Sometimes I'm asked if it's really that important to winterize your pressure washer. The answer depends on where you live and how you store your pressure washer. Basically, if your pressure washer is going to be exposed to freezing temperatures, you need to winterize it. If you don't, you may find that the engine starts up fine the following year, but your pump may not function. The water that remains in the pump freezes, damaging delicate pump components and eventually renders the pump useless. New pumps cost at least $100, so it's worth taking the time to winterize them.