Lennox Ducted Heating

Lennox Ducted Heating Error Code 2 Flashes

Ducted Heating

2 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

ML180UH, ML296UHV: Pressure switch closed with combustion air inducer de-energized.
ML196UHE: Improper earth ground
G24M: Loss of Flame Sensed (More Than 3 Trials for Ignition)
LF24: System lockout - failed to detect or sustain flame
TUA*S(N,L)(A,S)F: System lockout - failed to detect or sustain flame Current signal at FLAME terminal <0.6 microamps

Causes & actions from Lennox

Pressure switch closed with combustion air inducer de-energized.

Models: ML180UH, ML296UHV

How it shows

Integrated control red LED: 2 Flashes
integrated control single led: 2 Flashes

Pressure switch closed with combustion air inducer de-energized.

Applicable models & manual sources

ML180UH
Pressure switch closed with combustion air inducer de-en- ergized.

ML180UH manual, page 24
ML296UHV
Pressure switch closed with combus- tion air inducer de-energized.

ML296UHV manual, page 46

Improper earth ground

Models: ML196UHE

How it shows

Integrated control red LED: 2 Flashes

This manual entry does not list further causes or actions.

Applicable models & manual sources

ML196UHE
Improper earth ground

ML196UHE manual, page 41

Loss of Flame Sensed (More Than 3 Trials for Ignition)

Models: G24M

How it shows

a3 diagnostic led: 2 Flashes

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

Applicable models & manual sources

G24M
Loss of Flame Sensed (More Than 3 Trials for Ignition)

G24M manual, page 12

System lockout - failed to detect or sustain flame

Models: LF24

How it shows

integrated control single led: 2 Flashes

This manual entry does not list further causes or actions.

Applicable models & manual sources

LF24
System lockout − failed to detect or sustain flame

LF24 manual, page 14

System lockout - failed to detect or sustain flame Current signal at FLAME terminal <0.6 microamps

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

Unit heater (indoor)

How it shows

integrated control single led: 2 Flashes

This manual entry does not list further causes or actions.

Applicable models & manual sources

TUA*S(N,L)(A,S)F
System lockout - failed to detect or sustain flame Current signal at FLAME terminal <0.6 microamps

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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