Auer Steel
Skip to main content
Site Search
submit search
Products
Boilers
Commercial Boilers
Com Hot Water Condens Domestic Boilers
Com Hot Water Condens Fire Tube Boilers
Com Hot Water Condens Water Tube Boilers
Commercial Cast Iron Boilers
OEM Boiler Parts
Residential Boilers
Electric Boilers
Res Condensing Fire Tube Combi Boilers
Res Condensing Water Tube Combi Boilers
Res Hot Water Cast Iron Grav Vent Boiler
Res Hot Water Cast Iron Oil Boilers
Res Hot Water Cast Iron Powr Vent Boiler
Res Hot Water Cast Iron Seal Comb Boiler
Res Hot Water Condens Fire Tube Boilers
Res Hot Water Condens Water Tube Boilers
Res Hot Water Condensing Blower Coil
Residential Boiler Accessories
Residential Steam Cast Iron Boilers
Compressors and Refrigeration
Compressors
AC Hermetic Compressor
Compressor Parts
Semi Hermetic Compressor
Tecumseh Refrigeration Compressor
Filter Driers
Refrigerant
Refrigerant Tanks
Refrigeration Controls
Refrigeration Controls Defrost
Refrigeration Controls Pressure
Refrigeration Controls Temperature
Refrigeration Equipment
Indoor Refrigeration Units
Refrigeration Equipment Parts
Wine Cellar Equipment
Refrigeration Oils / Flush / Additives
Refrigeration Specialties
Accumulators
Crankcase Heaters and Heat Tape
Expansion Valves and Devices
Liquid Line Indicators
Mufflers
Oil Control
Refrigeration Line Access Fittings
Refrigeration Valves Ball and Check
Refrigeration Valves Hot Gas
Refrigeration Valves Pressure Relief
Refrigeration Valves Regulating
Refrigeration Valves Reversing
Refrigeration Valves Service
Refrigeration Valves Solenoid and Coils
Vibration Eliminators
Controls
Actuators
Actuator Accessories
Floating Actuators
Modulating Actuators
Two Position Actuators
Electrical Components
Capacitors
Clocks and Timers
Contactors
Electrical Components
Fan & Limit Controls
Fan Center Relay
Relays
Special Purpose Switches
Time Delay Relays
Transformers
Gas and Ignition Components
Aquastats
Gas Burner Controls
Gas Valves
Ignition Kits
Pilot Devices
Pressure Regulators
Pressure Switches
Monitors and Alarms
Carbon Monoxide Alarms
Freeze Alarms
Monitoring Devices
Smart Home
Smoke Detection
Temperature Controllers
Humidity Sensors
Single Bulb Controllers
Single Bulb Modulating Controllers
Temperature Controllers
Temperature Transmitter and Sensors
Thermostats
Evolution and Infinity Controls
Line Voltage Thermostats
Low Voltage Non Programmable Thermostats
Low Voltage Programmable Thermostats
Thermostat Accessories
WIFI Thermostats
Zoning
Zone Panel Parts and Accessories
Zone Panels
HVAC Equipment
Commercial Equipment
Economizers
Electric Heat
Electric Baseboard
Electric Duct Heaters
Electric Fan Ceiling Heaters
Electric Heater Parts
Electric Makeup Air and Preheat
Electric Radiant Ceiling Heaters
Electric Unit Heaters
Electric Wall Heaters
Electric Heater Parts & Accessories
Evaporator Coils
Cased Coils
Coil Accessories
Uncased Coils
Factory Authorized Parts
FAP Blower Motors
FAP Blower Wheels
FAP Boards & Modules
FAP Condenser Coils
FAP Condenser Fan Motors
FAP Contactors
FAP Controllers
FAP Economizer and Damper Motors
FAP Electrical Parts
FAP Evaporator Coils
FAP Fan Blades and Propellers
FAP Fuses & Breakers
FAP Gas Burners
FAP Gas Heat Exchangers
FAP Gas Igniters
FAP Gas Limits & Timers
FAP Gas Parts
FAP Gas Valves
FAP Gaskets
FAP Generator Parts
FAP Hardware
FAP Inducer Motors
FAP Inducer Wheels
FAP Metering Parts
FAP Motor Modules
FAP Motor Mounts/Bearings/Shafts/Pulley
FAP Oil Burner Parts
FAP Paint
FAP Parts
FAP Pilots & Orifices
FAP Pistons
FAP Pressure Gauges
FAP Sight Glasses
FAP Switches & Relays
