Troubleshooting

Observe the green LED on the water heater gas con- trol. Error codes are displayed with a 3 second pause before repeating. Once the error code is known, check and repair the water heater, as recommended in the table below.

Green LED

LED Status

Control Status

 

Probable Cause

Service Procedure

None (LED

 

Control power switch in "OFF"

 

not on or

No electrical power

position.

Turn Power On

flashing)

 

Supply voltage interrupted.

 

One short

Stand-by mode,

Temperature demand is satisfied

 

flash every

Thermostat is

Normal operation

four seconds

satisfied (no faults)

(no call for heat)

 

Alternates

 

 

 

 

bright and

Thermostat calling

Tank temperature below

Normal operation

dim

for heat (no fault)

setpoint of thermostat

 

(heartbeat)

 

 

 

 

 

 

1.

Unstable pilot

 

 

 

2.

Pilot tube blocked or restricted

1. See Burner Inspection on

Short flash

Weak pilot signal

3.

Oxidation build-up on pilot

page 20

once every

electrode

2-4. See Pilot Inspection,

second

on last call for heat

4.

Wire damage to pilot

Testing and Replacement on

 

 

assembly or bad connection at

page 22

 

 

gas control

 

 

 

 

 

 

 

 

1.

Pressure switch tubing kinked

 

Two flashes,

Pressure switch not

or blocked

1-3. See Pressure Switch

three second

working-closed

2.

Blocked pressure tap on

Testing on page 25

pause

position

switch or blower

 

 

 

3.

Faulty pressure switch

 

 

 

1.

Vent blockage or improper

 

 

 

vent configuration

 

 

 

2.

Pressure switch tubing kinked

1. Check vent or vent tables

Three

Pressure switch or

or blocked

2-3. See Pressure Switch

flashes,

blower temperature

3.

Faulty pressure switch

Testing on page 25

three second

switch not working-

4.

Blower not spinning up to

4. See Blower Testing on

pause

open position

speed

page 28

5.

Blower temperature or

5-6. See blower Temperature

 

 

 

 

exhaust temperature too high

Switch Testing on page 31

 

 

6.

Faulty blower temperature

 

 

 

switch

 

Four flashes,

Excessive tank

1.

Thermal well sensor out of

1. Test Gas Control & Thermal

temperature,

Well

three second

calibration

system must be

2. Replace gas control if

pause

2.

Faulty gas control

reset

necessary

 

 

 

Five flashes,

False pilot flame

 

 

 

three second

Pilot valve stuck in open position

Replace gas control

present

pause

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Page 17

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Image 17
Bradford-White Corp U4TW60T*FRN, U4TW50T*FRN Troubleshooting, LED Status Control Status Probable Cause Service Procedure