Reduced power from Mitsubishi water pump
Hopefully I've got the right forum. Apologies if not. I've got a typical 1 story house setup. Water tank, water pump with a self contained pressure tank on the bottom. I replaced a Hitachi 150 W pump with a Mitsubishi WP 155Q5. The pressure is low - maybe 70% of the Hitachi. The contractor seemed to know what he was doing but I'd like to check myself. He spent some time with the instruction sheet, showed me a spring that he said was better left out - seemed to indicate to only use it if I was pumping from a well, and I saw him making some adjustments with a screwdriver but could not see exactly where.
I'd like confirmation on the spring thing, info on how to check the pressure adjustment, and of course any other constructive ideas.