Bradford White UDH-75T-50FR-3N - Manual (Page 4)

4
Honeywell Gas Control Troubleshooting Chart
LED Status Control Status Probable Cause
None (LED not on or
flashing
Pilot assembly is not lit
1. If set point knob is in “PILOT”
position then pilot flame is detected.
Turn set point knob to desired setting.
2. If the set point knob is already at
the desired setting, the water heater is
satisfied.
One flash and three
second pause
Two quick flashes
and a three second
pause
Gas control is calling for heat (no
fault).
Two flashes and
three second pause
Weak pilot signal detected. System will
reset when pilot flame is sufficient.
.
Gas Control is not powered. Light pilot.
1. Gas Control is powered and waiting
for the set point knob to be turned to a
water temperature setting.
2. Water heater is satisfied and
operating normally.
Tank temperature below set point of
thermostat.
1. Thermopile failure
2. Unstable pilot
3. Pilot tube block or restricted.
Service
Procedure
If the pilot will not stay
lit replace pilot
assembly. If problem
persists replace Gas
Control.
1. Adjust set point knob
to desired setting.
Normal operation.
1. See service
procedure II
2. See service
procedure III
3. See service
procedure III
Flammable Vapor Ignition Resistant Water
Heaters
Green LED Indicator
Observe green LED indicator on
Gas Control. Error flash codes are
displayed with a three second pause
before repeating. Check and repair
the system as noted in the
troubleshooting table below.
Four flashes and
three second pause
Excessive tank temperature. System
must be reset.
1. Temperature sensor out of
calibration
2. Faulty Gas Control
1. See service
procedure V
2. See service
procedure V
4
LED on continuously
(Solid)
Set point knob has been recently
turned to the “OFF” position. Wait
until LED goes out before
attempting to relight
Set point knob was turned to “OFF”
position.
LED will go out and the
control will function
normally when the pilot
is lit.