how to fix my main mersey super multipoint?

the water comes out lukewarm/cold the burners are all on can anyone help
steve H, December 2008


done
pilot light stays on but water no hot water

kirran, September 2009
Probably the diaphragm inside the water housing as they perish.Could be the rod sticking that connects the gas burner to the water housing.Just make sure no-one has knocked the main gas tap handle to nearly off as it sounds daft but it happens.

Tony S, December 2008