General Pump Compact Thermal Relief Valve 1/2" MPT 145°F – OEM Replacement Part

Part Number: 100558
Category: Pressure Washer Components → Thermal Relief Valves → General Pump Parts
Type: General Pump Compact Thermal Relief Valve

The General Pump Compact Thermal Relief Valve (Part #100558) is a genuine OEM safety device designed to protect pressure washer pumps from damaging heat buildup during bypass operation. Engineered to automatically activate at approximately 145°F, this thermal relief valve releases overheated water from the system and allows cooler water to enter, helping prevent damage to seals, packings, valves, and other internal pump components.

Key Features & Benefits

• Genuine General Pump OEM Replacement Part
• Protects pumps from overheating during bypass operation
• Automatically opens at approximately 145°F
• Automatic reset functionality after cooling
• Compact design for easy installation
• Helps prevent premature seal and packing failure
• Reduces wear caused by excessive pump temperatures
• Suitable for high-flow pressure washer systems
• Improves pump reliability and service life
• Cost-effective pump protection solution

Technical Specifications

Manufacturer: General Pump

Part Number: 100558

Product Type: Thermal Relief Valve

Connection Size: 1/2" MPT

Connection Type: Male Pipe Thread (MPT)

Activation Temperature: 145°F

Reset Type: Automatic Reset

Application: Pump Overheat Protection

OEM Replacement: Yes

Typical Applications

• Pressure washer systems
• Commercial pressure washing equipment
• Industrial cleaning systems
• High-flow pump installations
• Pump bypass loops
• Mobile wash rigs
• Equipment wash bays
• Custom pressure washer builds

Performance Advantages

• Automatically protects pumps from heat-related damage
• Prevents overheating during extended bypass operation
• Extends seal, packing, and internal component life
• Helps reduce maintenance and repair costs
• Automatic reset operation requires no manual intervention
• Compact profile simplifies installation
• Supports long-term pump reliability and efficiency
• Ideal for commercial and industrial applications
• Helps maximize the lifespan of pressure washer pumps

Installation Locations

The General Pump 100558 Thermal Relief Valve can be installed in:

• Pump manifold ports
• Bypass plumbing loops
• Inlet water supply plumbing
• High-flow pressure washer systems
• Pump protection circuits

Always follow equipment manufacturer recommendations regarding installation location and plumbing configuration.

Maintenance Recommendations

• Inspect the thermal relief valve periodically for leaks or physical damage.
• Verify proper activation and reset operation during routine maintenance.
• Replace valves showing signs of wear or malfunction.
• Ensure adequate water supply to the pump system.
• Follow General Pump installation and service guidelines.
• Use only genuine OEM replacement parts to maintain factory performance and reliability.