FAP Thermostats & Thermistors
FAP Transformers
FAP Wiring Harnesses
OEM Parts
Gas Heat
Gas Heater Parts & Accessories
Gas Radiant Heaters
Gas Unit Heaters
Gas Wall Furnaces
Geothermal
Geothermal Fittings
Geothermal Flow Centers
Geothermal Parts & Accessories
Geothermal Pipe
Geothermal Split System Heat Pumps
High Velocity
High Velocity Parts
High Velocity Units
PTAC
Packaged Terminal Parts & Accessories
Packaged Terminal Units
Residential A/C
Condensing Unit Accessories
Residential Ductless
Ductless Parts and Accessories
Residential Fan Coils
Fan Coil Electric Heaters
Fan Coil Parts & Accessories
Residential Ceiling Fan Coil
Residential Deluxe Fan Coil
Residential Entry Tier Fan Coil
Residential Mid Tier Fan Coil
Residential Furnaces
Gas 80 Furnaces
Gas 90 Furnaces
Furnace Accessories
Room A/C
Residential Room Air Conditioners
Thru the Wall Packaged Unit
Thru the Wall Parts & Accessories
Thru the Wall Split Condensing Unit
HVAC Supplies
Aftermarket Parts
Chemicals
Condensate Pumps
Condensate Lift Pump Parts
Condensate Lift Pumps
Condensate Pumps
Dampers
Duct Accessories
Fire and Smoke Dampers
Forced Air Dampers
Mechanical Air Dampers
Static Pressure Damper Controls
Flexible Gas
Flexible Gas Connectors and Fittings
Stainless Flexible Gas Pipe and Fittings
Installation Accessories
Electrical Installation Accessories
Fire Stop
Installation Accessories
Line Set Covers
Mounting Pads and Accessories
Safety and Protection Accessories
Solder Brazing Welding
Insulation
Duct Insulation
Flex Duct
Pipe Insulation
Linesets
Registers Grilles and Diffusers
Sheet Metal and Ductwork
Diverters and Draft Regulators
Galvanized Pipe
Galvanized Sheet Steel
High Velocity Insulated Spiral Duct
Intake and Exhaust Accessories
Rectangular Duct
Rectangular Duct Fittings
Sheet Metal Fittings
Spiral Duct and Fittings
Venting
A Vent
AL29-4C Stainless Steel Venting
Aluminum Venting
B Vent
Flexible Chimney Liners
Motorized Vent Dampers
Polypropylene Venting
Sheet Metal Venting Caps
Venting Accessories
Hydronics
Boiler Condensate
Steam Boiler Condensate Pump Parts
Steam Boiler Condensate Pumps
Boiler Water Treatment
Circulator Pumps
Bronze/Stainless Steel Circulator Pumps
Circulating Pump Accessories
Circulating Pump Parts
High Head ECM Circulator Pumps
High Head Iron Body Circulator Pumps
Pump Flanges and Unions
Standard Head ECM Circulator Pumps
Standard Head Iron Body Circulator Pumps
Hydronic Baseboard and Radiators
Cast Iron Baseboard
Cast Iron Baseboard Accessories
Cast Iron Radiators
Commercial Baseboard Accessories
Commercial Baseboard Enclosure Only
Commercial Element Only
Light Com Baseboard Enclosure Only
Light Commercial Baseboard Accessories
Light Commercial Element Only
Multi Fam Copper Fin Baseboard Complete
Multi Family Baseboard Accessories
Multi Family Baseboard Enclosure Only
Res Copper Fin Baseboard Complete
Residential Baseboard Accessories
Residential Baseboard Enclosure Only
Residential Copper Fin Element Only
Steel Radiators
Hydronic Controls
Flow Switches
Hydronic Controls
Hydronic Zone Pump Relays
Hydronic Zone Valve Control
LWCO and Feed Water Valve Parts
LWCO and Feed Water Valves
Thermometers and Thermaltimeters
Hydronic Heat
Hydronic Coils
Hydronic Convectors
Hydronic Fan Coil Parts and Accessories
Hydronic Fan Coils
Hydronic Heat Exchangers
Hydronic Unit Heaters
Hydronic Installation Accessories
Air Separators and Eliminators
Backflow Preventer
Boiler Expansion Tank Accessories
Boiler Expansion Tanks
Boiler Trim Kits
Combination Air and Dirt Separators
Dirt Separators and Strainers
Hot Water Air Vents
Hydraulic Separators
Potable Water Expansion Tanks
