Lennox Ducted Heating

Lennox Ducted Heating Error Code 4 Flashes

Ducted Heating

4 Flashes means different things on different Ducted Heating models. Enter your model number to see only your reading, or find your model below.

Check your model number (optional)

What It Means

ML196UHE: Low flame signal - check flame sensor
ML180UH: Primary limit switch open.
ML296UHV: Primary limit, secondarylLimit, or rollout switch open
G24M: Primary or Secondary Limit Open
G24M: Rollout Switch Open
LF24, TUA*S(N,L)(A,S)F: High limit or rollout switch open

Causes & actions from Lennox

Low flame signal - check flame sensor

Models: ML196UHE

How it shows

Integrated control red LED: 4 Flashes

This manual entry does not list further causes or actions.

Applicable models & manual sources

ML196UHE
Low flame signal – check flame sensor

ML196UHE manual, page 41

Primary limit switch open.

Models: ML180UH

How it shows

integrated control single led: 4 Flashes

This manual entry does not list further causes or actions.

Applicable models & manual sources

ML180UH
Primary limit switch open.

ML180UH manual, page 24

Primary limit, secondarylLimit, or rollout switch open

Models: ML296UHV

How it shows

Integrated control red LED: 4 Flashes

Primary limit, secondarylLimit, or rollout switch open

Applicable models & manual sources

ML296UHV
Primary limit, secondarylLimit, or roll- out switch open

ML296UHV manual, page 46

Primary or Secondary Limit Open

Models: G24M

How it shows

a3 diagnostic led: 4 Flashes

Combustion Air Blower: On Gas Valve: Off Supply Air Blower: On

Applicable models & manual sources

G24M
Primary or Sec- ondary Limit Open

G24M manual, page 12

Rollout Switch Open

Models: G24M

How it shows

a3 diagnostic led: 4 Flashes

Combustion Air Blower: On Gas Valve: Off Supply Air Blower: On

Applicable models & manual sources

G24M
Rollout Switch Open

G24M manual, page 12

High limit or rollout switch open

Models: LF24, TUA*S(N,L)(A,S)F

Unit heater (indoor)

How it shows

integrated control single led: 4 Flashes

This manual entry does not list further causes or actions.

Applicable models & manual sources

LF24
High limit or rollout switch open

LF24 manual, page 14
TUA*S(N,L)(A,S)F
High limit or rollout switch open

TUA*S(N,L)(A,S)F manual, page 17

Disclaimer: This information is for general reference. Code wording and instructions vary by model. Always follow the service manual for your exact unit.

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