Leaking boiler

[rayo]

leaking isra m30100 boiler one of the pipes which fits to the pump
Ive tryed to get new O rings from my plumb centre but with no luck
isra (ideal ) dont seem to know what Im on about Ive discribed what,where but have no luck anyone out their any ideas.
Its getting to be a pain having to empty the bowl.
Or does anyone have a diagram of the part with part nos

 

[LUNAT]

HI

in the past i used different type of washer fo the pump connections.try the closest .

 

[rayo]

Have tryed several types but none seem to be thick all seem too thin have tryed putting a thin washer on as well but the original o ring has gone hard