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Error code reference

Dacor Range Oven Cooktop Error Code U55

Latch/door (upper/single oven)

Dacor codesDacor range oven cooktop codes

Latch/door (upper/single oven) - bad latch motor or bad relay board.

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Get the full diagnostic procedure for U55.

  • 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
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What U55 means on a Dacor range oven cooktop

Error code U55 on Dacor ranges and ovens indicates a fault in the door latch system for the upper or single oven cavity. This code is specifically tied to the motorized latch assembly used during self-clean cycles, when the oven door must lock securely before high-heat operation can proceed. The control system monitors the latch motor and its associated relay board for correct operation. When it detects a failure in either component, it triggers U55 and halts or prevents the self-clean function.

The two primary components flagged by U55 are the latch motor itself and the relay board that controls power delivery to that motor. The latch motor is a small electric motor that drives the locking mechanism to engage and disengage the door lock. The relay board acts as the switching interface between the main control board and the latch motor. A failure in either component breaks the circuit or signal path required for the control system to confirm a successful latch operation.

Common causes include a burned-out or mechanically seized latch motor, a failed relay on the relay board, wiring harness damage between the relay board and the latch assembly, or carbon buildup from previous self-clean cycles jamming the latch mechanism. In some cases, the relay board itself may have a faulty solder joint or a relay that has welded closed or open due to electrical stress. Diagnosing the root cause requires checking motor continuity, inspecting the relay board for visible damage, and verifying that voltage is being delivered correctly through the circuit.

Source: manufacturer service documentation.

Common causes of U55

  1. 01

    Faulty latch motor

    Part replacement

    The latch motor may be burned out, have an open winding, or be mechanically seized from heat exposure or carbon buildup. Checking the motor for continuity and free mechanical movement will help identify this failure.

  2. 02

    Failed relay board

    Part replacement

    A relay on the relay board may have failed open or closed, cutting off proper power delivery to the latch motor. Visible burn marks, discoloration, or a failed relay component on the board are indicators of this problem.

  3. 03

    Wiring harness damage

    Wiring / connection

    The wiring between the relay board and the latch motor assembly can suffer from heat damage, fraying, or loose connectors. Inspecting the harness for continuity and secure connections is an important diagnostic step.

  4. 04

    Jammed latch mechanism

    Wiring / connection

    Debris, carbon residue from prior self-clean cycles, or a warped latch arm can physically prevent the motor from completing its travel. Inspecting and cleaning the latch assembly may resolve the issue without replacing electrical components.

  5. 05

    Main control board communication fault

    Part replacement

    If the main control board is not sending the correct signal to the relay board, the latch motor will never activate. This is a less common cause but should be considered after the latch motor and relay board have been ruled out.

See the test procedure for each cause

Frequently asked questions about U55

What does U55 mean on a Dacor range, oven, cooktop?
U55 indicates a fault in the door latch system of the upper or single oven cavity. The code points to a problem with either the latch motor, which physically moves the door lock, or the relay board that controls power to that motor. The oven triggers this code when it cannot confirm a successful latch operation, typically during or before a self-clean cycle.
Can I fix the U55 error myself?
Some causes of U55, such as a jammed latch mechanism or a loose wiring connector, can be addressed without replacing parts. However, replacing the latch motor or relay board requires working near high-voltage components and a solid understanding of appliance repair. If you are not comfortable with electrical diagnostics, a qualified technician is the safer choice.
Is it safe to use my Dacor oven while the U55 code is active?
Basic baking and cooking functions may still work depending on how the failure has manifested, but the self-clean cycle should not be attempted while U55 is active. A non-functioning door latch is a safety concern specifically for self-clean operation, which requires the door to be securely locked during extreme heat. Resolve the latch fault before running any self-clean cycle.
Will resetting the oven clear the U55 error code?
A power reset by turning off the circuit breaker for one to two minutes may temporarily clear the code, but it will return if the underlying hardware fault is still present. U55 reflects a real component failure in the latch motor or relay board, so a reset alone is not a repair. The fault must be diagnosed and the defective part replaced to permanently clear the code.
How much does it cost to repair a Dacor U55 error?
Repair costs vary depending on which component has failed. A latch motor replacement typically falls in the range of $75 to $200 for the part alone, while a relay board can range from $100 to $300 or more depending on the model. Adding professional labor costs, total repair estimates generally range from $150 to $500. Getting a diagnostic quote from a technician before committing to repairs is recommended.

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