York Error Codes | HVAC IQ Pro

1 Amber info

Normal - No Call for Heat

Probable Causes

Normal standby operation

Diagnostic Steps

No action needed - furnace is in standby

1 Red high

Lockout Retry / Recycle

Probable Causes

Ignition failure
Flame loss during run

Diagnostic Steps

Check gas supply
Clean flame sensor
Test igniter

2 Amber info

Normal - Call for Heat Active

Probable Causes

Normal heating operation

Diagnostic Steps

No action needed - furnace is heating

2 Red high

Pressure Switch Open

Probable Causes

Blocked vent
Inducer issue
Hose fault

Diagnostic Steps

Inspect flue
Check hose
Test inducer motor

3 Red high

Limit / Rollout Switch Open

Probable Causes

Dirty filter
Airflow restricted
Rollout trip

Diagnostic Steps

Replace filter FIRST
Check rollout switches
Inspect heat exchanger if rollout

4 Red high

Open Fuse / Loss of Flame

Probable Causes

Blown 3A fuse on board
Short in low voltage circuit

Diagnostic Steps

Check board fuse
Inspect low voltage wiring for shorts
Check thermostat connections

5 Red critical

Flame Without Gas Valve Call

Probable Causes

Leaking gas valve
Board malfunction

Diagnostic Steps

STOP - potential safety hazard
Turn off gas
Replace gas valve

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