Discharge Pipe Temperature Sensor Error

What it means

This code appears on LG inverter split air conditioners and on LG ducted and cassette units that use CH codes. It means the thermistor on the compressor discharge pipe in the outdoor unit is giving an impossible reading because of an open or short circuit. This sensor protects the compressor from overheating, so the unit stops the compressor until it is fixed. The same code can mean something else on other brands.

Models covered: LG inverter split air conditioners (e.g. Dual Inverter) and LG ducted/cassette units that use CH codes; the code shows as CH plus a number on the display or as LED blinks.

Related codes: CH32CH44CH45CH46

Symptoms3

• CH41 shows and the compressor stops while the indoor fan may keep running.
• The code appears right after start-up or once the compressor warms up.
• The fault may be intermittent as the outdoor unit vibrates.

Possible causes5

• Loose or corroded sensor connector on the outdoor PCB.
• Sensor worn out by the high discharge pipe temperature over the years.
• Sensor wire melted or cut from touching the hot pipe or rubbing on the casing.
• Dirt, water or insects inside the outdoor unit electrical box.
• Faulty sensor input on the outdoor PCB.

How to diagnose5

1. Switch off the breaker for a few minutes, then restart.
2. After switch-off, the technician waits for the board to discharge, then checks the sensor on the discharge pipe and its wire up to the connector.
3. Unplug the sensor and measure its resistance against the LG resistance-temperature table.
4. Confirm the plug is clean and in its correct socket.
5. If the sensor is good, check the sensor input on the outdoor PCB.

How to fix5

1. Clean and reseat the sensor connector.
2. Repair the wire, route it away from the hot pipe and secure it with ties.
3. Replace the discharge pipe sensor (sometimes supplied as an outdoor sensor set).
4. Replace the outdoor PCB if its sensor input is faulty.
5. Run the unit long enough for the compressor to heat up and confirm the code stays away.

Repair cost

In Saudi riyals; the highlighted part is the expected range for this fault.

Most cases are a sensor or sensor set at low cost; the top of the range is the rare case needing a new outdoor PCB.

Prices are rough estimates including the part and the technician’s fee, and vary with brand, model and part source.
Prices last updated: September 2026

Frequently asked questions