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    Johnson Bros. Plumbing & Drain Cleaning

    Navien Tankless & Combi-Boiler Specialists — South Shore, MA

    New install, stuck error code, or annual descaling — we handle Navien NPE tankless water heaters and NCB/NFB combi boilers across Greater Boston and the South Shore.

    Johnson Bros. is a family-owned plumbing and heating company based in Quincy & Abington. $99 service fee applies toward the work. Permits pulled on every install.

    Call (617) 479-9911Book Navien Service
    4.8 stars on Google · 367 reviews across Quincy and AbingtonMA Lic. PL #17034-MFamily-owned · not a franchiseQuincy & Abington offices
    Why Navien

    Tankless & combi systems built to outwork your old tank by a decade.

    A well-installed Navien NPE tankless or NCB combi boiler runs efficiently for 20 years, gives you endless hot water, cuts gas use, and frees up floor space. The key phrase is well-installed. Gas sizing, venting, condensate, and commissioning all have to be right. That’s the part that separates a Navien that lasts from one that throws an error every six months.

    Endless hot water

    A properly sized NPE delivers hot water continuously — no running out during back-to-back showers or when the dishwasher runs with the laundry.

    Lower gas bills

    Modulating condensing combustion means 30–50% less gas than a traditional tank. On a cold Boston winter, that difference shows up on every bill.

    Wall-mounted, out of the way

    A Navien wall-mount unit frees up the closet or basement floor a 50-gallon tank used to own. Good for older Quincy and Milton homes with tight mechanical spaces.

    Navien Models We Install & Service

    NPE Series — Tankless Water Heaters
    • NPE-A2 — advanced, built-in recirculation for instant hot water
    • NPE-S2 — standard condensing tankless
    • High-efficiency gas use (up to 0.96 UEF)
    • Sized 150k–199k BTU for most homes
    NCB Series — Combi Boilers
    • NCB-E series — hydronic heat + domestic hot water in one unit
    • Replaces a separate boiler + water heater
    • Great fit for 1–2 zone South Shore homes
    • Wall-mount, compact footprint
    NFB / NFC — High-Capacity Combis
    • NFB-C — higher BTU heating for larger homes & multi-zone
    • Strong domestic hot water delivery (3+ fixtures)
    • Advanced diagnostics for faster troubleshooting
    • Condensing, low-NOx, meets current MA code

    What We Do With Your Navien

    New Installation & Tank-to-Tankless Conversion

    We walk the install with you before anything gets torn out — gas sizing, venting path, condensate drain, electrical, recirc loop if you want it, permit, inspection. Clean, code-compliant, documented.

    See our Navien install process
    Error Codes, No-Hot-Water & Repair

    Unit locked out with an error code? No hot water on a Saturday? We diagnose the root cause — not just clear the code and leave. Common codes we handle: E003, E012, E027, and many others.

    Navien repair & diagnostics
    Annual Descaling & Maintenance

    Navien units need an annual flush of the heat exchanger — descale, clean the inlet filter, inspect the flame rod, verify combustion. Skipping this is the #1 reason tankless units fail early. Family Plan members get priority scheduling and no service-call fee.

    Take-Over & Warranty Service

    Original installer is out of business, not returning calls, or did sloppy work? We take over service on existing Navien units, fix the bad venting or gas sizing, re-commission the unit, and get you back on an annual maintenance schedule.

    Signs Your Navien Needs Service

    Error Code on the Front Panel

    E003, E012, E016, E027, E040, A012 — each tells us something specific. We read the code and the combustion/flow data behind it to find the actual cause.

    Cold-Water Sandwich or Delayed Hot Water

    If you get a cold blast between hot draws, it's usually a recirculation or minimum-flow issue. Often solvable without replacing the unit.

    Short-Cycling or Rumbling on Start

    Usually points to scaling, low gas pressure, or a dirty flame rod. A proper descale plus a flame-rod clean fixes the majority of these cases.

    Hot Water Flow Has Dropped

    A clogged inlet filter or scaled heat exchanger will reduce output. Part of an annual service visit — often overlooked by non-specialists.

    Some High-Efficiency Navien Units Qualify for Mass Save Rebates

    Massachusetts Mass Save periodically offers rebates on qualifying high-efficiency gas water heating and heat pump water heaters. We install qualifying equipment and point you to the current program details so your paperwork lines up.

    See Mass Save Details

    Navien Service Across Greater Boston & the South Shore

    From our Quincy and Abington offices we cover the full Route 93 corridor down to the Bourne Bridge. Click your town for local service details.

