Hot water pressure drop

Hi Mike, I have a Pulsa coil PB180 which was installed in my flay in 2008. Last week the hot water pressure dropped. We are still getting hot water but at a much reduced pressure and the cold water pressure is fine. We live in maidenhead so happy to use your services unless there is a quick fix that we may be able to do ourselves. can you help please

Pulsacoil BP unit?
If so it must be the mixer / blending valve for the hot water.
Could be a filter.
Check on here for a local guy in your area.
Or Google up Gledhill repairs your area.
Mike