State Water Heater E96 Error — What It Means
The E96 error code does not appear in State Water Heater diagnostic documentation. State water heaters (manufactured by A.O. Smith) use different fault codes for their electronic controls. This code is commonly associated with Baxi boilers, where it indicates a sensor fault or control board issue, but applying that definition to a State water heater would be incorrect. If you see E96 on your display, verify the brand and model on the unit’s data plate. You may have a Baxi boiler, an Intex spa controller, or another brand entirely. If the unit is confirmed to be a State water heater, consult the owner’s manual or wiring diagram for the correct error code list, as the display may show a different code or the control board may have been replaced with a non-original part.
Common Causes
- Wrong brand identification (~50%) The unit displaying E96 is actually a Baxi boiler or other brand that uses this code, not a State water heater.
- Non-original control board (~20%) A replacement control board from a different manufacturer was installed and uses a different error code system.
- Display misread (~15%) The code shown is actually a different number or letter combination that resembles E96.
- Wiring fault to display (~10%) Loose or corroded connections between the control board and display cause garbled error codes.
- Control board failure (~5%) The main electronic control has failed and is displaying an undefined or random code.
Quick Diagnosis
Answer these to narrow it down fast.
Does the data plate on the unit say State or A.O. Smith?
No: You may have a Baxi boiler or another brand. Look up the correct service manual for that brand.
Has the control board been replaced in the past?
No: Verify the exact characters on the display and cross-reference with the wiring diagram inside the service panel.
Does the manual list E96 in the troubleshooting section?
No: The code may be undefined or the display is faulty. A qualified technician should inspect the control board and wiring.
Step-by-Step Fix
- Verify the brand and model by reading the data plate on the water heater and comparing it to your manual.
- Locate the owner’s manual or download it from the State/A.O. Smith website using the model number.
- Check the error code table in the manual to see if E96 is listed and what it means for your specific model.
- Reset the control by switching off the circuit breaker for 30 seconds, then restoring power and observing if the code clears or returns.
- Inspect the display and control board for physical damage, moisture, or loose wiring connections at the terminals.
- Contact State customer service or a licensed plumber with gas and electric endorsements if the code is not documented or persists after reset.
- Do not attempt repairs on gas, high-voltage, or sealed water system components without proper training and tools.
Parts Often Needed
| Part | Notes |
|---|---|
| Electronic control board (State/A.O. Smith) | Amazon | Only if confirmed faulty by a technician and the unit is a genuine State water heater |
| Temperature sensor | Amazon | If the manual specifies E96 as a sensor fault for your model |
When to Call a Pro
Call a licensed plumber or water heater technician immediately if you cannot confirm the brand and model, if the error code is not listed in your manual, or if the unit involves gas or high-voltage components. Water heaters combine combustion, pressure vessels, and electrical controls, so misdiagnosis or improper repair can cause dangerous gas leaks, scalding, or fire. A qualified technician will verify the correct error code definition, test sensors and control boards with proper meters, and make sure all safety interlocks are functioning before restoring the unit to service.