Whole House Pump - 2 or 3 Bar?

On average most mains water comes in at 3 bar so most house hold product can with stand 3 bar you may have problems on ballvalves in toilets and tap washers going from low to high pressure

Most households have very varying mains pressure inlets the max would be 3bar. However as the system is gravity hot and cold this does not effect the outlets . A pump however can only use the water stored in the loft tank,so once you start to use this at a higher rate you can run out of water . Pumps are not really an answer in 2019,your best answer is to simply change to a pressurised cylinder this is a positive step forward and the only one. Least of all the noise from a ou mp in the middle od the night.

3bar is fine, the one I mostly come across 👍

If you are on a gravity system (vented with a cold water storage tank in the attic) a whole house pump is not going to improve your domestic hot water pressure, only the cold side. Your hot water pressure is dictated by the vertical distance from the bottom of the cold water tank (outlet) to whichever outlet (tap/shower) you are using. You develop 0.1 bar of pressure for each vertical meter (basically) and the pump will only fill this tank faster, it creates no extra pressure. if you have an unvented cylinder installed or change to a combi boiler you will be able to increase the pressure and flow by using a whole house pump but most people do not find this necessary in practice. Hope this helps save you from wasting money. Nige, Trust Plumbing Scarborough