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Furnace & HVAC Sensors

Furnace & HVAC Sensors

Shop furnace and HVAC replacement sensors for residential, commercial, and industrial heating and cooling systems. Furnace Part Source carries temperature sensors, immersion sensors, humidity sensors, flow sensors, and safety probes from Honeywell, Siemens, Veris Industries, MAMAC Systems, System Sensor, and other leading brands.

Use the product list below to find the correct sensor by part number, sensor type, or equipment model. Always confirm resistance value, output signal, mounting style, and equipment model before ordering to help avoid compatibility issues.

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    York Controls 025-47673-000 (replacement for 025-28935-000)

    York - Applied

    MSRP: $171.58
    Now: $132.59
    York Controls # 025-47673-000 Suction/liquid Line Temp Sensor Item is Non Cancelable / Non Returnable This is the direct replacement for 025-28935-000  FurnacePartSource
    MSRP: $171.58
    Now: $132.59
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    MSRP: $171.58
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    Siemens QPM2100 Co2 Duct Sensor, 0To10Vdc

    Siemens Building Technology

    MSRP: $614.84
    Now: $475.10
    Siemens QPM2100 Co2 Duct Sensor, 0To10Vdc  FurnacePartSource.com Commitment Item Typically Ships Within the Same Business Day Brand-New Genuine Parts - EverytimeNo Minimum Order Requirements
    MSRP: $614.84
    Now: $475.10
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    Siemens QPA2000 Room Sensor Co2 0-10Vdc

    Siemens Building Technology

    MSRP: $448.67
    Now: $346.70
    Siemens QPA2000 Room Sensor Co2 0-10Vdc  FurnacePartSource.com Commitment Item Typically Ships Within the Same Business Day Brand-New Genuine Parts - EverytimeNo Minimum Order Requirements
    MSRP: $448.67
    Now: $346.70
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    MSRP: $448.67
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    Siemens QFM3160 Temp/Rh Sensor 2 0/10Vdc Outpt

    Siemens Building Technology

    MSRP: $362.42
    Now: $280.05
    Siemens QFM3160 Temp/Rh Sensor 2 0/10Vdc Outpt  FurnacePartSource.com Commitment Item Typically Ships Within the Same Business Day Brand-New Genuine Parts - EverytimeNo Minimum Order Requirements
    MSRP: $362.42
    Now: $280.05
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    MSRP: $362.42
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    Siemens QFM3101 Sensor, Duct Rg 2%

    Siemens Building Technology

    MSRP: $328.45
    Now: $253.80
    Siemens QFM3101 Sensor, Duct Rg 2%   FurnacePartSource.com Commitment Item Typically Ships Within the Same Business Day Brand-New Genuine Parts - Everytime No Minimum Order Requirements    
    MSRP: $328.45
    Now: $253.80
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    Siemens QFM3100 Sensor Duct Rh 0-10Vdc

    Siemens Building Technology

    MSRP: $328.45
    Now: $253.80
    Siemens QFM3100 Sensor Duct Rh 0-10Vdc  FurnacePartSource.com Commitment Item Typically Ships Within the Same Business Day Brand-New Genuine Parts - EverytimeNo Minimum Order Requirements
    MSRP: $328.45
    Now: $253.80
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    Siemens QFM2171 Duct Sensor 4-20 Ma

    Siemens Building Technology

    MSRP: $264.86
    Now: $204.66
    Siemens QFM2171 Duct Sensor 4-20 Ma  FurnacePartSource.com Commitment Item Typically Ships Within the Same Business Day Brand-New Genuine Parts - EverytimeNo Minimum Order Requirements
    MSRP: $264.86
    Now: $204.66
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    MSRP: $264.86
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    Siemens QFM2101 Sensor (Duct) Rh 4-20 Ma Output

    Siemens Building Technology

    MSRP: $230.08
    Now: $177.79
    Siemens QFM2101 Sensor (Duct) Rh 4-20 Ma Output   FurnacePartSource.com Commitment Item Typically Ships Within the Same Business Day Brand-New Genuine Parts - Everytime No Minimum Order Requirements...
    MSRP: $230.08
    Now: $177.79
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    MSRP: $230.08
    Now: $177.79
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    Siemens QFA32SS.EWSN Humid/Temp Sensor 0-10Vdc Wht, 2%

