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Navien E515 — Control Board (PCB) Fault
Your Navien's control board flagged an abnormal condition in itself or a part it monitors. It's a protective lockout that points to the PCB and its connected components.
What E515 Means
E515 is a control-board (PCB) fault. The board runs continuous self-checks and monitors key components — the igniter, fan, gas valve, and venturi among them. When it detects a condition it can't reconcile, it posts E515 and locks the unit out as a safety measure.
Sometimes the board itself has failed; other times a component it watches, or a loose connection to it, is the real problem. Because the board sits at the center of everything, E515 needs methodical diagnosis — we check connections and monitored parts before condemning the PCB, since the board is one of the pricier components.
Common Causes of E515
1. Control-board (PCB) failure
The board itself can fail after years of heat and electrical cycling. When testing confirms it, replacement restores the unit.
2. A monitored component faulting
The board watches the igniter, fan, dual venturi, and 3-way valve. A fault in one of those can surface as E515 — so we test them before replacing the board.
3. Loose or corroded connectors
A poor connection at the board can mimic a board failure. Reseating and cleaning connections sometimes clears it outright.
4. Power-supply irregularity
Unstable incoming power or a grounding issue can upset the board's self-checks. We verify clean power as part of the diagnosis.
E515 FAQs
Why South Shore homeowners choose Johnson Bros.
Navien showing E515? We diagnose before we replace the board.
The PCB is a costly part, so we test connections and monitored components first. Tell us your model and we'll methodically work it.
Need help fast? Call for urgent plumbing issues. Booking online is best when you want the next open appointment without waiting on the phone.
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Navien showing E515? We diagnose before we replace the board.
The PCB is a costly part, so we test connections and monitored components first. Tell us your model and we'll methodically work it.
Call for urgent help now. Book online when you want the next available fit for your schedule.