mypros+
Error code reference

Bradford White Water Heater Error Code 6-3 flash

Pilot flame extinguished during run

Bradford White codesBradford White water heater codes

Pilot flame extinguished during run. System auto resets after 5 minutes.

First step from the service manual

Inspect pilot (page 18): check for unstable pilot, blocked/restricted pilot tube, oxidation on electrode, wire damage, insufficient combustion air, or gas pressure out of specification (page 25).

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

MyPros+ Max

Get the full diagnostic procedure for 6-3 flash.

  • Step-by-step tests with expected resistance, voltage, and continuity values
  • Wiring diagram references and connector pinouts from the OEM service manual
  • Verified part numbers when replacement is required
Get the full procedure

$29/month · Cancel anytime · Or $9.95 3-day pass

What 6-3 flash means on a Bradford White water heater

The Bradford White 6-3 flash error code indicates that the pilot flame was extinguished while the water heater was actively running. This is distinct from a failure to ignite during startup. The pilot monitoring system detected a loss of flame signal mid-operation, triggering the fault. The system is designed to auto-reset after a 5-minute delay, after which it will attempt to re-establish the pilot and resume normal operation.

The flame sensing circuit relies on the pilot electrode to detect a continuous flame signal. If the flame signal drops below the threshold during operation, the control board logs the 6-3 fault. Common causes include an unstable pilot flame, a blocked or restricted pilot tube that reduces gas flow to the pilot burner, oxidation buildup on the electrode tip that weakens the flame signal, and damaged or corroded wiring in the sensor circuit. Insufficient combustion air reaching the burner compartment can also cause the pilot to extinguish under load.

Gas supply pressure should be checked against the specification range listed on page 25 of the technical documentation. Pressure that is too low or fluctuates outside the acceptable range will cause the pilot to fail during run cycles. Begin diagnosis by closely inspecting the pilot assembly as outlined on page 18, checking electrode condition, tube routing and cleanliness, wire integrity, and ventilation to the combustion chamber.

Source: manufacturer service documentation.

Common causes of 6-3 flash

  1. 01

    Blocked or Restricted Pilot Tube

    Wiring / connection

    Debris, spider webs, or sediment inside the pilot tube reduces gas flow to the pilot burner, causing the flame to become weak and extinguish during operation. Inspect the pilot tube orifice for obstructions and clean carefully with compressed air.

  2. 02

    Oxidation on the Flame Sensing Electrode

    Part replacement

    Oxidation or carbon buildup on the electrode tip increases electrical resistance and weakens the flame signal returned to the control board. The electrode tip should be inspected and gently cleaned or replaced if heavily oxidized.

  3. 03

    Insufficient Combustion Air

    Wiring / connection

    A lack of adequate combustion air supply to the burner compartment can cause the pilot flame to become unstable or go out during a run cycle. Check that combustion air vents and the area around the water heater are clear of obstructions.

  4. 04

    Gas Pressure Out of Specification

    Wiring / connection

    Supply gas pressure that is too low or fluctuating outside the specified range will starve the pilot of fuel mid-cycle. Pressure should be measured and compared against the values on page 25 of the technical documentation.

  5. 05

    Damaged or Corroded Wiring

    Part replacement

    Wiring between the pilot electrode and the control board can develop cracks, corrosion, or loose connections that interrupt the flame signal. Inspect all wiring and connectors in the pilot circuit for visible damage or corrosion.

See the test procedure for each cause

Frequently asked questions about 6-3 flash

What does 6-3 flash mean on a Bradford White water heater?
The 6-3 flash code means the pilot flame went out while the water heater was in the middle of a run cycle. The unit detected the loss of flame signal and shut down as a safety measure. The system is programmed to automatically reset and retry after a 5-minute delay. If the fault repeats, a physical cause such as a blocked pilot tube, electrode issue, or gas pressure problem needs to be identified and corrected.
Will the Bradford White water heater fix itself after a 6-3 flash error?
The water heater is designed to auto-reset after 5 minutes and attempt to relight the pilot. If the underlying cause is a one-time event such as a brief gas supply interruption, the unit may recover on its own. However, if the 6-3 fault repeats across multiple cycles, a physical problem with the pilot assembly, gas pressure, combustion air supply, or wiring is likely present and requires hands-on inspection.
Is a 6-3 flash error on a Bradford White water heater dangerous?
The 6-3 code represents a safety shutdown triggered by flame loss, which is the control system working as intended. The heater stops operation rather than allowing unburned gas to accumulate. However, if the pilot fails repeatedly or you smell gas near the unit, do not attempt to restart the heater and contact a qualified technician or your gas utility immediately.
How much does it cost to repair a Bradford White 6-3 flash error?
Repair costs vary depending on the root cause. Cleaning a blocked pilot tube or improving combustion air access may cost little to nothing beyond a service call fee, which typically ranges from $75 to $150. Replacing a faulty pilot electrode or damaged wiring harness will add parts costs, generally in the $20 to $80 range for components, with total repair costs typically falling between $100 and $300 depending on labor rates in your area.
Can I reset a Bradford White 6-3 flash error myself?
The unit resets itself automatically after 5 minutes, so no manual reset action is required for the initial recovery attempt. If you want to inspect the pilot yourself, check for visible debris around the pilot tube, ensure the area around the water heater has adequate ventilation, and look for any obviously damaged wiring. Gas pressure testing and electrode replacement are best performed by a qualified technician with the proper tools and training.

Related Bradford White water heater codes

All Bradford White water heater codes
View all 98 Bradford White water heater codes

78,000+ service manuals · 160,000+ error codes · 55+ brands

Get Started

$29/month · Cancel anytime · Or $9.95 3-day pass