vaillant thermo compact wont ignite

[al-m]

awaiting appointment some time when. meanwhile boiler wont ignite, comes up with code 33
has done this 2 evenings on trot, worked fine all day

 

[chrishutt]

Look in the manual to see what "33" means. If you don't have a manual let us know the model number of the boiler and we might be able to help.

 

[al-m]

hi chris

previous home owner didnt leave manual

written inside case is

thermo compact plus 628E
and
GB 282/2-5

 

[chrishutt]

Here is the manual.

 

[al-m]

many thanks chris

 

[ollski]

check d.24 in diagnostic mode when its playing up, will guess it comes up zero and points to another faulty air pressure switch.

 

[chrishutt]

Fault code F33 also points to this area.

 

[ricardo111]

THE CODE S.33 (NOT F.33) IS A STATUS CODE, WHICH YOU ACCESS BY PRESSING THE i BUTTON. THIS TELLS YOU WHERE THE BOILER IS IN ITS SEQUENCE OF OPERATION. S.33 MEANS IT IS TRYING TO PROVE THE FLUE INTEGRITY (COURTESY OF THE AIR PRESSURE SWITCH) BUT DUE TO IT BEING A SQUARE BLACK ONE, IT IS PRONE TO STICKING FAULTS. I HAVE CHANGED HUNDREDS OF THE LITTLE BLIGHTERS. YOU WILL FIND SOMETIMES BY GIVING THE BOILER A LITTLE TAP AT THE BACK TOP RIGHT ,YOU CAN PERSUADE IT TO SWITCH OVER AND IT WILL FIRE. OTHERWISE REPLACE THE AIR PRESSURE SWITCH THEY ARE QUITE CHEAP AND VERY EASY TO DO PROVIDED THERE IS AT LEAST 6 INCHES CLEARANCE ABOVE THE BOILER

 

[kevplumb]

don't shout