Winterized Our Lance TT Today

It is usually a good idea to turn off the water pump and relieve MOST of the pressure on the water system before depressing the back flow preventer valve at the water inlet. Depressing this button with full pressure on the system very often results in blowing the O ring off of it's seat which will cause the water to blow out this valve next year when you pressurize the system. SOMETIMES you can maneuver the O ring back into place and this will work temporarily but often it is necessary to replace the check valve for a permanent fix.
Good luck / Skip