A.O. Smith SGS - 100, Installation, User And Service Manual

Page: 97 / 121

is
Instruction manual SGS 94
F04 (lock out error)
Three unsuccessful
ignition attempts.
No gas 1. Open the main gas supply valve and/or the manual gas supply
valve before the gas control valve
2. Check supply pressure to the gas control valve
3. If necessary, restore the gas supply
To restore the gas supply, contact your installation engineer
Air in the gas pipes Bleed the air out of the gas pipe (3.13 "Check the supply pressure,
gas control valve pressure, CO
2
value and switching pressure")
See Checking the supply pressure and burner
pressure (3.13 "Check the supply pressure, gas control valve
pressure, CO
2
value and switching pressure") for how to bleed air
from the gas line and how to measure the supply pressure and
burner pressure.
To replace the necessary parts, you must contact your installation
engineer
Defect in the hot
surface igniter circuit
1. Check that the hot surface igniter is correctly connected (JP2).
2. Check the wiring of the hot surface igniter.
3. Measure the resistance across the hot surface igniter. This must
lie between 2 and 10 Ohm (at room temperature).
4. Check that the hot surface igniter lights up during ignition.
5. If necessary, replace the hot surface igniter.
If the error persists, contact your installation engineer.
To replace the necessary parts, you must contact your installation
engineer
Defect in the ionisation
circuit
1. Check that the flame probe is correctly connected (JP2)
2. Check the wiring of the flame probe
3. Measure the ionisation current. This must be a minimum of
1.5 microA.
4. If necessary, replace the wiring.
Supply voltage too low Check the supply voltage, this must be 230 V
AC
(-15%, +10%)
F05 (lock out error)
Too many flame errors
have been signalled.
Incorrect roof or wall
flue terminal.
Recirculating flue
gases.
1. Check that the correct roof or wall flue terminal has been
installed (3.10 "Air supply and chimney flue discharge").
2. If necessary, install the correct roof or wall flue terminal.
3. Check that the roof or wall flue terminal discharges into a
permitted area.
If the error cannot be resolved or is persistent, contact your
installation engineer
Code + description Cause Measure Remark