Thanks for replying to my note. My house has no basement. It's one story, constructed on a now-crumbling cement slab. There's a valve on the water heater that would do nicely, but it's somewhat above the tank, which is somewhat elevated, and at the back ot the small closet enclosing the heater, and since I no longer stand on ladders or other furniture, it's out of reach. I'm experiencing leg weakness and loss of balance, so everything needs to be between ankle-high and six or seven feet above the floor. My suggestion for those building or otherwise acquiring houses where they expect to spend their declining years is to avoid features requiring you to reach the ceiling or the floor. This is especially true for individual folks living alone.