Old-Biscuit wrote:
"...as the house batteries aren't easy to get at to check the water level or add any if needed."
And you're surprised 'they' didn't check them.
I do know the manufacture requires the dealer to keep the units maintenance up until sold. I was told that by Keystone at one time as I had a wheel bearing failure. So I would expect that it's maintenance should be kept up in order to validate the warranty.
Am I surprised they didn't check it or maintain it? Not one bit. And if I end up with a dead cell due to the water level being too low, I would certainly get the blame for not keeping it topped off.