State Water Heater E123 Error Code — What It Means
E123 does not appear in State water heater documentation as a standard error code. State routes all troubleshooting through model-specific manuals and support resources rather than publishing a universal fault code list. The code you are seeing may be from a different brand, a misread display, or a model-specific code that requires the exact unit manual to interpret. Always start by locating the rating plate or QR code on your water heater and pulling the correct literature for your model from State’s support portal.
Common Causes
- Misidentified brand or equipment type E123 is documented for Samsung HVAC indoor evaporator sensor faults, not State water heaters, so you may be looking at the wrong appliance or confusing equipment.
- Display misread or partial code A blinking or scrolling display can be misread, and the actual code may be a different number that does appear in your model’s documentation.
- Model-specific code not in general literature Some State models use proprietary codes that only appear in the service manual shipped with that series, not in online summaries.
- Control board displaying a diagnostic test mode Certain State units show non-fault codes during self-test sequences that resemble error codes but clear after the cycle completes.
Step-by-Step Fix
- Locate the rating plate on the side or front of the water heater and write down the complete model number and serial number.
- Visit State’s support portal or scan the QR code on the rating plate to download the correct installation and service manual for your exact model.
- Check the troubleshooting section of that manual for a fault code table and confirm whether E123 or a similar code is listed.
- Power-cycle the unit by turning off the circuit breaker for two minutes, then restoring power to see if the code clears or changes to a recognized fault.
- Inspect the display panel for any other blinking lights, secondary codes, or status indicators that may clarify the fault condition.
- Contact State technical support through the phone number or chat link in your manual if the code does not match any published list, providing your full model and serial number.
- Call a licensed plumber or water heater technician if you cannot identify the code or if the manual directs you to professional service for that fault.
Parts Often Needed
| Part | Notes |
|---|---|
| Control board (model-specific) | Amazon | Only order after confirming the exact part number in your model’s service literature or through State support. |
| Display module (model-specific) | Amazon | If the display is damaged or showing garbled codes, verify compatibility by model and serial number before ordering. |
When to Call a Pro
Call a licensed plumber or water heater technician immediately if you cannot locate your model documentation, if the code persists after a power cycle, or if State support confirms the code requires hands-on diagnostics. Water heaters involve high-voltage electrical connections, gas lines, and pressurized hot water, so any repair beyond resetting the unit should be handled by a qualified professional. Always use State’s contractor locator or technical support line to find a service provider familiar with your specific model.