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Navien Service, Repair & Annual Maintenance
Error code on the front panel? No hot water on a Saturday morning? Original installer ghosted you? We diagnose the root cause, fix what is actually broken, and get you on a real annual service schedule.
Johnson Bros. — Quincy & Abington offices. $99 service fee applies toward the work.
What a Real Navien Service Visit Covers
Heat exchanger descale (flush)
Pump cleaning solution through the heat exchanger for 45–60 minutes. Scale is the #1 killer of tankless units. Annual descaling is the most important service task.
Inlet water filter cleaning
Remove, inspect, rinse. Grit collects here and restricts flow if ignored.
Flame rod inspection
Flame rod fouling causes ignition codes (E003, E004). We clean or replace if needed.
Combustion analysis
We verify CO and O2 are within spec. This is how you know combustion is actually correct, not just that the unit fires.
Condensate trap & drain check
Blocked condensate trips lockouts. We clean the trap and verify the neutralizer media.
Error log review
We pull the Navien error log and look at what the unit has been telling you even if you missed it.
Common Navien Error Codes We Handle
Gas valve, flame rod, venting, or low gas pressure. See our E003 page for details.
Flame rod fouling, gas pressure, or combustion air. See E012 page.
Sensor or wiring. Straightforward diagnostic. See E027 page.
Scaling or reduced water flow through the heat exchanger. Usually a descale.
Low gas supply pressure. Often a gas-sizing issue, not a unit problem.
Venting obstruction or damper issue.
Common Questions About Navien Service
Why South Shore homeowners choose Johnson Bros.
Need Navien service or diagnostics?
Call if it's down or throwing a code so we can triage the visit. If you're setting up annual maintenance, book and we will put you on the schedule.
Need help fast? Call for urgent plumbing issues. Booking online is best when you want the next open appointment without waiting on the phone.
How We Work
Clear communication, licensed work, and local support.
Licensed Plumbing Work
Massachusetts-licensed plumbing support backed by insured crews.
Fast Scheduling Updates
We tell you what timing is available and keep you updated if the schedule shifts.
Upfront Options
You get a clear explanation of the work and price before the job begins.
Repair-First Guidance
We help you understand whether repair, replacement, or follow-up service makes the most sense.
Need Navien service or diagnostics?
Call if it's down or throwing a code so we can triage the visit. If you're setting up annual maintenance, book and we will put you on the schedule.
Call for urgent help now. Book online when you want the next available fit for your schedule.