Navien Plate Heat Exchanger 30018297B

This is a plate heat exchanger manufactured by Navien, supplied under part number 30018297B. It is a brazed plate component used in Navien combi boilers to transfer heat between the primary heating circuit and the domestic hot water circuit. The plate stack separates the two water paths while allowing heat to pass across the plates.

• Domestic hot water runs hot then cold, or the temperature at the tap fluctuates while the heating stays steady
• Reduced hot water flow rate compared with the cold supply at the same outlet
• Heating works correctly but the hot water tap stays cold or only warms slightly
• Water weeping from the plate pack or from the connections around the exchanger
• Sludge or scale build-up in the plate channels restricting flow and heat transfer

• Confirm the boiler model matches one of the appliances listed above before ordering
• Check the boiler serial number against the appliance data plate to confirm the correct build
• Inspect the plate connections and seals for damage, since disturbed joints can weep after refitting
• Verify the existing part number on the removed component against 30018297B