Answer to my own problem...the anti-siphon valve on the city water input. It's made of 3 parts (a spring, a plunger and a keeper). I guess during the freezing weather the input froze and caused the keeper to separate from the plunger. This allowed the plunger, under pressure, to seal on the inside connection thus preventing water from getting in. I put faucet covers on all the outside faucets but did think about the input fitting for the TT.
But the true travelers are they who leave for leaving’s sake
Saying continuously, without knowing why: ‘Let us go on’.
Paraphrased from Baudelaire’s ‘The Journey’
Joe and Penny
Mischief and Spanky (Shih Tzus)
2013 Crossroads Z-1 29' Travel Trailer