They have been and this time figured out that some part had gone it.
They returned next day with tha part (SW Stat??) - a little cumbell
type device with 2 long leads. They installed this part and the pilot
came back on and stayed on. They left.

However, the old problem still exists - when using hot water, it keeps
going out every 4-5 mins and the pilot has to be re-lighted.

Also they said that the bolier is on a reduced parts list - they cant
get all the parts for it. Its a Wrcester combi bought in 1996.