LG Heat Pump Error Code E341

E341 indicates a sump temperature digital sensor error in the outdoor unit, specifically an open or short circuit detected in the sensor or its wiring. The error is triggered when the outdoor temperature is above -10 degrees Celsius and the sensor voltage reads above 4.95V (suggesting an open circuit) or below 0.5V (suggesting a short circuit). The heat pump raises this fault because the sensor signal falls outside the valid temperature measurement range.

Continuing to operate the unit with an active E341 fault is not advisable. The sump temperature sensor helps protect the compressor and refrigerant system from running under unsafe conditions. Without a valid sensor reading, the control board cannot make accurate protective decisions, which could lead to compressor damage over time.

A power reset may temporarily clear the error code, but E341 will return if the underlying sensor or wiring fault is still present. The error is condition-based, meaning the control board will re-detect the out-of-range sensor voltage as soon as it checks the input again. A reset is useful for confirming whether the fault is intermittent, but it is not a repair and should be followed by proper diagnosis.

Some steps are accessible to a knowledgeable DIYer, including inspecting the sensor connector, reseating loose connections, and checking for visible wiring damage. Measuring sensor resistance with a multimeter is also straightforward if you are comfortable working around the outdoor unit with power off. However, replacing the sensor or control board requires sourcing the correct parts and comfort with disassembling the outdoor unit, so professional service is recommended if basic connector checks do not resolve the fault.

If only the sensor connector needs reseating or cleaning, there may be no parts cost at all, with a service call fee typically ranging from $75 to $150 depending on your area. Replacing the sump temperature sensor itself generally costs between $20 and $80 for the part, plus labor. If the control board requires replacement, total repair costs can range from $300 to $600 or more depending on the model and labor rates.