Low hot water pressure - Old Boiler Suprima HE

We just moved to a new property and until we can save a bit more we will need to continue using the old boiler.

The current hot water pressure is extremely low (cold water pressure is great) and is annoying specially when having a shower and I am not sure if there is any setting we can change in the boiler to increase the pressure (safely).

In the next 6 months we plan to upgrade to a combi boiler but until then we are looking for a low cost solution to increase the hot water pressure.

Boiler model Suprima HE from Potterton, pictures below