You can remove snow using a power washer as long as you are mindful of cold weather conditions. Winterizing your power washer, as well as yourself, is critically important to maintain the health of your machine and keep from getting hypothermia by spraying water in freezing conditions. This method is not for everyone, but the power washer enthusiast can make it happen.
Prepping the Power Washer
Storing your power washer in a warm place is important. Any water left in its system can freeze and expand, cracking the reservoir or hoses. If your washer is gas-powered, use a fuel stabilizer to protect it from getting water in the gas due to condensation. This can be purchased at a hardware store or auto parts store. If your power washer has a tank, flush the whole system with RV antifreeze. Do not use car antifreeze, as that is different. RV antifreeze is much safer for the environment.
Personal protection is extremely important when using a power washer in cold weather. Dress warmly and then cover with a layer of rain gear. Wear waterproof boots. You can even put a large pair of socks over your boots to prevent slipping on any ice that may form.
If your power washer hooks up to a garden hose, make sure the hose is not frozen. If so, it will crack and leak. Hook the hose up to a hot water source in the garage, or even the hot water intake for the washing machine should fit your standard hose. Just remember to hook the washing machine back up when you are done. A kitchen sink faucet may also allow your hose to connect after unscrewing the cap that holds the screen. As soon as you finish, empty the hose of water and put away for storage.
Most deicers available are made with salt in one form or another, or even a blend. You can also use a window washer fluid which has a lower freezing temperature because it is alcohol based. This type of product is better for your driveway and will evaporate faster than water. The surface will still be wet when you are finished, so sprinkle sand, kitty litter or rock salt on it to prevent an ice rink. Here is a link to an article from Consumer Reports explaining how deicers work.
Timing and Technique
Using a power washer outdoors in the cold should only be done during the warmest part of the day. This is usually between 11:00 a.m. and 3:00 p.m., preferably when the sun is actually shining on the driveway. If the snow is deeper than 8 inches, it is a good idea to shovel at least some of it off first. Often there is a stubborn layer of ice below the snow, and the power washer will take care of that. Once you start the spray, don’t stop. Keeping the water moving through the hoses is important to prevent freezing up. Sweep the hose back and forth constantly over the snow you wish to remove. You may have to work in layers, depending on the depth of the snow. Use a nozzle with a fairly wide angle and adjust the pressure up as needed. Smaller nozzles may just carve tunnels in the snow. Once the top layer of snow is blasted away, aim the spray horizontally to try and lift that bottom layer of ice off the driveway.
How Cold is Too Cold?
It is best to do a job like this on a calm day when the temperature is at least 20 degrees Fahrenheit. Obviously, the closer it is to being above freezing the better this will work and the less chance of damaging your equipment and health. Wind can make the cold even colder, so take wind chill into consideration. If there is more than a light breeze, consider waiting until another time. If you have direct sun on your driveway for part of the day, you can get out there when the temp is a little colder.
Before storing your power washer, empty all water from washer and hoses. Store the power washer in a warm place if possible, such as an attached garage or basement. A garden shed will not be warm enough to prevent freezing. A water heater gives off some residual heat, so store next to that if it is in your garage. If you must store in a freezing cold place, siphon RV antifreeze through the reservoir and hoses. Any water left in the machine will expand when frozen, and it can break or crack small parts. Here is a helpful video of how to properly winterize a power washer.