Turning the speed down from 3 to 2 will help a lot with the noise, but like said before it depends on the size of the pipework, and amount of pipe. It is quite common to get a noise like a harrier jump jet taking off with a grundfos pump set to speed 3, when the heating switches on! Also, you can help the radiators all getting hot regardless of the length of the runs by making sure that they are all correctly balanced. This invloves removing the plastic valve top on the side of the radiator that has the valve that seems to do nothing but turn round and round, and adjust it downwards until nearly off, and then out a bit at a time using the plastic knob off of the other side of the rad temporarily. Then when all the radiators are balanced correctly they will all get hot at the same time. There is a more technical way of doing it by comparing the water temp leaving and returning back to the boiler, but by basically turning down the rads that are hot, and up the ones that are cold, will get the desired result. The other side of the radiator, which has the knob that turns can then be used to turn on and off any rads as required. Hope that this helps.