Open 24/7 for emergencies
A Navien tankless water heater repair starts with the $99 diagnostic, and a new Navien is $8,886 to $10,486 installed, permit and haul-away included. We install Navien, so an E003 or an E760 on the display tells us where to start.
From about $148 a month at 0% APR for 60 months, the whole price financed, on approved credit. How financing works
Get your price in writing
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Rather talk now? (703) 997-9757
5.0 stars across 1,132 reviews
Licensed and insuredVirginia Class A contractor #2705192276
24/7 emergency serviceOften same-day, and we will tell you honestly when we can get there.
Our own plumbers, our own trucksNobody here is a subcontractor with a magnet on the door
The price is settled before the workYou see the number in writing before anything is taken apart
Read your own Navien
The things people describe on the phone about a Navien, and where each one points.
Read the E-number on the display first: E003 is an ignition failure, and Navien’s first check is that the gas valve to the heater is open. No code at all points at flow: a Navien needs half a gallon a minute to fire, and Navien says the flow sensor is likely not spinning, often from debris. The cold water inlet filter gets cleaned first.
That’s the cold water sandwich: the hot water left in the pipe runs out, then a few seconds of cold while the burner fires back up. The NPE-A2 has a small buffer tank and a recirculation pump built in, which Navien calls ComfortFlow. An NPE-S2 needs an external pump to recirculate, priced once we’ve seen the piping.
Check three things on a Navien: the cold water inlet filter, scale in the heat exchanger, and the gas line. Navien allows half-inch gas pipe only up to 24 feet, and its warranty won’t cover performance problems from an undersized gas line or vent. We check the filter and the gas before anyone talks about parts.
Start with the cold water inlet filter, the small screen where the water comes in: when it clogs, everything slows. Scale building up inside the heat exchanger narrows the passages too, and that’s a descale.
E760 is Navien’s flushing and service alarm, and the manual says call your installer for routine service. Navien calls hard water scale the biggest single reason its units fail, and recommends a yearly flush in a home once the water is over 4 grains per gallon with no softener. Scale damage and skipped maintenance aren’t covered by its warranty.
Navien’s freeze protection only works with the power on, so an outage on a freezing night can freeze the heat exchanger, and Navien’s warranty doesn’t cover freeze damage. Leaking or showing a code after a cold night? Shut off the water to the heater and call before you run it.
The display
When a Navien stops, it shows an E-number on the front panel. Write it down, press the Back button once to reset, and if the code comes back, find it below.
Navien’s user manual gives an owner step for each of these.
| Code | What it means | What to do |
|---|---|---|
| E003 | Ignition failure: the burner didn’t light | Make sure the gas valve to the heater is fully open |
| E004 | False flame: the board sees a flame that isn’t there | Make sure the power cord is properly grounded |
| E012 | Flame loss: it lit, then went out | Clean the intake air filter; check the cord is grounded |
| E016 | The heat exchanger is overheating | Clean the cold water inlet filter; the heat exchanger needs a flush |
| E030 | Exhaust overheating: it shuts down when the flue passes 149°F | Clean the cold water inlet filter; the heat exchanger needs a flush |
| E109 | The fan motor isn’t running right | Clean the intake air filter |
| E110 | Abnormal air pressure | Clear the exhaust pipe outside and clean the intake air filter, which Navien says to do every 3 to 4 months |
| E515 | Control board fault | Check the cord is grounded; if it stays, the board needs a look |
| E760 | Flushing and service alarm | It’s due for routine service: Navien says call your installer |
Source: Navien NPE-2 User’s Information Manual. Codes vary by model and control board: the chart printed on your unit, or its manual, is the final word.
For each of these, Navien’s manual says contact its technical support, and Navien points owners to their installer for the repair.
| Code | What it means | What to do |
|---|---|---|
| E031 | The burner is overheating | Leave it off and call |
| E047 | Exhaust temperature sensor open or shorted | A sensor or wiring repair |
| E407 | Hot water outlet temperature sensor open or shorted | A sensor or wiring repair |
| E421 | Cold water inlet temperature sensor open or shorted | A sensor or wiring repair |
| E434 | The water adjustment valve isn’t working right | A valve repair |
| E439 | The flow sensor isn’t working right | A flow sensor cleaning or replacement |
| E445 | The bypass mixing valve isn’t working right | A valve repair |
| E762 | The vent pipe isn’t fully inserted | Leave it off and call: the venting gets reseated |
| E773 | It’s running on the wrong gas | Leave it off and call |
| E788 | The gas type set on the board doesn’t match the panel | Call: both get set to the gas you have |
Source: Navien NPE-2 User’s Information Manual. Codes vary by model and control board: the chart printed on your unit, or its manual, is the final word.
What it costs
A repair is priced after the $99 diagnostic, because the fix depends on which part failed. A new tankless water heater is a range we can print, everything in.
Diagnostic visit
$99
The code read, the fault found, and the repair priced in writing. You approve it or you don’t.