    Siemens Building Technology

    MSRP: $254.69
    Now: $196.81
    Siemens QFA32SS.EWSN Humid/Temp Sensor 0-10Vdc Wht, 2%  FurnacePartSource.com Commitment Item Typically Ships Within the Same Business Day Brand-New Genuine Parts - EverytimeNo Minimum Order...
    MSRP: $254.69
    Now: $196.81
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    Siemens QFA3171 Outside Air Rh/Temp Sens 4-20

    Siemens Building Technology

    MSRP: $402.55
    Now: $311.06
    Siemens QFA3171 Outside Air Rh/Temp Sens 4-20  FurnacePartSource.com Commitment Item Typically Ships Within the Same Business Day Brand-New Genuine Parts - EverytimeNo Minimum Order Requirements
    MSRP: $402.55
    Now: $311.06
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    MSRP: $402.55
    Now: $311.06
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    Siemens QFA3160 Rh 0-10Vdc T 0-10Vdc

    Siemens Building Technology

    MSRP: $402.55
    Now: $311.06
    Siemens QFA3160 Rh 0-10Vdc T 0-10Vdc  FurnacePartSource.com Commitment Item Typically Ships Within the Same Business Day Brand-New Genuine Parts - EverytimeNo Minimum Order Requirements
    MSRP: $402.55
    Now: $311.06
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    MSRP: $402.55
    Now: $311.06
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    Siemens QFA3101 Humidity Sensor 4/20Ma

    Siemens

    MSRP: $271.97
    Now: $206.04
    Siemens QFA3101 Humidity Sensor 4/20Ma  FurnacePartSource.com Commitment Item Typically Ships Within the Same Business Day Brand-New Genuine Parts - EverytimeNo Minimum Order Requirements
    MSRP: $271.97
    Now: $206.04
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    MSRP: $271.97
    Now: $206.04
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    Siemens QAP22 Cable Temp Sensor 6'

    Siemens

    MSRP: $24.90
    Now: $18.86
    Siemens QAP22 Cable Temp Sensor 6'  FurnacePartSource.com Commitment Item Typically Ships Within the Same Business Day Brand-New Genuine Parts - EverytimeNo Minimum Order Requirements
    MSRP: $24.90
    Now: $18.86
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    MSRP: $24.90
    Now: $18.86
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    Siemens QAM2030.750 10K Ohm Ntc Duct Sensor, 24'Prob,Tp2

    Siemens Building Technology

    MSRP: $140.05
    Now: $108.22
    Siemens QAM2030.750 10K Ohm Ntc Duct Sensor, 24'Prob,Tp2   FurnacePartSource.com Commitment Item Typically Ships Within the Same Business Day Brand-New Genuine Parts - Everytime No Minimum...
    MSRP: $140.05
    Now: $108.22
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    MSRP: $140.05
    Now: $108.22
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    Siemens QAM2030.500 10K Ohm Ntc Duct Sensor, 16'Prob,Tp2

    Siemens Building Technology

    MSRP: $118.95
    Now: $91.91
    Siemens QAM2030.500 10K Ohm Ntc Duct Sensor, 16'Prob,Tp2  FurnacePartSource.com Commitment Item Typically Ships Within the Same Business Day Brand-New Genuine Parts - EverytimeNo Minimum Order...
    MSRP: $118.95
    Now: $91.91
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    MSRP: $118.95
    Now: $91.91
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    Siemens QAM2030.250 10K Ohm Ntc Duct Sensor, 8'Prob,Typ2

    Siemens Building Technology

    MSRP: $107.32
    Now: $82.93
    Siemens QAM2030.250 10K Ohm Ntc Duct Sensor, 8'Prob,Typ2 Duct Temperature Sensor 10k Oh
    MSRP: $107.32
    Now: $82.93
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    MSRP: $107.32
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    Siemens QAM2030.045 10K Ohm Ntc Duct Sensor, 18"Prob,Ty2

