can u please help me. i am still having problems with my vaillant boiler which the plumber has failed to leave me any instructions for. again it still displays f28 when i try to switch the heating or water on via the dials on the front of the boiler. i have switched the power off at both the socket and on the front of the boiler and have tried turning them back on and turning the dial to turn on the heating and water but the display first shows the degrees then f28 and the pilot light still fails to come on although it does sound like it is attempting to fire up. any further help would be grately appreciated

k wallace, February 2009

make sure you have gas (check there is credit on meter and is "on" if you have a pre-pay meter, also check it hasn't been turned off at the meter contol, (the on off lever)), next you need to press the the reset button on the boiler which is the top left hand of the four small grey buttons on the front panel, (the one with a picture of a flame with a cross through it), if it still doesn't fire up you need an engineer.

tojo, February 2009

F.28 Appliance does not start: Attempts to ignite during start
failed
Faults in the gas supply such as:
- Gas meter or gas pressure detector defective
- Air in gas
- Gas flow pressure too low
- Fire protection tap has disengaged
Faults in the gas valve, wrong gas setting, igniter (ignition transformer,
ignition cable, ignition plug) defective, ionisation current
stopped (cable, electrode), faulty earthing in appliance, electronics
defective
F.29 Flame goes off during operation and subsequent ignition
attempts failed
Gas supply temporarily stopped, faulty earthing of appliance

a, February 2009