EC11 or Error Code 11
An 11 error code is an ignition failure. In other words, the unit recognizes there is a demand for hot water but for some reason is not able to ignite. This usually means there is no spark or insufficient gas entering the burner for ignition. In some cases the 11 error code could also occur when when the unit ignites but fails to detect ignition via the flame rod.
The first step in troubleshooting is using the small sight glass built into the burner to observe if the burner is actually failing to ignite or failing to detect ignition.
Common issues related to an ignition failure are:
1) insufficient gas supply
2) insufficient air flow
3) debris on the ignition plug
It is recommended that you contact a servicer to troubleshoot this error code
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