A new Navien tankless
$8,886 to $10,486
or $148/mo at 0% APR for 60 months
One condensing tankless water heater, sized for the house. The permit and haul-away included.
Monthly figures: 60mo @ 0% APR on each starting price, the whole price financed, on approved credit. Longer plans lower the payment and cost more in total. The lender sets the final terms. How financing works
The yearly descale is its own visit: tankless water heater descaling. Comfort+ members get the $99 diagnostic included in the visit, 15% off any service, and 50% of each repair bill banked toward replacing that system, up to $1,500. How Comfort+ works.
Fix it or replace it
The build date is on the rating plate on the side of the heater. On many recent units the serial number carries it too.
On many recent Navien units, the date sits inside the serial number: two digits for the year, one for the month (X is October), then two for the day. CPSC’s 2018 recall notice gives the example: 18709 is July 9, 2018. Navien doesn’t publish one rule for every model, and older labels print the full date, year first, so if the serial doesn’t fit, read the rating plate.
Navien says its tankless water heaters can last up to 20 years, and only with proper maintenance (Navien).
Gas or propane tank instead
$3,379 to $5,485
or $56/mo at 0% APR for 60 months
50 or 75 gallon on a flue you already have. Installed.
Power vent tank instead
$5,957 to $7,494
or $99/mo at 0% APR for 60 months
Gas or propane, a fan and PVC out a side wall. Installed.
Electric tank instead
$2,757 to $5,493
or $46/mo at 0% APR for 60 months
50 or 80 gallon. No flue, no gas line.
Monthly figures: 60mo @ 0% APR on each starting price, the whole price financed, on approved credit. Longer plans lower the payment and cost more in total. The lender sets the final terms. How financing works
Want your own number before anyone comes out? The water heater estimator prices your house in a few questions.
A Navien tankless water heater we installed in a Northern Virginia basement, with the condensate trap and gas line run to it.
Why we install Navien
Navien’s condensing tankless water heaters come with a pump or without one.
The warranty
The install date and how it’s set up decide it.
Registering isn’t a stated condition of the base warranty, but Navien’s tech support won’t ship parts to an unregistered unit. We read the serial and the install date before ordering anything. Navien’s terms: the NPE-2 warranty.
What customers said
5.0 stars across 1,132 reviews. Left on Google in August.
I am very happy with the service I received in installing my water heater. Tyson and the crew were very kind and cleaned everything up before they left. I would really recommend this company.
A water heater installed
Reviews are shown as customers wrote them, cut to the part about the job. Read them all.
Where we work
Out of Chantilly and Ashburn, across six counties. Pick your town for its own water heater page: the houses there, the county’s permit rules, and the same prices.
Keep reading
Every make we work on, in one place: the brands we repair.
The system we put in first
Built to take a beating. Put in by our crew.
Heat lamps, snow and rain on one outdoor unit: that’s Trane’s own film. We’re a Trane Comfort Specialist, on Trane’s own dealer locator, and when you pick a Trane, our crew puts it in.
Films: Trane’s own.
Asked on the phone
A repair starts with the $99 diagnostic: we read the code, find the part, and price the fix in writing before any work. A new Navien tankless is $8,886 to $10,486 installed, everything in, and going back to a gas tank is $3,379 to $5,485. From about $56 a month at 0% APR for 60 months, the whole price financed, on approved credit. How financing works
E003 is an ignition failure: the burner tried to light and didn’t. Navien’s first check is that the gas valve to the heater is fully open. Press Back to reset it once; if E003 comes back, call, because the fault is between the gas supply and the burner.
It’s Navien’s flushing and service alarm: the heater is due for routine service, and the manual says call your installer. On water over 4 grains per gallon with no softener, Navien wants the heat exchanger flushed every year.
On an NCB-H combi-boiler, E777 is the low water cutoff: the heating loop is low on water. Navien says check the system’s water level and add make-up water, and the cold fill pressure has to be at least 12 psi. E352 is the opposite, high pressure on the heating side, and that one’s a call.
Yes. We install Navien and Rinnai tankless water heaters, and Rheem, A. O. Smith and Bradford White tanks. We also repair a Navien someone else put in. If it’s under warranty, Navien sends claims to the original installer first, and to any licensed pro if that installer is gone.
Navien says up to 20 years, and only with proper maintenance. Scale is the biggest single reason its units fail, in Navien’s own words, so the yearly descale on hard water is what gets you there. Our guide to tankless water heater maintenance walks through it.
Get the hot water back
No hot water or a code that won’t clear: call (703) 997-9757, 24/7. Not that urgent? Send the form at the top with the code from the display, and the office calls or texts you back.
SwiftPro Heating, Cooling & Plumbing
4230 Lafayette Center Dr N, Chantilly, VA 20151
44679 Endicott Dr, Suite 211, Ashburn, VA 20147
Virginia Class A contractor license #2705192276
Prices are SwiftPro’s installed ranges with the permit and haul-away. Yours is quoted in writing before any work.
Navien, ComfortFlow and PeakFlow are trademarks of Navien.