Bosch Water Heater Error Code EC

EC on a Bosch water heater indicates a gas leakage error caused by the gas valve circuit not closing properly. The control board has detected that it cannot confirm the gas valve is fully shutting off, so the unit locks out as a safety measure. This code requires inspection of the gas valve wiring and control board connectors before the unit can safely resume operation.

A simple reset may temporarily clear the EC code, but the error will return if the underlying cause has not been resolved. Because this code is tied to a safety-critical gas valve circuit, a reset without a proper diagnosis and repair is not a lasting or safe solution. The wiring connections and gas valve circuit should be inspected and confirmed secure before relying on the unit again.

Repair costs vary depending on the root cause. If the fix is simply reseating a loose connector, the cost may be limited to a service call fee, typically in the range of $75 to $150. If the gas valve needs replacement, parts and labor combined can range from $200 to $500 or more. A control board replacement generally falls in a similar or higher range depending on the model and labor rates in your area.

The EC code is a serious safety alert because it relates to the gas valve not closing as expected. The unit shuts itself down specifically to prevent uncontrolled gas flow. You should not attempt to override the lockout or bypass the error. Disconnect power, ventilate the area if you smell gas, and address the underlying wiring or component issue before restarting the unit.

Start by disconnecting the power supply cord completely. Then inspect all wire connections directly on the gas valve and trace both connectors to the control board, checking for loose, corroded, or damaged terminals. If the wiring is intact and secure, further testing of the gas valve solenoid and control board will be needed to identify which component is at fault. A qualified technician should handle gas valve replacement or control board evaluation.