Water Heater Tank Empty

[jlawley]

I've been winterizing trailers for over 30 years and this has never happened before and I'm really stumped. Last night I opened the low water drain valves and the freshwater tank drain valve. Today I come out and nothing is dripping anymore. I go into the trailer and reverse all the valves (water heater bypass valves). I then proceed to pump antifreeze into the kitchen faucet, the bathroom faucet, the shower, and the toilet. Everything went as it always had. Then I realized that I had forgotten to drain the hot water tank. So I went outside and removed the plug. Nothing came out. Not one drop. Thinking it might be some sort of vacuum thing I put all the valves back into summer configuration. Nothing. What could have happened to all that water? We took showers the last camping trip 2 weeks ago and everything was working great. Even if I can't figure where the water went, can I be sure that there is no water in there that might freeze this winter? I'm confused. Thanks for any help you can give.

[bankr63]

Your hot water tank will mostly drain through the low point drain given enough time, that should be what happened here based on what you said. Some water may be left if the water outlet is higher than the plug, although a little bit of water left in the tank won't harm it from freeze expansion - it has lots of room to expand. If you want to be extra sure it's not held by vacuum, just pop the pressure relief valve to let air into the top of the tank.

I suspect in the past you may have done the bypass before the drain, thus why you were expecting to find water still in the HWT?

Note that if you moved your valves to the summer position with pink stuff in the pipes, some will now be in your HWT as well. Be sure to flush it before using again next season.

[jlawley]

Thanks Bankr, I was hoping it was something like that. I just can't believe there wasn't one drop left in the tank. The plug came out dry. I'll have to remember to do it in the order I usually do it next year: drain the HW tank, drain the FW tank and open the low point valves, change the valves to winter setting, then pump the antifreeze through the lines. All that makes sense. This caught me by surprise. Thanks again.