    Quincy
    Navien service in Quincy
    Abington
    Navien service in Abington
    Braintree
    Navien service in Braintree
    Weymouth
    Navien service in Weymouth
    Milton
    Navien service in Milton
    Hingham
    Navien service in Hingham
    Hanover
    Navien service in Hanover
    Rockland
    Navien service in Rockland
    Scituate
    Navien service in Scituate
    Cohasset
    Navien service in Cohasset
    Marshfield
    Navien service in Marshfield
    Plymouth
    Navien service in Plymouth
    $99
    /year
    The Family Plan

    Annual Navien descaling + priority scheduling + no service fees.

    If your Navien is under long-term care with us, the annual flush and tune-up is covered under the Family Plan. One visit pays for the year.

    Common Questions About Navien Service

    How much does a Navien tankless water heater cost installed on the South Shore?
    Installed pricing depends on the model (NPE-S2 vs NPE-A2 vs a combi NCB/NFB), whether your gas line, venting, and electrical are already sized for a tankless, and any code upgrades the existing install missed. We charge a $99 service fee that applies toward the work, come look at the actual setup, and give you an itemized quote before touching anything. No bait pricing.
    Do you service Navien error codes like E003, E012, or E027?
    Yes. We service all current Navien residential models — NPE tankless water heaters, NCB combi boilers, and NFB high-capacity combi units. E003 is usually ignition (gas valve, flame rod, venting, or low gas pressure). E012 is flame loss during a call for hot water. E027 is a water outlet temperature sensor fault. We'll diagnose the root cause, not just clear the code and hope.
    Is a Navien tankless actually worth it in a Massachusetts home?
    For most South Shore homes with natural gas and a growing or heavy hot water demand, yes. Benefits: endless hot water, 30–50% less gas use vs a storage tank, 20+ year lifespan, and they free up floor space. Caveats: your gas line may need to be upsized, venting must be done right, and incoming groundwater here is cold (38–45°F in winter) so sizing is critical. We size for your actual fixture count and worst-case winter inlet temperature.
    Can you replace my existing tank water heater with a Navien tankless?
    Usually yes. The conversion typically involves a new dedicated gas line (or upsized existing), stainless concentric or PVC venting to an approved exterior termination, a condensate drain, a 120V outlet, and a permit pulled with the local inspector. We walk the install with you first so there are no surprises. If the jump to tankless does not make sense for your house or budget, we will tell you.
    Do Navien tankless units qualify for Mass Save rebates?
    Some high-efficiency gas tankless water heaters and heat pump water heaters qualify for current Mass Save rebates — the programs and amounts change periodically, so we point you to the live Mass Save details and install qualifying equipment. See our Mass Save page for the current rebate status.
    How often does a Navien tankless need maintenance?
    Annual service — descale the heat exchanger (flush with a pump and cleaning solution), clean the inlet water filter, inspect the flame rod and condensate trap, and confirm combustion is in spec. In hard water areas, descaling may be needed more often. Skipping this is the #1 reason tankless units fail early.
    Where can I buy a Navien on the South Shore?
    Navien is sold through licensed plumbing and heating pros, not big-box stores. We supply, install, and register the warranty for Navien units we put in, and we pull the required Massachusetts permit so the installation is inspected and recorded properly. If you already have a unit on-site, we can still install it — just know the warranty terms vary when equipment isn't supplied by the installing contractor.
    Local trust + next step

    Why South Shore homeowners choose Johnson Bros.

    Family-owned and local
    Serving Quincy, Abington, and the South Shore.
    Licensed and insured
    MA Master Plumber License PL #17034-M with insured work and professional standards.
    Clear service path
    We'll review your request and confirm the next available appointment.

    Got a Navien issue — or thinking about installing one?

    If it's throwing an error code or leaking, call so we can tell you whether this is an emergency visit or a standard diagnostic. If you're planning an upgrade, book and we will review the install with you on-site before any work is quoted.

    Call About a NavienBook Navien Service

    Need help fast? Call for urgent plumbing issues. Booking online is best when you want the next open appointment without waiting on the phone.

    Areas we serve
    QuincyBraintreeWeymouthHinghamPlymouthMarshfieldScituateAbington

    Related services

    Tankless Water Heater Guide

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    Water Heater Service

    Tank repair, replacement, and install if tankless is not the right fit.

    Heating & Boiler Service

    Licensed gas fitting and heating system work for Navien combi installs.

    Got a Navien issue — or thinking about installing one?

    If it's throwing an error code or leaking, call so we can tell you whether this is an emergency visit or a standard diagnostic. If you're planning an upgrade, book and we will review the install with you on-site before any work is quoted.

    Call About a NavienBook Navien Service

    Call for urgent help now. Book online when you want the next available fit for your schedule.