Navien Error 003: what it means and what to do
Error 003 means your tankless water heater tried to light and couldn’t, so it shut itself off and you’ve got no hot water. This is the screen we walked up to in a Northern Virginia basement.
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From one of our jobs
Error 003 on the display: the burner never lit
Right now: Write the code down, check that your other gas appliances work, then reset the unit once.
Every time you open a hot tap, the heater sparks the burner and watches for a flame. No flame after a few tries and it stops, shows 003 and waits. Most of the time it’s gas not getting there: a valve turned off, a propane tank running low, or a gas line too small for the heater. The rest is the heater itself: a dirty igniter or flame rod, or a vent or condensate line that’s blocked.
Turn the heater’s power off and back on once. If hot water comes back and stays, keep an eye on it. If 003 comes back, that’s a repair, not a reset, and we fix tankless heaters every week.
Quick answers
What people ask about Navien Error 003
What does Error 003 mean on a Navien?
Ignition failure. The heater tried to light the burner, didn’t see a flame and shut down so it doesn’t keep sending gas. You’ll have no hot water until it lights.
Why is my tankless water heater showing 003?
Usually gas: the valve to the heater is partly closed, a propane tank is low, or the gas line can’t feed the heater when the furnace runs too. Less often it’s a dirty flame rod, a worn igniter, or a blocked vent or condensate line.
Can I reset Error 003 myself?
Once. Turn the power off at the switch or plug, wait a moment and turn it back on. If it lights and stays lit, you’re fine for now. If 003 comes back, stop resetting it and call.
Is Error 003 dangerous?
The heater shutting off is the safe part. If you smell gas, leave the house and call your gas company from outside, then us.
Who do I call for a Navien error code in Northern Virginia?
Call SwiftPro at (703) 997-9757. Our plumbers fix and install tankless water heaters across Northern Virginia, and we’ll tell you whether yours is worth fixing before we touch it.
Seeing this at your house?
Tell us what you’re seeing. We’ll tell you what it is and what the fix costs, in writing.
What it costs
What we charge to replace a tankless water heater
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SwiftPro Heating, Cooling & Plumbing
4230 Lafayette Center Dr N, Chantilly, VA 20151
44679 Endicott Dr, Suite 211, Ashburn, VA 20147
SwiftPro Plumber & Water Heaters
4200 Lafayette Center Dr, Suite N, Chantilly, VA 20151
Virginia Class A contractor license #2705192276