Pressure Reducing and Backflow Preventer
Pressure Reducing Valves
Pressure Relief Valves
Steam Trap Parts
Steam Traps
Steam Vents
Temperature and Pressure Relief Valves
Hydronic Valves
Miscellaneous Hydronic Valves
Tempering and Thermostatic Mixing Valves
Zone Valve Parts
Radiant Floor Heat
PEX Fittings
PEX Radiant Floor Tubing
PEX-AL-PEX Tubing
Radiant Floor Accessories
Radiant Floor Dry Panel Systems
Radiant Floor Manifolds
Indoor Air Quality
Air Filters
Air Purifiers
Commercial Recovery Ventilators
Dehumidifiers
Electronic Air Cleaners
Exhaust Fan Accessory
Exhaust Fans
Fan & Recovery Ventilator Controls
Humidifiers
Humidity Controls
IAQ Parts
Media Air Cleaners
Recovery Ventilator Accessories
Recovery Ventilator Parts
Residential Recovery Ventilators
UV Replacement Bulbs
Pipes, Valves, and Fittings
Aluminum Tubing
Brass
Brass Compression Fittings
Brass Flare Fittings
Brass Threaded Fittings
Misc Brass and Stainless Fittings
Copper
Copper Pipe and Tubing
Copper Sweat Fittings
Copper Press Fittings
Malleable Pipe
Black and Galvanized Iron Pipe
Black Iron Gas Press Fittings
Black Malleable Fittings
Black Pipe Nipples
Galvanized Malleable Fittings
Galvanized Pipe Nipples
Press Refrigeration Fittings
Push Fit Fittings, Copper PEX and CPVC
PVC and CPVC
PVC and CPVC Plastic Fittings
PVC and CPVC Plastic Pipe
Valves
Balancing Valves
Ball Valves
Boiler Drains and Hose Bibbs
Check and Flow Control Valves
Gas Ball Valves
Gate Valves
Globe Valves
Hydronic Zone Valves
Radiator Valves and Elbows
Vinyl Plastic Tubing
Tools
Combustion Analyzer Parts & Accessories
Combustion Analyzers
Digital Manifolds
Digital Vacuum Gauges
Hand Tools
Leak Detectors
Meters-Electrical/Temperature/Pressure
Power Tools
Press Tools
Radiant Install Tools
Refrigerant Gauges/Repair/Maint Parts
Refrigerant Hoses & Connectors
Refrigerant Recovery
Scales
Smart Probes
Standard Manifolds
Testing Devices & Accessoires
Tool Consumables
Vacuum Pumps
Tools All
Water Heaters
Commercial Electric Water Heaters
Commercial Gas Water Heaters
Com Gas Chimney Pilot Water Heaters
Com Gas Interm Ignition Water Heaters
Com Gas Sealed Combust Tank Water Heater
Commercial Gas Coil Water Heaters
Commercial Water Heater Accessories
Electric Heat Pump Water Heaters
Indirect Water Heaters
Indirect Water Heaters
Storage Tanks
Residential Electric Water Heaters
Electric Specialty Water Heaters
Electric Standard Water Heaters
Residential Gas Water Heaters
Chimney Vent Standard Water Heaters
Gas Dual Use Water Heaters
Mobile Home Water Heaters
Power Vent and Direct Vent Water Heaters
Tankless Water Heaters
Water Heater Parts
Indirect Water Heater Parts
Tankless Water Heater Parts
Water Heater Accessories
Water Heater Parts
Water Heater Relief Valves
Promotions
NTI Compass Promotion
2025 Promotions
Nu-Calgon Contractor Promotion
Brands
Training
Services
After Hours Emergency Service
Curbside Pickup
Delivery
Engineering Support
Marketing
Technical Support
Text Services
Warranty
Resources
Mobile App
Auer Rewards
FAQ
IAQ Resource Center
Line Cards
New Business Application
News & Updates
About Us
Auer Story
Auer Life
Auer Careers
Locations
Milwaukee
Neenah
Madison
Sheboygan
Sturtevant
Pewaukee
Woolworth
Plymouth
Fargo
Request Business Account
Cart (
)
{0} items in cart
Sign In
menu
Search
Cart
Home
/
Brands
/
Air Products and Controls
/
Shop All Products
/
4-Wire Photo-Electic Duct Smoke Detector
Air Products and Controls
Part #
D4120
MFG #
D4120
Login for Price
Share
Part #
D4120
4-Wire Photo-Electic Duct Smoke Detector
Login for Price
Share
Attributes
Brand:
Air Products and Controls
