Tankless descaling and service in Salem

Salem's city water comes from the North Santiam River and is naturally soft, so homeowners sometimes assume their tankless unit never needs descaling. Soft water does slow mineral buildup, but the narrow passages in a heat exchanger still collect fine sediment and grit, and some scale forms over time with heavy use. Left alone, that debris slowly chokes the flow.

Manufacturers also set a service schedule in the owner's manual, and keeping to it keeps the unit running the way it was designed to, with a clean exchanger and a burner that lights on the first try. A yearly visit that flushes the exchanger and checks the burner and vent catches small problems before a cold morning shower turns into a no-heat call.

Why soft Salem water still calls for flushing

Soft water carries fewer of the hard minerals that leave white crust on fixtures, but it is not clean of everything. Fine sediment, bits of pipe scale and grit from main work in the street all travel to the heater. In a tank, that debris settles to the bottom. In a tankless unit, it catches in the inlet screen and the small tubes of the heat exchanger, where it restricts flow and makes the unit work harder.

How a descaling flush works

We close the isolation valves, connect a small pump and hoses to the service ports, and circulate a descaling solution through the heat exchanger for a set period. The solution loosens scale and sediment, which flushes out into the bucket. Then we rinse with clean water until it runs clear and reopen the valves.

• Shut gas or power and close isolation valves
• Circulate descaler through the exchanger with a pump
• Rinse with fresh water until it runs clear
• Pull and clean the inlet screen before restarting

Checking the burner, flame rod, fan and venting

Beyond the water side, a tankless unit has a combustion side that needs attention. We inspect the burner for even flame, clean the flame rod so the control can sense the burner reliably, and check that the fan spins freely without noise. We look at the vent for blockages from nests or debris and confirm every joint is sealed. On condensing models, we flush the condensate trap and check the neutralizer, since a clogged trap can shut the unit down.

Reading error codes and fixing common faults

Most units store recent error codes, which point to ignition failures, flame loss, overheating, low flow or a blocked vent. We read the history and compare it with what we see on the unit. A unit that cuts out during long showers may have a dirty flow sensor or a restricted exchanger.

Repeated ignition errors can trace back to low gas pressure, a loose gas connector or a worn igniter. We fix the cause rather than clearing the code and hoping it stays gone, then run the unit through a full heating cycle to confirm.