vaillant hot water problem

[willow123]

hello
my boiler is a seven year old vaillant 824e.
the heating works fine ,but the hot water is normal temp downstairs(in kitchen)but only gets lukewarm in the bathroom (upstairs).the boiler is located upstairs in front bedroom.I have no fault codes showing,any help would be appreciated thx.

 

[gavinda]

which taps upstairs are no good...

 

[willow123]

both the bath and sink taps are producing lukewarm water,the hot water control on the boiler is about three quarters way round and temperature indicated by boiler display is 75degrees