Dhw Heat Exchanger - Navien NCB300-28K Service Manual

4.7.12 DHW Heat Exchanger

Item Description
Heat transfer between space heating and DHW water. Water heated in the primary and secondary heat
Function exchangers is circulated to the plate heat exchanger. Also, the plate heat exchanger filters the water in the
space heating system to prevent faults in other parts of the heating system.
1. Water leaks.
Fault
2. Low temperature water in the heat exchanger.
Symptoms DHW leaks and/or temperature fluctuations at hot water outlets.
Error codes E016, E030, E353
A leaking plate heat exchanger causes the space heating side system pressure to rise to the tap water
Diagnostics
pressure level. Check the pressure in the space heating system.
48 System Details