mypros+
Error code reference

Dacor Oven Error Code L23

Lower oven ambient over temperature

Dacor codesDacor oven codes

Lower oven ambient over temperature - thermistor on relay board has registered over 80°C.

First step from the service manual

Verify exhaust area, inlet at bottom of door, and inlet grill are free from blockages.

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 L23.

  • 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 L23 means on a Dacor oven

The L23 error code on a Dacor oven indicates that the lower oven ambient temperature has exceeded 80°C (176°F) as measured by the thermistor located on the relay board. This thermistor monitors the ambient air temperature inside the oven cavity's control and component area, not the cooking temperature itself. When this threshold is crossed, the control system triggers the L23 fault to protect heat-sensitive electronics and relay board components from thermal damage.

The most common root cause of this condition is restricted airflow through the oven's ventilation pathways. The lower oven relies on a circulation system that draws cool air in through the inlet grill and the inlet at the bottom of the door, then exhausts heated air through the exhaust area at the rear or top of the unit. When any of these passages become blocked by debris, grease buildup, or improper installation clearances, heat accumulates in the component area and drives ambient temperatures above the 80°C limit.

Beyond simple blockages, a failing cooling fan motor can also cause insufficient airflow even when all vents are clear. If the fan is not moving adequate air volume across the relay board, the thermistor will detect rising ambient temperatures and trigger L23. In some cases, the thermistor itself or the relay board may be faulty, reporting incorrect temperature readings or failing to regulate properly. A thorough inspection of airflow paths should always be completed before suspecting component failure.

Source: manufacturer service documentation.

Common causes of L23

  1. 01

    Blocked exhaust area or inlet vents

    Wiring / connection

    Grease buildup, debris, or objects obstructing the exhaust area, bottom door inlet, or inlet grill restrict airflow and cause heat to build up around the relay board. Visually inspect all three ventilation points and clean any blockages before proceeding with further diagnosis.

  2. 02

    Improper installation clearances

    Wiring / connection

    If the oven was installed too close to cabinetry or adjacent surfaces, the exhaust air cannot dissipate properly and recirculates back into the inlet. Verify that all required clearances around the unit match the installation specifications.

  3. 03

    Cooling fan motor failure

    Part replacement

    A cooling fan that is running slowly or not at all will fail to move adequate air across the relay board even if all vents are clear. Listen for fan operation during a cycle and check for motor resistance or mechanical binding.

  4. 04

    Faulty relay board thermistor

    Part replacement

    The thermistor on the relay board may have drifted out of calibration or failed, causing it to report ambient temperatures above 80°C inaccurately. If airflow and the cooling fan check out normal, the thermistor or the relay board itself should be tested and replaced.

  5. 05

    Defective relay board

    Part replacement

    A relay board that is malfunctioning can generate excess heat internally or misinterpret thermistor signals, triggering L23 even under normal ambient conditions. This is typically diagnosed after ruling out airflow restrictions and a faulty thermistor.

See the test procedure for each cause

Frequently asked questions about L23

What does L23 mean on a Dacor oven?
L23 indicates that the lower oven ambient temperature has exceeded 80°C (176°F) as measured by the thermistor on the relay board. This is not the cooking temperature but rather the temperature of the air surrounding the internal electronic components. The fault is triggered to protect the relay board and other heat-sensitive parts from thermal damage. Restricted airflow is the most frequent cause of this condition.
How do I fix an L23 error on my Dacor oven?
Start by inspecting the exhaust area, the inlet at the bottom of the door, and the inlet grill for any blockages such as grease, debris, or foreign objects, and clear them completely. Also confirm that the oven has adequate clearance around it as required by the installation specifications. If the vents are clear and the error persists, the cooling fan motor, the relay board thermistor, and the relay board itself should be tested for proper operation. A qualified technician can perform resistance and voltage checks on these components to isolate the fault.
Is it safe to use my Dacor oven when the L23 code is showing?
It is not recommended to continue operating the oven while L23 is active. The fault indicates that temperatures around the relay board and electronics have reached a potentially damaging level. Continued use under this condition risks permanent damage to control components and could create a broader electrical failure. The oven should be left off until the cause of the overheating is identified and resolved.
Will resetting my Dacor oven clear the L23 error code?
A power reset by unplugging the oven or switching off the circuit breaker for a few minutes may temporarily clear the L23 code, but it will return if the underlying cause is not corrected. If the vent pathways are blocked or the cooling fan is not functioning, the ambient temperature will climb above 80°C again during the next use and trigger the fault again. Clearing the code without addressing the root cause does not resolve the problem.
How much does it cost to repair a Dacor oven with an L23 error?
If the fault is caused only by a blocked vent or inadequate clearance, the repair may cost nothing beyond your time to clean and inspect the unit. If a cooling fan motor needs replacement, parts and labor costs typically range from around $150 to $350 depending on the specific model and technician rates. A relay board replacement is generally more expensive, often falling in the range of $250 to $550 or more for parts and labor combined. Getting a diagnosis from a certified Dacor technician before purchasing parts is strongly recommended.

Related Dacor oven codes

All Dacor oven codes
View all 71 Dacor oven codes

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

Get Started

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