Vaillant Turbomax Vuw 242E, 282E

[Safc]

My Vaillant 242E is experiencing an unusual problem. The boiler is working outside of it's timer. I have recently fitted a new Siemens timer. For example the timer switched off at 9.00am but the boiler still fires up and is heating the radiators. Any ideas as to what this problem could be?

Thanks
Ian

 

[ChrisR]

DIverter valve sticking open - water may be in the switch on its right hand side.
You would also find that the CH pipes get hot when HW is being drawn.

 

[namsag]

You would not be the first to have set the clock wrong AM instead of PM so check settings.. After that as heating is the rest position of the boiler if the hot water microswitch on divertor is stuck this will give you heating when you don`t want it. I t is on a push in connector disconnect it and if heating goes off you know it is the switch