Pilot light won't stay lit - Baxi wm50 4rs

[Belzok]

The pilot light on my Baxi wm50 went out over night sometime and I can't get it to stay relit.

I held down the selector knob on the spark setting and the pilot lights no problems and I can see the flame being drawn to the right. I have kept the button depressed for about a minute before letting go at which point the pilot goes out.

The instruction manaul mentions reseting a thermal cutout switch which is around the back of the control box apparently. I have had the front off and felt around the back of both the valve assembly and the box that has the temperature setting on it and can't find it, can anyone confirm where exactly where it is as my tank is infront of the boiler and I can't get at it to peek around the back

 

[gas4you]

More likely the thermocouple needs replacing.

 

[Belzok]

Thanks, I had thought this may well be the case but I didn't want to call someone out just to reset the cutout switch if at all possible.