Deactivating an Erroneous Low‑Temp Cutoff on the Electrolux EHF1500 Electric Heater

Understanding the Low‑Temp Cutoff Feature

The Electrolux EHF1500 electric heater is equipped with a built‑in low‑temp cutoff (LTC) that protects the heating element and prevents the unit from operating in dangerously cold conditions. Under normal circumstances the LTC engages when the ambient temperature drops below the preset safety threshold and automatically shuts the heater off. In rare cases a sensor fault or an inadvertent setting can cause the LTC to trigger even when the room temperature is well above the limit. This guide explains how to diagnose the problem and safely deactivate an erroneous LTC without compromising the overall safety of the heater.

Why Deactivating the LTC May Be Necessary

• False readings: A malfunctioning temperature sensor can send a low‑temp signal to the control board even though the room is warm.
• Improper installation: If the heater is placed in a location where the sensor is exposed to drafts or cold surfaces, the LTC may activate prematurely.
• User preference: Some users operate the heater in a well‑insulated space where they are comfortable keeping the LTC disabled for continuous heating.

Before proceeding, be aware that turning off the LTC removes a safety layer. Only continue if you have verified that the heater’s environment is safe and the unit is in good working order.

Tools and Materials Required

• Phillips head screwdriver (size #2)
• Flat‑head screwdriver (optional)
• Multimeter with temperature probe function
• Small flashlight or headlamp
• Protective gloves
• Safety glasses
• Service manual for the Electrolux EHF1500 (if available)

Safety Precautions

• Unplug the heater from the wall outlet before opening any panels.
• Verify that the power switch is in the OFF position.
• Wear protective gloves and safety glasses to guard against sharp edges and accidental contact with electrical components.
• Keep a fire extinguisher rated for electrical fires nearby.
• Do not attempt this procedure if you are uncomfortable working with electricity; contact a qualified technician instead.

Step‑by‑Step Procedure

Locate the Control Panel

1. Place the heater on a stable surface with enough clearance around it.
2. Using the Phillips screwdriver, remove the two screws that secure the front cover.
3. Gently lift the cover away from the body of the heater. The internal components, including the control board and temperature sensor, will be visible.

Identify the Low‑Temp Cutoff Sensor

• The LTC sensor is typically a small metal probe inserted into the heater’s housing near the heating element. It may be labeled “LTC” or “TEMP SENSE” on the circuit board.
• Follow the sensor’s wiring back to the control board where it connects to a two‑pin header.

Test the Sensor for Accuracy

1. Set the multimeter to the resistance (Ω) mode with temperature probe capability.
2. Disconnect the sensor’s connector from the control board.
3. Attach the multimeter probes to the sensor leads.
4. Compare the reading to the values listed in the service manual for a normal temperature range (typically around 10 kΩ at 20 °C).

• If the reading is within the expected range, the sensor is likely functioning correctly and the false LTC activation could be due to a wiring issue or a software glitch.
• If the reading is significantly higher or lower, the sensor is defective and should be replaced rather than bypassed.

Bypass the Sensor (If the Sensor Is Confirmed Functional)

Important: Bypassing the sensor removes the LTC safety feature. Perform this step only after careful consideration.

1. Locate the two‑pin header on the control board where the sensor connects.
2. Using a small piece of insulated wire (about 1 inch long), create a jumper that connects the two pins together.
3. Secure the jumper with a tiny dab of non‑conductive epoxy or heat‑shrink tubing to prevent accidental short circuits.
4. Re‑attach the sensor’s connector to the board, leaving the jumper in place.

Reassemble the Heater

1. Replace the front cover and align the screw holes.
2. Tighten the two screws with the Phillips screwdriver, being careful not to strip the threads.
3. Ensure that no wires are pinched and that the cover sits flush against the heater body.

Verify Operation

1. Plug the heater back into a grounded outlet.
2. Turn the power switch to ON and set the desired temperature using the thermostat dial.
3. Allow the heater to run for at least ten minutes while monitoring the display and listening for any abnormal sounds.
4. Use the multimeter’s temperature probe (if available) to check the ambient temperature near the heater. Confirm that the unit remains on even when the temperature is below the original LTC threshold.

If the heater operates continuously without shutting off, the bypass has been successful. If the heater still powers down unexpectedly, revisit the sensor testing step or consider that the control board itself may be misinterpreting temperature data. In such cases, consult a qualified service technician.

Optional: Re‑Enable the Low‑Temp Cutoff

Should you decide to restore the original safety feature, simply remove the jumper wire and reconnect the sensor’s wiring as it was originally configured. Re‑assemble the heater and verify that the LTC engages at the designated low‑temp point.

Troubleshooting Common Issues

When to Seek Professional Help

• The heater shows signs of internal damage such as scorched wires or melted plastic.
• You are unable to locate the sensor or the control board due to model variations.
• The multimeter readings are inconsistent or the sensor appears intact but the heater still behaves erratically.
• You feel uncertain about any step involving electrical connections.

A certified appliance repair technician can perform a deeper diagnostic, replace faulty components, and ensure that the heater complies with local safety regulations.

Maintenance Tips to Prevent Future Low‑Temp Cutoff Issues

• Keep the heater on a flat, stable surface away from drafts, windows, or direct sunlight.
• Clean the exterior fins and vents regularly with a soft brush to maintain proper airflow.
• Inspect the temperature sensor and its wiring annually for signs of corrosion or wear.
• Avoid covering the heater with blankets, clothing, or furniture while it is operating.
• Follow the manufacturer’s recommended service intervals for internal cleaning and component checks.

Summary

The Electrolux EHF1500 electric heater’s low‑temp cutoff is a valuable safety mechanism, but a malfunctioning sensor or unsuitable installation can cause it to engage erroneously. By carefully testing the sensor, creating a safe jumper to bypass the LTC, and thoroughly verifying the heater’s operation, you can restore continuous heating in environments where the cutoff is unnecessary. Always prioritize safety: disconnect power before working on the unit, wear protective gear, and consider professional assistance when the problem extends beyond the sensor itself. Proper maintenance and mindful placement of the heater will reduce the likelihood of future LTC issues and keep your heating experience reliable and comfortable.