A.O. Smith GWV - 120 Installation And Service Manual page 79

Code + description Cause
F03 (lock out error) Damaged wiring/Open
circuit
The pressure switch
fails to work correctly
Pressure switch not
closing
Instruction manual GWV
Measures to take
1. Check the wiring between the pressure switch and the
controller
2. If necessary, replace the wiring
1. Check the running speed of the fan
appliance selection")
2. Check that the hoses are fitted correctly to the pressure switch
and the ventilator's air supply hose. Refit them if necessary
3. Check for cracks in the hoses on the pressure switch and in the
air supply hose for the fan. If necessary, replace the hoses.
4. Check that the flue gas outlet is compliant
flue").
5. Measure the pressure differential across the pressure switch.
See the table (2.4.5 "Pressure switch"). If there is insufficient
pressure difference, clean the heat exchanger. If the pressure
differential is acceptable, check that the pressure switch is
closing, using a multimeter.
Comment
If the error cannot be resolved or is persistent, contact your
installation engineer
To replace the necessary parts, you must contact your installation
engineer
(12.5 "Displaying the
(3.9 "Air supply and
is
79