Main combi 30 HE no hot water upstairs ?

I can only get hot water if my tap is full on and upstairs bathroom dont get any hot water,

But the central heating is fine and when turned on i get hot water all round up stairs and down ?

I have recently bled heaters and then repressured the boiler to 0.75 . (also tried 1.5 still same.)

ive not left the filling loop on either.

flame failure light is on too and will not go if i reset (solid light not flashing)

ive checked the condenser pipe too does not seem frozen

??? any ideas