    Siemens Building Technology

    MSRP: $37.36
    Now: $28.87
    Siemens QAM2030.045 10K Ohm Ntc Duct Sensor, 18"Prob,Ty2  FurnacePartSource.com Commitment Item Typically Ships Within the Same Business Day Brand-New Genuine Parts - EverytimeNo Minimum Order...
    MSRP: $37.36
    Now: $28.87
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    MSRP: $37.36
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    Siemens QAM2030.020 10K Ohm Ntc Duct Sensor, 8"Prob, Typ2

    Siemens Building Technology

    MSRP: $35.51
    Now: $27.44
    Siemens QAM2030.020 10K Ohm Ntc Duct Sensor, 8"Prob, Typ2  FurnacePartSource.com Commitment Item Typically Ships Within the Same Business Day Brand-New Genuine Parts - EverytimeNo Minimum Order...
    MSRP: $35.51
    Now: $27.44
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    MSRP: $35.51
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    Siemens QAM2030.010 Duct Sensor 10K Ohm 4" Long

    Siemens Building Technology

    MSRP: $33.86
    Now: $26.16
    Siemens QAM2030.010 Duct Sensor 10K Ohm 4" Long  FurnacePartSource.com Commitment Item Typically Ships Within the Same Business Day Brand-New Genuine Parts - EverytimeNo Minimum Order Requirements
    MSRP: $33.86
    Now: $26.16
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    MSRP: $33.86
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Furnace & HVAC Sensors

Furnace and HVAC sensors monitor temperature, airflow, flame presence, humidity, and other conditions that keep a heating or cooling system operating safely and efficiently. When a sensor fails or reads inaccurately, it can cause lockouts, poor comfort control, or unsafe operation.

Furnace Part Source carries a wide range of replacement sensors, including duct and immersion temperature sensors, outside air sensors, humidity sensors, flow sensors, and safety-related probes for residential, commercial, and industrial HVAC equipment.

Common Sensors We Carry

Common replacement sensors include:

  • Duct and immersion temperature sensors for supply, return, and water temperature readings.
  • Outside air temperature and humidity sensors for outdoor reset and economizer control.
  • Flow sensors for airflow and duct pressure monitoring.
  • Low-level and safety probe sensors for boiler and water-level protection.
  • Gas and smoke detection sensors for combustible gas and safety monitoring.

How to Find the Right Sensor

Before ordering, confirm the sensor's resistance value (such as 10K or 20K ohm), output signal type, mounting style, and the equipment model it is used with. Sensors that look similar can have different resistance curves or output signals, so matching by part number is the safest approach.

For best fit, compare:

  • Original sensor part number
  • Resistance value or output signal type
  • Sensor style, such as duct, immersion, outside air, or surface-mount
  • Equipment model and control system

Sensors From Leading HVAC Brands

Our catalog includes sensors from Honeywell, Siemens Building Technology, Veris Industries, MAMAC Systems, System Sensor, Dwyer Instruments, Aaon, Kele, and other major manufacturers, covering both standard replacement sensors and specialized industrial sensing equipment.

Need Help Matching a Sensor?

Not sure which sensor you need? Use the part number, resistance value, and control system information from your equipment to narrow the search, or contact Furnace Part Source for help identifying the correct replacement.

HVAC Sensor FAQs

What types of sensors does an HVAC system use?

HVAC systems commonly use temperature sensors, humidity sensors, flow sensors, flame sensors, and safety probes to monitor conditions and support proper system control.

How do I know what resistance value my sensor needs?

Check the original sensor's part number or the equipment documentation, which typically lists the resistance value, such as 10K or 20K ohm, required for compatibility.

Can a bad sensor cause my system to shut down?

Yes. A failed or inaccurate sensor reading can trigger lockouts or prevent proper operation, particularly for safety-related sensors like low-water or flame sensors.

Are furnace sensors and thermostat sensors the same?

No. Furnace and HVAC sensors typically monitor internal equipment conditions, while thermostat sensors read room temperature for comfort control. Always confirm the specific application before ordering.