LCD Wiring Diagram Presentation

42-2111-1-B / 42-2111-2-B

PowerOff-OnSwitch

120V Power Supply

Power SwitchON

24 Volt Transformer

Powered

Low Operator

Call for Heat

Pump Relay

Energized

PumpContactCloses

PumpEnergizes

FlowSwitchMakes

FanManagerEnergizes

FanContactCloses

Fan Energizedon Low Speed

Low AirPressure

Switch Makes

Pre-purgeRelay

Energizes

Low PilotGas Valve &

R7 RelayEnergized

R7ContactMakes

SparkGeneratorEnergizes

Flame RodSensesPilot

Gas ValveEnergized

on Low

R7 Relay Drops Out Via R8 Relay

R8ContactMakes

Safety Solenoid

Energizes

R7 ContactDrops Out

Spark

High OperatorCalls Second Stage

High Speed Blower Relay

Energizes

BlowerRamps to High

Speed

High Pressure Air Switch Makes

High Fire Relay

Energizes

Gas Valve Energized on

High

Pilot Valve Energized on

High

Loss of Pilot

Flame

Retry After 5- Min. Wait

Flame Safeguard in 10- Min. Wait

Alarm Contacts Close R1 Energizes

Unit Failed to

Light

R1ContactBreaks

R1ContactMakes

Fan Manager Times Out

Fan Drops Out

PressureSwitches

Break

Alarm Contacts

Open

Pilot IgnitionRetry

Successful

High FireEstablished

Call for Heat

Drops Out

Blower Post Purge Times Out

Pump Purge Times Out

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