Introduction
This manual provides essential information for the safe and efficient operation, installation, and maintenance of the 157S-P Float Type Combo LWCO & Pump Controller. Please read this manual thoroughly before installation or operation.
Product Overview
The 157S-P is a float-type combination low water cut-off (LWCO) and pump controller designed for residential, commercial, and industrial low or high-pressure boiler applications. It features a Monel bellows for corrosion resistance, an integral water column, and snap-action switches for reliable high-temperature service. It includes one single-pole, single-throw (SPST) switch for pump control and one single-pole, double-throw (SPDT) switch for low water cut-off and alarm actuation.
Figure 1: The 157S-P Float Type Combo LWCO & Pump Controller. This image shows the main unit with its float chamber and integrated switch assembly, designed for boiler water level management.
Specifications
| Feature | Detail |
|---|---|
| Application | Boilers (Steam Boilers) |
| Reset Type | Automatic |
| Maximum Pressure | 150 psi |
| Switch Type | SPDT (Low Water Cut-off/Alarm), SPST (Pump Control) |
| Electrical Ratings (AFL) | 3.7 A @ 240 VAC, 7.4 A @ 120 VAC |
| Electrical Ratings (ALR) | 22.2 A @ 240 VAC, 44.4 A @ 120 VAC |
| Pilot Duty Rating | 345 VA |
| Connection Type | Threaded |
| Thread Size | 1 inch |
| Depth | 13 3/8 inches |
| Length | 16 inches |
| Width | 5 7/8 inches |
Safety Information
Always observe safety precautions when working with boiler systems. Failure to do so may result in serious injury or property damage.
- Ensure power to the boiler is disconnected before installation or servicing.
- Follow all local codes and regulations for boiler installation and maintenance.
- Only qualified personnel should perform installation and maintenance.
- Wear appropriate personal protective equipment (PPE).
- Do not bypass safety devices.
Installation
The 157S-P controller is designed for easy integration into boiler systems. Proper installation is crucial for optimal performance and safety.
Mounting
- Mount the unit vertically on the boiler, ensuring the float chamber is level.
- Connect the unit to the boiler using the 1-inch threaded connections. Ensure a tight, leak-free seal.
- Utilize the side ports for additional connections as required by your boiler system configuration.
Electrical Wiring
Wiring should be performed by a licensed electrician in accordance with all local and national electrical codes.
- The unit includes one single-pole, single-throw (SPST) switch for pump control and one single-pole, double-throw (SPDT) switch for low water cut-off and alarm actuation.
- Connect the pump control switch to the boiler feed pump circuit.
- Connect the low water cut-off switch to the boiler's safety circuit to shut down the burner in a low water condition.
- Connect the alarm actuation contacts to an audible or visual alarm system.
- Refer to the wiring diagram provided with the product packaging for specific connection points.
Operation
The 157S-P operates automatically to maintain safe water levels and control the boiler feed pump.
Normal Operation
- As the boiler water level drops, the float within the chamber descends.
- When the water level reaches the pump control set point, the SPST switch activates the boiler feed pump to replenish water.
- If the water level continues to drop below the safe operating level, the float will activate the SPDT low water cut-off switch, shutting down the boiler burner and activating any connected alarm.
- The low water cut-off is automatic reset; once water is restored to a safe level, the switch will reset, allowing the boiler to resume operation (if other safety interlocks permit).
Maintenance
Regular maintenance ensures the longevity and reliable operation of your 157S-P controller.
Daily Checks
- Visually inspect the unit for any signs of leaks or damage.
- Verify that the boiler water level is within normal operating range.
Weekly / Monthly Checks
- Blowdown: Perform a blowdown of the float chamber to remove sediment and ensure free movement of the float. Follow boiler manufacturer's guidelines for blowdown procedures.
- Test Low Water Cut-off: Periodically test the low water cut-off function by manually lowering the water level (if safe to do so, following boiler manufacturer's instructions) or by using a test button if available on your boiler system. Ensure the burner shuts off and the alarm activates.
Annual Inspection
- Have a qualified technician inspect the unit for wear, corrosion, and proper calibration.
- Check electrical connections for tightness and signs of overheating.
- Inspect the Monel bellows for any signs of damage or fatigue.
Troubleshooting
This section provides solutions to common issues. For problems not listed, contact a qualified service technician.
| Problem | Possible Cause | Solution |
|---|---|---|
| Pump not activating when water level drops. |
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| Boiler shuts down due to low water, but water level is adequate. |
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| Unit leaking. |
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Warranty and Support
For warranty information or technical support, please contact the manufacturer or your authorized dealer. Keep your purchase receipt for warranty claims.
Manufacturer: Generic
Part Number: SPH-175802
Date First Available: February 3, 2025
For further assistance, please refer to the contact information provided with your product documentation or visit the Generic brand website.
