is
Release R.1.3 UK 76
Warning
Maintenance may only be performed by a qualified service and maintenance engineer.
F03 (lock out error)
The pressure switch
fails to work correctly.
Damaged wiring /
Open circuit
1. Check the wiring between the pressure switch and the
controller.
2. If necessary, replace the wiring.
If the error cannot be resolved or is persistent, contact your
installer.
To replace the necessary parts, you must contact your installer.
Pressure switch not
closing.
1. Check the running speed of the fan. See ’8.7.4 Displaying
appliance specifications’.
2. Check that the hoses on the pressure switch and the air supply
hose between fan and burner are correctly fitted. Refit these if
necessary.
3. Check the hoses on the pressure switch and the air supply
hose between fan and burner for cracks. If necessary, replace
the hoses.
4. Check whether the flue gas discharge is compliant with
Tabl e 3.7.
5. Check for blockage in the flue gas discharge. Remove any
blockage that may be present.
6. Check for blockage in the condensation water discharge.
Remove any blockage that may be present.
7. Measure the pressure differential across the pressure switch.
See Tabl e 12.1 . If there is insufficient pressure differential,
clean the heat exchanger. If the pressure differential is
acceptable, check that the pressure switch is closing, using a
multimeter.
Table10.2 Displayed errors (Sheet 4 of 10)
Code + Description Possible cause Solution Remark