Worcester Bosch highflow 400 rsf

Next door calls me, no HW or CH can I have a look. See no pressure, so open filling loop. Obvious leak . Dentists mirror seems to confirm leak when trying to filll either lower manifold or uppper one running down. Cannot hold pressure. In fact major breach as running down walls and tripping lights. Have isolated fault but odd thing is notice when trying to re-pressurise sys the leak seems to come from behind the Diverter valve.

Is this common or just a seal.

Can't get a reliable chap to sort it out until Tuesday but 13 month old baby and 2 year old have no heat or hot water.

Can repair but I refuse to touch gas.

Downloaded parts manual but as can't determine exact root cause of leak.

Has to be upper of lower manifold which seems to be plastic.

Replacement seems routine.

Degree of leak suggests split in a manifold as apart from the o rings giving way.

All systems isolated and being dried out.

well the diverter has three o-rings behind it, one of which is very thin.

TBH everything is so close on the hiflow its hard to tell one leak from another sometimes.

If there is water above the lower manifold then I would sugest the upper one leaking, possibly a seal, possibly a crack, impossible to tell without seeing it.

any manifold top or bottom is a complete nightmare to do ,if you fancy it make sute you have the full o ring kit