Had this problem with my sisters back boiler a few years back found that the gas main was corroded and rust had clogged up the boiler
kokey
February 2008
try national grid. you won't get far with transco anymore. we changed hands months ago.
sid
February 2008
Possible faulty gas meter governor, as main gas lights the pilot may shrink. Simple test turn on any other gas appliance full eg cooker then turn on boiler when pilot lit and watch gas on burners on cooker if a visable shrink then is definately gas meter governor. Call Transco who will replace for free. Good luck.