Thermador Refrigerator Error Code 3-1-5

Code 3-1-5 indicates a problem with the icemaker inlet water heater. This heater prevents the icemaker water inlet from freezing during operation. The control board has detected an abnormal condition in the heater circuit and has flagged the fault to alert you that service is needed. The icemaker may stop functioning until the issue is corrected.

A reset may temporarily clear the fault code from the display, but it will not fix the underlying problem. If the inlet water heater or icemaker module is defective, the code will return once the control board runs its diagnostic cycle again. The root cause must be diagnosed and repaired for the code to stay cleared.

Repair costs vary depending on what component has failed. If only the inlet water heater element needs replacement, parts and labor typically range from around $100 to $250. If the full icemaker assembly requires replacement, costs generally range from $200 to $500 or more depending on the specific model and local labor rates. Getting a diagnostic assessment from a qualified technician before ordering parts is always advisable.

Start by measuring the resistance of the inlet water heater: the correct value is 7 kilohms for US models and 33 kilohms for EU models. If the resistance is out of range, the heater element needs to be replaced. If the resistance is within spec, the icemaker assembly itself is the likely culprit and should be replaced. Also inspect the wiring harness and connectors for damage or corrosion before replacing any parts.

This fault is not a safety hazard in the traditional sense, but it does mean your icemaker is not operating correctly and may not produce ice. Leaving the issue unaddressed could eventually allow the water inlet to freeze, which might cause water supply problems or damage to nearby components over time. Prompt diagnosis is recommended.