The Bosch Protankless Upper O-ring, part number 87002051330, is a replacement sealing component designed for use within the water valve assembly of compatible Bosch Protankless tankless gas water heaters. This O-ring provides a critical sealing function at the upper position of the water valve, preventing water leakage and maintaining pressure integrity within the heater's internal water pathway. It is a factory-specified replacement part intended to restore the water valve to proper operating condition.
The upper O-ring seats within the water valve body and forms a watertight seal at the upper junction of the valve assembly. Over time, O-rings in tankless water heater applications are subject to wear, compression set, and degradation from heat cycling and mineral exposure, making periodic inspection and replacement a standard maintenance procedure. Replacing a worn or damaged upper O-ring restores the integrity of the valve seal and prevents water intrusion into surrounding components.
What's Included: One Bosch Protankless upper O-ring replacement seal, part number 87002051330.
Installation Limits: This O-ring is specific to the upper sealing position within the water valve assembly. It is not interchangeable with the lower O-ring of the same assembly. Installation requires accessing the internal water valve of the heater and should be performed with the water supply isolated and the unit depressurized.
Compatibility: Compatible with the Bosch Protankless 520HN tankless gas water heater water valve assembly.
