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IO HVAC Controls FS-38 Suction Line Freeze Thermostat

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Special Price $36.75 Regular Price $47.77
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SKU
FS-38
IO HVAC Controls FS-38 Suction Line Freeze Thermostat is a temperature sensor used in HVAC systems to minimise the freezing of evaporator coils. It measures the suction line and switches its internal switch when the conditions are below a set temperature to allow the control system to regulate the compressor operation. It is mounted on the suction line just outside the evaporator and is connected to electrical system. In heat pump and air conditioning HVAC systems, the thermostat assists in maintaining the proper coil temperature, avoids ice formation on equipment and optimal and efficient operation under different load conditions.
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Specifications

  • Type: Suction Line Freezestat

    Product Overview:
    Provides low-temperature protection for compatible air conditioning systems by monitoring suction line temperature to help prevent evaporator coil freeze-up. The iO HVAC Controls FS-38 Suction Line Freeze Thermostat is an OEM protective control designed for compatible HVAC applications. It responds to low-temperature conditions through an electrical switching mechanism that helps interrupt cooling operation when necessary.

    Freeze Protection Switching:
    The thermostat responds to temperature changes at the suction line through its sensing mechanism. When the temperature drops to the opening threshold, the electrical contacts open. As the temperature rises to the closing threshold, the contacts return to their closed state, resetting the thermostat's switching action.

    HVAC Control Circuit Integration:
    The FS-38 is installed on the suction line and connected in series with the cooling control circuit. When its contacts open, the thermostat interrupts the cooling call to help prevent continued operation under conditions that could lead to evaporator coil icing. This provides a protective control response without directly regulating refrigerant flow.

    Replacement Guidelines:
    The iO HVAC Controls FS-38 Suction Line Freeze Thermostat may require replacement when the existing unit is physically damaged or its freeze-protection function no longer operates as intended. Replacement may be appropriate when the thermostat cannot reliably respond to low suction line temperatures or restore its contacts after the temperature rises.

    Common Failure Symptoms:

    • Air conditioning system continues operating during low suction line temperature conditions.
    • Evaporator coil repeatedly develops ice buildup.
    • Cooling operation is interrupted unexpectedly.
    • Thermostat contacts fail to open or close as intended.
    • Freeze protection does not reset after the suction line temperature rises.
    • Physical damage affects the thermostat or its snap-on attachment.

    Equipment Compatibility:
    The iO HVAC Controls FS-38 Suction Line Freeze Thermostat is an OEM replacement component intended for compatible systems requiring suction line freeze protection. It is also identified as a replacement for the Trol-A-Temp FPC. Verify the existing part number, suction line installation requirements, and cooling control circuit arrangement before ordering. Specific compatible equipment model numbers have not been confirmed.

    Technical Specifications:
    Brand: IO HVAC Controls
    Part Number: FS-38
    Product Type: Suction Line Freeze Thermostat

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    Product Questions (7)
    Customer Questions
    What maintenance is required for the IO HVAC Controls FS-38 Thermostat?

    Inspect the thermostat and sensing element for proper placement and secure attachment to the suction line. Check wiring connections for wear or looseness. Routine maintenance ensures accurate temperature detection and prevents coil freeze-ups. Always disconnect power before handling electrical components.

    What are common issues with the IO HVAC Controls FS-38 Thermostat?

    • Inaccurate temperature sensing.
    • Failure to trigger system shutdown.
    • Loose or damaged wiring connections.
    • Improper mounting on suction line.
    • Intermittent operation or false readings.

    What is the primary function of the IO HVAC Controls FS-38 suction line freeze thermostat?

    It monitors suction line temperature and helps protect compatible HVAC equipment from freeze-related conditions.

    How does the IO HVAC Controls FS-38 freeze thermostat operate?

    It responds to changes in suction line temperature and operates its electrical contacts at the designated temperature threshold to initiate the configured protective response.

    How can I verify that the IO HVAC Controls FS-38 OEM replacement freeze thermostat is compatible with my equipment?

    Check the existing part number, temperature operating range, contact configuration, electrical ratings, mounting method, and suction line connection requirements.

    When should the IO HVAC Controls FS-38 freeze thermostat be replaced?

    Replace it when physically damaged or when its temperature-sensing and switching functions no longer operate as intended.

    What are the common signs of a faulty IO HVAC Controls FS-38 freeze thermostat?

    Common signs include failure to respond to low suction line temperatures, incorrect contact switching, intermittent operation, and unreliable freeze protection.

    Installation Steps

    Step 1: Turn off HVAC power to ensure safety before beginning installation.

    Step 2: Select a clean, accessible section of the suction line for mounting.

    Step 3: Attach the thermostat sensor securely to the suction line using the provided straps or clamps.

    Step 4: Connect wiring according to the manufacturer’s instructions, ensuring proper electrical connections.

    Step 5: Restore power and test the system to confirm the thermostat correctly monitors and protects against freezing.