Hydrolevel 400R Low Water Cut-Off Refrigerant high-altitude installations (typically above 2

high-altitude installations (typically above 2

The Watts 0887371 kit provides the critical components needed to restore the differential pressure relief valve to factory-spec tight-sealing performance

Check your valve body casting for size confirmation before installation

99+% of oil aerosols and solid particles down to 0

When troubleshooting a fan-forced heater that fails to power or has a damaged physical interface

Hydrolevel 400R Low Water Cut-Off Refrigerant high-altitude installations (typically above 2The Hydrolevel 400R (Part Number 45 402) is a professional grade 24VAC low water cut off designed specifically for steam boiler applications where a remote mounting configuration is required. As a primary safety control, the 400R utilizes a non cycling design, ensuring the burner circuit remains interrupted until a safe water level is restored. This model includes the EL1214 R sensing probe and a dedicated junction box, providing the flexibility