I blow mine out every year. I screw the air chuck/water line into the water inlet, hook the compressor to the input, set it to 50PSI and open the faucets until they quit spitting. I then go over the whole process a second time. Make sure there is no water left in the pump. I also do not use the water heater bypass but drain the water heater and put the plug back in to blow out. Add a little pink stuff to the drain traps and let it freeze. When I am ready to go in the Spring I don't have to flush the pink stuff. The whole process takes about 20 minutes and I get 2 years out of a gal. of pink stuff.