DIY HVAC Tools

Lennox mini split code CP

Remote on/off contact open.

  • TypeStatus, not a fault
  • SystemDisplay
  • Can I fix it?Usually a homeowner fix
  • Applies toMCB / MWCB indoor unit display

What CP means on a Lennox

An external on/off contact (a remote switch, thermostat or card-key input wired to the indoor unit) has switched the unit off.

On this platform, CP is a status, not a fault: the unit is telling you what it is doing; nothing is wrong.

What to do

You can almost always clear this yourself with the steps below.

  1. Check any external switch or contact wired to the indoor unit.

When to call a technician

This is not a fault. No technician is needed unless it will not clear.

Which Lennox units show CP

This page applies to Lennox MPA / MPB / MLA single-zone, MPA / MPB / MLA multi-zone, MCB / MWCB, MWMA / MWMB, MCFA / MCFB and MMDA / MMDB units on the MCB / MWCB indoor unit display. Lennox's own documentation lists CP as "Remote on/off contact open", the same definition used across the Midea platform (four-character codes) it is built on. If your unit shows a code with a different shape (for example a four-character code, or a plain number), it is from a different table; use the lookup with your exact code.

Where Lennox shows this code

MCB / MWCB indoor unit display: The display shows a two-letter prefix and a two-character suffix, either together (EH60) or alternating (EH, then 60). Write both parts down; the suffix is what identifies the fault. EH and EL are indoor-side faults, EC is an outdoor-side fault, and PC is an outdoor protection: the unit stopped itself to prevent damage.

Other Lennox codes

Same part of the system as CP:

dFDefrost cycle runningCLFilter cleaning reminderAPWi-Fi pairing (access point) modeFPLow-temperature heating hold (46°F freeze-protection mode)FCForced cooling test modeLLRemote or wired controller lockedcFAnti-cold-air (heating warm-up)
E0Indoor unit EEPROM parameter error / Outdoor unit EEPROM parameter error (outdoor display)E1Communication error between indoor and outdoor unitsE2Zero-crossing signal detection error / Communication error between the outdoor unit and the indoor units (outdoor display)E3Indoor fan speed out of control (indoor fan motor fault) / Communication error between outdoor main board and IPM board (outdoor display)E4Indoor room temperature sensor (T1) open or short circuit / Outdoor temperature sensor fault: coil (T3), ambient (T4), discharge (T5) or a zone coil outlet (T2B)E5Evaporator coil temperature sensor (T2) open or short circuit / Over-voltage or under-voltage protection (outdoor display)ECRefrigerant leak detected (low refrigerant charge)F0Overload current protection (compressor over-current)

All Lennox error codes

CP on other brands

The same characters do not always mean the same thing. Check the brand on your unit.

Questions people ask

Is CP on a Lennox mini split an error?

No. CP is a status message: remote on/off contact open. An external on/off contact (a remote switch, thermostat or card-key input wired to the indoor unit) has switched the unit off.

Do I need a technician for Lennox CP?

You can almost always clear this yourself with the steps below. This is not a fault. No technician is needed unless it will not clear.

Sources

  • Lennox Corp1816-L7 Mini-Split Systems Service Manual: Indoor and Outdoor Unit Error Codes (MPA/MPB/MLA, MWMA, MCFA, MMDA), 10/2020
  • Lennox MCB / MWCB Mini-Split Service Manual (error code table 2.1)

Updated September 2026. Codes and definitions vary by model year. If your manual disagrees with this page, your manual wins. Send a correction.