When we bought the trailer its old hot water heater had turned up its toes and died. No more hotsies from that old thing. So we spent $675.00 having a dandy new six-gallon hot water tank installed. We failed to get the manual and because we have a real talent for missing the obvious, we misunderstood the 10 second "Introduction to your new water heater" lecture.
Okay, he said you have to light it from the outside when you want hot water. I will swear that he said you have to go outside and turn the &^%(*% thing off when you are finished using the hot water. Tony remembered this way as well. This seemed like an awful lot of fol-de-rol for a pan of hot water, so we have never even turned the darn thing on, other than once, to make sure it works! I've just been using the kettle and heating the small amount of hot water we need to do dishes, Tony's shaving etc.
I'll admit washing your hands in freezing temp water is not all that comfy, but man evolved a long way before he invented water heaters, so we knew we'd survive. Back in our youth many apartments were what were called "cold-water flats", i.e. there was running water, but no hot water. So, we were back in a cold-water flat, just on wheels.
But we have been worrying. Like this. "The water heater has water in it. It is getting very cold. Cold makes water freeze. Freezing water expands and will burst a closed container. How do we keep our new water heater from freezing and popping it's expensive rivets? How do we drain the water heater?" We could find no way, other than draining the entire water system for the winter, and I really don't want to carry water all winter.
Well, a few days ago the RV service guy, Gary, and another park resident, Jim, came and put the winter skirting on the trailer. The next day we asked Jim about draining the heater and he looked at it, in a puzzled sort of way, before saying he'd ask Gary to have a look when he was back next time.
I'm almost embarrassed to say it. Gary came this afternoon, took me out to the water heater panel, lit the thing and explained that you don't drain it to protect it from freezing. (He didn't say "You don't drain it to protect it from freezing dummy..." for which I am profoundly grateful.) He said, "You light it! The pilot light kicks the gas on whenever the water temp drops and you have 1) hot water to wash your face and 2) protection from frost."
Once he said it - Oh geez, what could have been more obvious?
The nice thing is - I now have hot water to wash my hands in. What a luxury. Thank you inventor of hot water heaters, and thank you Gary, for not laughing, when you must have wanted to REALLY REALLY badly. I can explain how cell membranes regulate electrolytes and and neuromuscular junctions change electrical signals to chemical ones and then reconvert them back to electricity, just don't ask me about pilot lights.