mypros+
Error code reference

Bradford White Water Heater Error Code 3 flash

Pressure switch or blower temperature switch not working in open position (failed to close).

Bradford White codesBradford White water heater codes

Pressure switch or blower temperature switch not working in open position (failed to close).

First step from the service manual

Check vent for blockage or improper configuration, check pressure switch tubing, test pressure switch, verify blower spinning to speed, check blower temp switch. See pages 19, 21, 24.

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 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 3 flash means on a Bradford White water heater

The 3 flash error code on a Bradford White water heater indicates that the pressure switch or blower temperature switch has failed to close, meaning the control board is not receiving the signal it expects to confirm proper venting system operation. These switches are normally open and are designed to close when the inducer blower creates sufficient negative pressure in the venting system. If neither switch closes within the expected timeframe during startup, the control board locks out ignition and signals the fault with three LED flashes.

The pressure switch monitors negative pressure (draft) created by the blower motor in the sealed combustion or power vent system. A blocked or improperly configured vent pipe is one of the most common triggers, as restrictions in the exhaust or intake path prevent the blower from generating adequate draft to close the switch. Damaged, disconnected, or moisture-filled pressure switch tubing can also prevent the switch from sensing actual pressure conditions. The blower temperature switch is a separate safety component that monitors heat at the blower housing and must also remain in a closed state during normal operation.

Diagnosing this code requires a systematic approach. Start by inspecting the vent system for blockages, improper pitch, excess length, or incorrect configuration. Check the rubber tubing connecting the pressure switch port to the blower housing for cracks, kinks, or water accumulation. Test the pressure switch itself for continuity and proper operation under draft. Confirm the blower motor is spinning at the correct speed, as a sluggish or failing blower may not generate sufficient pressure to actuate the switch. Finally, verify the blower temperature switch is functional and not open due to an overheat condition.

Source: manufacturer service documentation.

Common causes of 3 flash

  1. 01

    Blocked or improperly configured vent

    Wiring / connection

    A blocked, kinked, or incorrectly routed exhaust or intake vent pipe reduces draft, preventing the pressure switch from closing. Inspect the full vent run for obstructions, bird nests, ice, or configuration errors such as excess length or too many elbows.

  2. 02

    Damaged or disconnected pressure switch tubing

    Wiring / connection

    The small rubber hose connecting the pressure switch to the blower housing can crack, collapse, or fill with moisture, preventing accurate pressure sensing. Inspect the tubing for visible damage, disconnection, or water inside the line.

  3. 03

    Failed pressure switch

    Part replacement

    The pressure switch itself can fail in the open position, meaning it never closes even when adequate draft is present. Test the switch for continuity with a multimeter while the blower is running to confirm it is or is not actuating properly.

  4. 04

    Blower motor not reaching operating speed

    Part replacement

    If the inducer blower motor is failing, worn, or obstructed, it may spin too slowly to generate sufficient negative pressure to close the switch. Listen and observe the blower for unusual noise, slow rotation, or failure to start.

  5. 05

    Blower temperature switch open or failed

    Part replacement

    The blower temperature switch is a separate safety device that opens if the blower housing reaches an unsafe temperature, or can fail open due to age or heat damage. Test the switch for continuity to determine if it is the source of the fault.

See the test procedure for each cause

Frequently asked questions about 3 flash

What does 3 flash mean on a Bradford White water heater?
Three flashes on a Bradford White water heater indicate that the pressure switch or blower temperature switch did not close as expected during startup. These switches are part of the venting safety system and must confirm proper draft before the control board allows ignition. The heater will lock out and refuse to fire until the condition causing the switch to remain open is corrected.
Can I fix the 3 flash error myself?
Some causes of this error are DIY-accessible, such as clearing a blocked vent, reconnecting loose pressure switch tubing, or removing moisture from the sensing hose. Testing the pressure switch and blower motor for proper function requires a multimeter and some comfort with appliance diagnostics. Replacing components like the blower motor or pressure switch is within reach for experienced DIYers, but if you are unsure about working on gas appliances, a qualified technician should perform the repair.
Is a 3 flash error on a Bradford White water heater dangerous?
The 3 flash code is a safety lockout, which means the heater has stopped operating to prevent a potentially unsafe condition. Because this fault relates to the venting system, it should be taken seriously. A compromised vent could allow combustion byproducts to accumulate if the unit were allowed to operate unchecked. Do not attempt to bypass the lockout, and address the underlying cause before returning the unit to service.
Will resetting the water heater clear the 3 flash error?
Resetting the control board may temporarily clear the fault and allow a restart attempt, but the error will return if the underlying issue has not been resolved. The pressure switch or blower temperature switch must successfully close during the next startup sequence, or the lockout will reoccur. A reset is useful for confirming a repair was effective, but it is not a substitute for diagnosing and correcting the root cause.
How much does it cost to repair a Bradford White water heater showing a 3 flash code?
Repair costs depend on the specific cause. Clearing a vent blockage or reattaching pressure switch tubing may cost nothing beyond your time. Replacing a pressure switch typically runs between $20 and $80 for the part, while a blower motor replacement can range from $100 to $300 or more depending on the model. Adding labor for a service technician generally brings total repair costs to between $150 and $500 depending on the component involved and local labor rates.

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