Ok...have solved the problem...are you any good at DIY? The problem is your pilot light injector is slightly blocked and the pilot flame is not long enough and therefore not reaching the sensor which it needs to heat up in order to prevent the safety cut off from activating. You need to:
Turn off the gas supply to the heater.
Remove the 2 plastic knobs [pull off]
Undo the two screws on the bottom of the outer casing.
Remove outer casing.
On the right of the inner casing, you will see 3 inlets to the fire, The nearest to you is the pilot light.
Unscrew the nut which holds it in.
Gently pull away from fire.
Strip the plastic from a bread wrapper tie and give it a good poking around the jet to clean.
Refit pilot light.
You need to check the joint is gas tight...turn on the gas to the heater, pour a small amount of fairy liquid on the joint, depress the ignition starter knob to release gas...watch for bubbles on the joint. If no bubbles are evident, refit the case and hey presto!
beebee
December 2008
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix home heating systems.