Lennox mini split error code PC 0F
PFC module malfunction. Also shown as PC0F.
- TypeProtection
- SystemPower supply
- Can I fix it?Technician job
- Applies toMCB / MWCB indoor unit display
What PC 0F means on a Lennox
The power-factor-correction stage that feeds the inverter reported a fault. Usually a board-level failure or a supply problem.
On this platform, PC 0F is a protection: the system stopped or throttled itself to prevent damage; many clear on their own once conditions return to normal.
Common causes
- Unstable supply voltage or a surge.
- A failed PFC module or outdoor main board.
- Overheating from a blocked coil or fan.
How to fix it yourself
Do the reset and the visual checks, but the underlying repair needs a technician with a meter and the service manual.
- Reset the system: switch the breaker (or the outdoor disconnect) off, wait a full five minutes so the boards fully discharge, then switch it back on and restart from the remote.
- If you own a multimeter and are comfortable using it, measure the supply voltage at the outdoor unit's L1 and L2 terminals with the unit running. A 230 V system should read roughly 208 to 253 VAC.
- Look at the outdoor unit: clear leaves, cottonwood fluff, snow or ice from the coil and make sure the fan can spin freely and nothing is stacked against the cabinet.
Switch off power at the breaker before opening either unit. Capacitors in the outdoor unit hold a charge for several minutes after power is cut.
When to call a technician
A technician needs to check the PFC stage and DC bus; usually a board replacement.
Which Lennox units show PC 0F
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 PC 0F as "PFC module malfunction", 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 PC 0F:
PC 0F on other brands
The same characters do not always mean the same thing. Check the brand on your unit.
- Pioneer PC 0F PFC module malfunction
Questions people ask
Can I reset a Lennox PC 0F code myself?
Yes. Turn the system off at the breaker for five minutes, then restart it. If PC 0F comes back, the fault is real and needs the checks above.
Is it safe to keep running a Lennox showing PC 0F?
Not repeatedly. A protection code means the unit stopped itself to prevent damage, and resetting it over and over can turn a cheap repair into a compressor failure. Reset once, check the basics, and stop if it returns.
What will a technician check for PC 0F?
A technician needs to check the PFC stage and DC bus; usually a board replacement. Ask for the measurements, not just a parts quote.
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.