Walk in shower

[Madrab]

Yup, you need a pressure gauge, attached to an outside tap or appliance valve. No water running - Static Pressure - water running - Dynamic Pressure. I would hope your plumber would have one.
A rough guide would be to turn the hot water on full, get it hot, then turn on the cold, does the hot water drop in delivery?

 

[Steelmasons]

Yes you can, it is specifically designed for this purpose. The manufacturers specification states "Boosts the incoming mains pressure to combi boilers" I think you are confusing it with a pump designed for stored hot water which is a different beast.

Some boilers are not compatible when using booster pumps on the incoming supply....CO will go through the roof due to rapid burner modulation.

 

[Aquaheat]

Some boilers are not compatible when using booster pumps on the incoming supply....CO will go through the roof due to rapid burner modulation.

Which boilers Steel? How does it affect them? Ive never fitted a mains booster pump but this would be useful info. How is it different from having 10lpm to 12lpm? What screws up the modulation? Surely it would only be the same as having 12lpm as standard? What am I missing?

Jon