QAS740RMSS F3 Error Code | Haier Range Fault Guide

Error F3 on Haier QAS740RMSS: Oven temperature sensor open circuit — sensor probe is disconnected or the inter. Follow the troubleshooting steps below to diagnose and fix this Range issue. ## What Is the F3 Error Code on the Haier QAS740RMSS? The F3 fault on the Haier QAS740RMSS — a 24-inch ENERGY STAR Electric Range with 2.9 cu. ft. convection oven, smoothtop radiant cooktop, steam clean, and modular backguard — means: Oven temperature sensor open circuit — sensor probe is disconnected or the internal resistance element has broken. The F3 fault code on Haier ranges means the oven temperature sensor circuit is open — the sensor is either physically disconnected, has a broken internal element, or the sensor wiring is broken. Without temperature feedback, the control board cannot regulate oven heat and enters a fault state. F3 is often a DIY-repairable fault: the sensor is an inexpensive part (typically ) mounted inside the oven cavity with 1-2 screws. > Severity: Medium — Experienced DIYers can often resolve this issue. --- ## Symptoms of the F3 Error When the F3 fault appears on your Haier QAS740RMSS: - Oven knob glows red when attempting to start baking or broiling

Oven will not preheat at all despite setting a temperature
Fault appears immediately when selecting any oven cooking mode
Oven cavity stays cold while knob is set to a cooking mode
SmartHQ app reports a sensor communication error --- ## Common Causes The F3 fault on the Haier QAS740RMSS is typically caused by: - Temperature sensor probe has burned out or its resistance element has broken internally
Sensor wiring harness connector has come loose from the control board or sensor plug
Sensor probe cracked or corroded from repeated high heat cycling
Sensor cable pinched by an oven rack or caught behind the rack support rail
Connector pins oxidized or corroded preventing electrical continuity --- ## Step-by-Step Troubleshooting | Step | Action | What to Do | Expected Result | |------|--------|-----------|----------------| | 1 | Disconnect power and locate the sensor | Unplug the range or turn off the circuit breaker. Open the oven door. The temperature sensor is a thin metal rod (about 2-3 inches long) at the upper rear corner of the oven cavity, held by 1-2 screws with a thin wire running through the back wall. | Sensor probe is visible and accessible from inside the oven | | 2 | Check the sensor connector | Trace the sensor wire behind the back panel and locate where it connects to the main harness. Confirm the connector is fully seated and the lock tab is engaged. A partially disconnected sensor is the most common cause of F3. | Sensor connector fully seated and lock tab is engaged | | 3 | Measure sensor resistance | Set a multimeter to ohms mode and measure resistance across the two sensor terminals. At room temperature (70°F/21°C) a good sensor reads approximately 1,080-1,100 ohms. An OL (open line) or infinite reading confirms a broken sensor that must be replaced. | Multimeter reads between 1,080-1,100 ohms for a good sensor | | 4 | Replace the temperature sensor | Remove the 1-2 mounting screws, gently pull the probe and wire through the oven back wall, disconnect the 2-pin connector, and install the new sensor in reverse order. Confirm the connector snaps securely before restoring power. | New sensor installed with connector fully engaged | | 5 | Verify repair by testing the oven | Restore power and set the oven to Bake at 350°F. The oven knob should glow orange as it preheats and the oven should reach temperature within 15-20 minutes. If F3 reappears, recheck the connector seating or test the replacement sensor resistance. | Oven preheats normally with no fault indicator | --- ## Frequently Asked Questions ### What causes the F3 error on a Haier range? F3 means the oven temperature sensor has an open circuit — the sensor probe is broken, disconnected, or has corroded wiring. The most common cause is a burned-out sensor element, which is an inexpensive part that homeowners can replace themselves. ### Can I use the cooktop when my Haier range shows F3? Yes — F3 is specific to the oven temperature sensor. The glass or gas cooktop surface burners operate independently from the oven sensor, so you can typically continue using the cooktop surface while the oven is in F3 fault mode. ### How do I test the oven temperature sensor on a Haier range? Disconnect the range from power, locate the sensor probe inside the oven on the back wall, and measure its resistance with a multimeter. A healthy sensor reads approximately 1,080-1,100 ohms at room temperature. An OL (infinity) reading confirms the sensor element is broken and requires replacement. ### Where can I buy a replacement oven sensor for my Haier QSS740RNSS or QAS740RMSS? Replacement temperature sensors are available from the Haier parts store at Haierappliances.com, authorized appliance parts dealers, and online retailers. Search using your exact model number to find the compatible sensor part number. ### Is F3 the same as F4 on a Haier range? No. F3 indicates the sensor circuit is open (infinite resistance — broken or disconnected). F4 means the sensor circuit is shorted (resistance dropped too low). Both are temperature sensor faults but the failure mode is opposite. A multimeter test distinguishes which code applies. --- ### Is it safe to keep using my Haier QAS740RMSS with error F3? If error F3 does not indicate an immediate safety hazard such as a gas leak, electrical short, or water flooding, you can continue limited use while monitoring the appliance. However, running the Range with an active error code increases the risk of further damage. Address the underlying issue as soon as possible. For high-severity errors, disconnect the appliance and contact a qualified technician. ### How much does it cost to fix error F3 on a Haier QAS740RMSS? Repair costs for error F3 on the Haier QAS740RMSS Range depend on the root cause. DIY fixes such as cleaning filters, resetting the unit, or reconnecting loose wires cost nothing beyond basic tools. If a component replacement is needed, parts and labor from a certified technician are the main expenses. Contact a Haier-authorized service provider for an accurate estimate based on your specific situation. ### What does error code F3 mean on a Haier Range? Error code F3 on Haier Range models indicates Oven temperature sensor open circuit — sensor probe is disconnected or the internal resistance eleme. This error is detected by the appliance’s internal diagnostic system and displayed to alert the user that attention is needed. Refer to the troubleshooting steps above for guidance on resolving this issue. ### Is it safe to keep using my Haier QAS740RMSS with error F3? If error F3 does not indicate an immediate safety hazard such as a gas leak, electrical short, or water flooding, you can continue limited use while monitoring the appliance. However, running the Range with an active error code increases the risk of further damage. Address the underlying issue as soon as possible. For high-severity errors, disconnect the appliance and contact a qualified technician. ### How much does it cost to fix error F3 on a Haier QAS740RMSS? Repair costs for error F3 on the Haier QAS740RMSS Range depend on the root cause. DIY fixes such as cleaning filters, resetting the unit, or reconnecting loose wires cost nothing beyond basic tools. If a component replacement is needed, parts and labor from a certified technician are the main expenses. Contact a Haier-authorized service provider for an accurate estimate based on your specific situation. ### What does error code F3 mean on a Haier Range? Error code F3 on Haier Range models indicates Oven temperature sensor open circuit — sensor probe is disconnected or the internal resistance eleme. This error is detected by the appliance’s internal diagnostic system and displayed to alert the user that attention is needed. Refer to the troubleshooting steps above for guidance on resolving this issue.

Need Professional Help? If the F3 error persists, contact Haier Customer Service: - Phone: 1-877-337-3639

Online: Haierappliances.com
Warranty: One-year limited warranty covers in-home service at no charge Last Updated: March 2026