It is not very loud at all. If you have it hooked up correctly you have to bleed the line. So unhook it from the nozzle on the cage and then press the up arrow and then hold it on the timer. This will kick it on. It will push all the air out of the line and you will get water coming out the hose. Then you need to reattach and push the up arrow and hold again to get the rest of the air out.