Rinnai 807000052 12L Expansion Vessel for E110C Hydronic Heating System

The Rinnai 807000052 is a 12-liter expansion vessel engineered specifically for use with the Rinnai E110C hydronic heating system. Expansion vessels are a critical safety and performance component in closed-loop hydronic heating systems, absorbing pressure fluctuations caused by the thermal expansion of water as it heats and cools during normal operation.

By maintaining stable system pressure, this expansion vessel helps protect the boiler, pipework, and other hydronic components from pressure-related stress and potential damage. The sealed diaphragm design separates the water side from the pre-charged nitrogen or air cushion, ensuring reliable pressure absorption over the life of the system.

Key Features:

• 12-liter (12L) capacity — sized to accommodate system volume requirements of the E110C
• Designed as a genuine Rinnai OEM replacement part for the E110C hydronic heating series
• Sealed diaphragm construction for consistent pressure management
• Protects system components from overpressure conditions
• Helps maintain efficient and safe closed-loop hydronic system operation
• Direct-fit replacement — no modifications required

This is a genuine Rinnai replacement part (OEM part number 807000052), ensuring proper fit, function, and compatibility with the E110C system. Recommended for use when the existing expansion vessel shows signs of waterlogging, diaphragm failure, or loss of pre-charge pressure.