How To Flush Descale Tankless Water Heater and Maintenance heat exchanger Navien NCB240 Combi Boiler

How to Flushing and descaling the heat exchangers on a Navien Combination boiler with vinegar. Clean condensate trap, clean water inlet filter, clean space heat strainer filter. Maintenance. This can prevent the 3 way valve from going bad. Another step I didn't do is to open the 3 way valve when flushing the space heat side to make sure the space heat and domestic plate exchangers get flushed.