hot water flow?

Dear all
I have a potterton puma 80e combi boiler.
The hot water from the sink tap and Bath taps runs very
slowly. The bath tap is the worse.
The water flow from the cold taps is fine.
I have fitted a new scale inhibitor and cleaned the taps out.
the water is hot and the central heating works ok.
Is the boiler faulty? as the water flow from the hot taps
is only affected.
thanks