vaillant turbomax flame indicator light on permanently

[ibw]

hello all
new to the forum and ? anyone can point me in the right direction
I'm wondering if this is the PCB that is on its way out , the boiler is about 19 yrs old so i can't complain
the flame indicator light stays on after you have either hot water or the heating on , this appears to then lock out either function coming back on again when you call for heat, although the fan will come on.
switching off the power for a short time doesn't help, but if the power is off for longer ie 1hr+ then all works again fine.
it is intermittent problem at present but does seem to be becoming more frequent
cheers ian

 

[Agile]

I am wondering if your gas valve is sticking on which is potentially dangerous.

Identify the gas inlet valve under the boiler and the next time it happens turn the valve off and see if the light goes off.