Bradford White TW4-75S-76B-3N - Manual (Page 36)

36
TROUBLESHOOTING
LED Status Control Status Probable Cause
None (LED not on or
flashing)
Electrical power not
present.
Control power switch in “OFF” position.Supply
voltage interuppted.
One short flash every
four seconds
Stand‐by mode,
Thermostat is
satisfied (no faults).
Temperature demand is satisfied (no call for heat).
Alternates bright and
dim (Heartbeat)
Thermostat calling
for heat (no fault).
Tank temperature below set point of thermostat.
Short flash once
every second
Weak pilot signal on
last call for heat.
1. Unstable pilot.
2. Pilot tube block or restricted.
3. Oxidation build up on pilot electrode.
4. Wire damage to pilot assembly or bad
connection
at gas valve.
Short flash once
every two seconds
Idle remote
command off
1. Control put in idle or Sabbath mode from
accessory module
Two flashes, three
second pause
Pressure switch not
working‐closed
position.
1. Pressure switch tubing kinked or blocked.
2. Blocked pressure tap on switch.
3. Faulty pressure switch.
Three flashes, three
second pause
Pressure switch or
blower temperature
switch not working ‐
open position.
1. Vent blockage or improper vent configuration.
2. Pressure switch tubing kinked or blocked.
3. Blower not spinning up to speed.
4. Vent temperature too high
5. Faulty pressure switch or vent limit switch.
Four flashes, three
second pause
Excessive tank
temperature.
System must be
reset.
1. Excessive sediment
2. Hot water entering the tank from another
source in the potable loop.
3. Faulty gas valve.
Five flashes, three
second pause
False pilot flame
present.
1. Pilot valve stuck in open position.
Six flashes‐one flash,
three second pause
(Soft lockout)
Failed to light pilot.
System auto resets
after 5 minutes.
1. Unstable pilot.
2. Pilot tube blocked or restricted.
3. Oxidation build up on pilot electrode.
4. Wire damage to pilot assembly or bad
connection at gas valve.
Six flashes‐two
flashes, three second
pause (Soft lockout)
Pressure switch or
blower temperature
switch opened
during burner
operation.
System auto resets
after 5 minutes.
1. Pressure switch tubing kinked or blocked.
2. Vent blockage or improper vent configuration.
3. Vent termination being affected by windy
conditions.
4. Blower not spinning up to speed.
5. Vent temperature too high
6. Faulty pressure switch or blower temp. switch.