Ideal RS40 Pilot Light

[Contax]

Just bought Bungalow, Ideal Classis RS40 pilot light gives flash of flame on ignition but only for split second even with valve held in, was working 3 months ago when gas turned off at meter, any ideas please?

 

[croydoncorgi]

Poosible that air has got into the gas pipes.
Hold the button on the gas valve in the 'lighting' position for AT LEAST 30 seconds, pressing the igniter at intervals.

 

[Contax]

Thanks croydoncorgi, I removed the gas bleed screw for a couple of minutes and have held button in for longer periods but no change, have been told to undo main gas input to give good bleed for air lock, another told me thermocouple gone but Ideal help line said not thermocouple most likeky to be air in pipe.
Any more suggestions please.

 

[PEDANTICVINDICTIVEMAN]

If not air, cr*p fallen into pilot jet or dirt got into gas valve and blocking pilot outlet inside.

 

[Contax]

I purged gas at valve then pilot stayed lit while valve held in but but jummpy flame, after many goes pilot flame size increased and was steady, boiler now started, must have been air in gas line but also dirt fallen in pilot restricting flame.
Thanks to all.