mypros+
Error code reference

Bosch Refrigerator Error Code 3-1-5

Ice maker

Bosch codesBosch refrigerator codes

Ice maker: Icemaker inlet water heater problem.

First step from the service manual

Check resistance of inlet water heater (US: 7kOhm, EU: 33kOhm); if OK replace ice maker.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

MyPros+ Max

Get the full diagnostic procedure for 3-1-5.

  • Step-by-step tests with expected resistance, voltage, and continuity values
  • Wiring diagram references and connector pinouts from the OEM service manual
  • Verified part numbers when replacement is required
Get the full procedure

$29/month · Cancel anytime · Or $9.95 3-day pass

What 3-1-5 means on a Bosch refrigerator

Error code 3-1-5 on a Bosch refrigerator indicates a problem with the ice maker inlet water heater. This small resistive heater is built into the ice maker's water inlet assembly and is responsible for preventing the inlet valve and water line connection from freezing. The control board monitors this heater circuit and triggers the 3-1-5 code when it detects a fault, which can mean an open circuit, a short, or a resistance value that falls outside the acceptable range.

The primary diagnostic step is measuring the resistance of the inlet water heater directly at the component. For US-market units, the correct resistance is approximately 7 kOhm. For EU-market units, the target resistance is approximately 33 kOhm. A reading that is significantly higher, lower, or shows no continuity at all indicates the heater element has failed and the ice maker assembly will need to be replaced. If the resistance reads within the correct range, the fault may lie in the wiring harness or the control board connection rather than the heater itself.

Because the inlet water heater is typically integrated into the ice maker unit rather than sold as a standalone part, a confirmed heater failure usually means replacing the entire ice maker assembly. Wiring issues such as a pinched harness, corroded connector terminals, or a broken wire between the control board and the heater can also produce this code even when the heater element itself tests correctly. Always inspect the connector and harness continuity before condemning the ice maker assembly.

Source: manufacturer service documentation.

Common causes of 3-1-5

  1. 01

    Failed inlet water heater element

    Part replacement

    The resistive heating element inside the ice maker's water inlet has burned out or gone open circuit. This is confirmed by measuring resistance at the heater: US units should read approximately 7 kOhm and EU units approximately 33 kOhm. A reading far outside these values or no continuity confirms element failure.

  2. 02

    Corroded or damaged wiring connector

    Wiring / connection

    Moisture inside the freezer compartment can corrode the connector terminals between the wiring harness and the inlet water heater. Inspect the connector for green or white oxidation, bent pins, or loose fit, which can cause intermittent or complete circuit faults even when the heater itself tests correctly.

  3. 03

    Broken or pinched wiring harness

    Wiring / connection

    The wiring leading to the inlet water heater can be pinched by ice buildup or damaged during prior service. Check the harness routing from the control board to the ice maker for any visible cuts, abrasion, or areas where the wire has been compressed against a sharp edge.

  4. 04

    Ice maker assembly internal fault

    Part replacement

    If the heater resistance is within spec and the wiring and connectors are intact, the fault may be internal to the ice maker module itself, such as a failed internal connection. In this scenario the entire ice maker assembly requires replacement.

See the test procedure for each cause

Frequently asked questions about 3-1-5

What does 3-1-5 mean on a Bosch refrigerator?
Error code 3-1-5 on a Bosch refrigerator indicates a problem with the ice maker's inlet water heater circuit. This heater prevents the water inlet from freezing during the ice-making cycle. The control board detected that the heater's electrical characteristics are outside the expected range, which prevents the ice maker from operating safely. The first step is measuring the heater's resistance: 7 kOhm for US models or 33 kOhm for EU models.
Can I fix error code 3-1-5 myself?
A knowledgeable DIYer with a multimeter can perform the key diagnostic step, which is checking the resistance of the inlet water heater and inspecting the wiring and connector. If the heater tests bad, the repair involves replacing the ice maker assembly, which requires disconnecting water and electrical connections inside the freezer. If you are comfortable working with appliance components, this is a feasible DIY repair, but if you are unsure about electrical testing or component replacement, hiring a technician is the safer choice.
Is it safe to use my Bosch refrigerator while error code 3-1-5 is active?
The refrigerator's cooling and food preservation functions will generally continue to operate with this error code active, so your food should not be at immediate risk. However, the ice maker itself may stop producing ice or operate unreliably until the fault is resolved. It is best to address the repair promptly to prevent any secondary issues from a non-functional inlet heater, such as a frozen water inlet line.
How much does it cost to repair error code 3-1-5 on a Bosch refrigerator?
If only a wiring connector needs cleaning or repair, costs can be minimal, typically just a small amount for connector terminals or supplies. If the ice maker assembly itself needs replacement, parts alone can range from roughly 80 to 250 dollars depending on the model, and professional labor adds another 100 to 200 dollars or more. Getting a diagnosis from a technician before ordering parts is advisable to confirm whether the heater, wiring, or full assembly is at fault.
Will resetting my Bosch refrigerator clear error code 3-1-5?
Resetting the refrigerator by unplugging it briefly may temporarily clear the code from the display, but the code will return if the underlying fault with the inlet water heater circuit has not been repaired. A reset does not fix a failed heater element or damaged wiring. The correct approach is to diagnose and repair the root cause before expecting the code to stay clear.

Related Bosch refrigerator codes

All Bosch refrigerator codes
View all 209 Bosch refrigerator codes

78,000+ service manuals · 160,000+ error codes · 55+ brands

Get Started

$29/month · Cancel anytime · Or $9.95 3-day pass