No it will not make any difference at all. The only way to boost the presure is to install a tank in the loft so that you can then fit a suitable pump to feed an electric shower. How ever how do you know that you have low water pressure for sure & have you tested it ? It may be that you're boiler is not big enough and there is nothing wrong with the pressure. The local water athority has to deliver a minimum water pressure of 1.5 bar to its customers, so if it is below this it needs reporting to them and they will have to sort it out.