Hi Andy, No that's not normal, i assume you have a on-board pump, the most common reason for this is air in the pipework, it's critical to make sure all the air is out of the system and there is no restriction in the supply from the aquaroll to the pump.your dealer should be able to sort this for you, when i picked up my new Abbey i had a similar problem very noisy pump, made sure the system was primed properly, there was a kink in the supply pipe, adjusted the pressure switch and problem sorted, the pump is now as quite as the submersible in the old van.