Hi bengerman
The standard mains pressure to the boiler seems to too high to allow the water passing through it to heat up at appropriate rate to give a hot a bath in a reasonable time (1st.floor).S.
Problem is as described... the cold water flowrate through the house is too great for the boiler to heat to "bath" temperature - which is around 50-60 degrees C...
Takes ages to fill ..before we moved into this house ,a roof extension was added by the previous owner which extended the CH and...