the CPSC’s direction that submerged safety devices are not repairable.

What Not To Do

• Do not operate the heater to see whether it still works; the CPSC says a safety device that appears to function after submersion is still unfit for use.
• Do not repair or relight it yourself. The gas manual says not to attempt repair, and the CPSC says submerged gas control valves cannot be repaired.
• Do not assume the circuit is safe. The CPSC says submerged breakers, GFCIs and fuses must be replaced.

If you smell gas at any point, leave first and use our emergency shut-off guide rather than anything here. Our emergency water heater repair page covers urgent calls, and water heater installation in Lancaster, PA covers the replacement.

What This Page Will Not Tell You

It will not tell you how to enter a flooded space, whether your home is in a flood area, or how to handle an insurance claim. The sources we read speak to the appliance, not to the building, and we hold no local flood-risk source, so we say nothing about any Lancaster-area neighborhood or river. We also give no replacement cost. For the broader replace-or-repair question once the unit is dry, see repair or replace.

Flood-Damaged Water Heater FAQ