my winterization though the city water inlet and a pump and bucket with the pink antifreeze. They did not work from the manifold that controls the access to the three water tanks as I normally do, by the traditional method of pumping dry, disconnecting and then running a line to a bucket and having the water pump push the antifreeze through the system. They drained the tanks and did the pink insertion from the outside city water inlet never disconnecting anything at the fresh water pump inside, and with all the taps and shower head open until it ran red.
No problem this spring.