Next year I'll winterize in September

[BombardierBratz]

My timing didn't work out so good this year. With work picking up, my days off schedule and the +33 degree weather we had only two - three weeks ago, my fifthwheel didn't get winterized. It hasn't been any colder than -10 but that was cold enough to freeze my system. I pulled it into the shop where I work to gently thaw it out, but found that my water filter had split. I thawed the tanks & the hot water tank alright, the pump itself looks fine, but there is a low pressure screen filter just prior to the pump suction that is cracked. There is evidence of a previous repair done on it. I usually take it in to have it winterized, but I couldn't get an appointment untill Oct 16th. Whomever had the system apart last, might have wrecked the threads on the screen filter and we found silicone on the inside of the threads of the unit. With the unit freezing, the threads are now really shot and I can't seal it to continue to purge the water lines with antifreeze. I drained everything, and will keep my appointment to have it winterized, but they will have to repair it first. I enjoy learning new things, but it seems I get these new lessons after I screw stuff up, lol! I pulled the plug on the hot water tank, thawed it and decided to leave the plug out.
I read online and refered to my manual, and I noticed that most refer to a three valve set-up on the hot water tank. Mine has two valves. One valve stops the fluid flow to the hot water tank at the bottom (I assume thats the inlet) and the other valve is the bypass to the hot water lines for purging / filling with antifreeze. What seems to be missing is the valve that inhibits the backflow of fluid into the top (outlett) of the hot water tank itself. Without this valve, antifreeze would gravity feed backwards into the holding chamber of the hotwater tank, then simply flow out, as I have removed the plug.
My question is this: Is it ok to have antifreeze in the hotwater holding tank (obvious poisoning situation), and should I have a third valve installed so I can completely isolate the hot water tank for winterization? My tank is round, and the plug and fresh water inlet are at (think of a clock face) the 5 and 7 hour positions, leaving about two liters of fluid in the bottom of the tank at all times. I really hope the rest of the system is ok.....

[Stompin Tom]

I have always drained my hotwater tank, then isolated it with the 3 valves leading in and out of the tank. I have done this for years and never had a problem.

The problem with putting anti-freeze in the tank is cleaning it the next spring, alot of flushing.

[medler]

The antifreze won't hurt the tank,it just will take a while to get it all out.And it should have 3 valves in the hot water tank area..Can you blow the rest of the lines out with an air hose?Don't forget outside shower.

[RMK Junky]

There is such a thing as non toxic antifreeze. Use it all the time throught the whole system. Doesn't take much to flush out in the spring and no funny taste. Good to -50 with the Polar from Canadian Tire. 8L to do the whole trailer.

[Zar]

I blow out the line with a air compressor ( regulated down to 30 psi ) to get the majority or the water. Then I fill the lines with anit freeze (via the fresh water holding tank bypass - another 3 way valve prior to the pump inlet). Using air takes less anti freeze and in the spring use compressed air again to get the anitfreeze out. It will take less fresh water flushing to get the antifreeze out. Also most trailers have two drain plugs on the lines that are underneath the trailer on the outside ( you have to crawl under the trailer to find them ) - these help get most of the water out. I pull the plugs on the hot water tank after the Sept Labour weekend just to be sure. I avoid filling the fresh water holding tank with antifreeze - it take forever to get the trace of antifreeze out.

[higher n you]

The reason you have only 2 bypass valves is the top of the tank has a one way check valve installed so that hot water may leave and cold water will not return. Throw the water filted out and winterize directly from the pump.

[Scuba]

I also will be winterizing earlier as my trailer has some defrosting to do hopefully the warm up this weekend will help me out, tried to thaw the lines got about half way done then stopped before i started it on fire. First time in 50 years that it has been this cold this early. I sure hope that it warms up.

[BombardierBratz]

I hope this global warming doesn't get out of controll....lol

[teeroy]

Originally Posted by RMK Junky

There is such a thing as non toxic antifreeze. Use it all the time throught the whole system. Doesn't take much to flush out in the spring and no funny taste. Good to -50 with the Polar from Canadian Tire. 8L to do the whole trailer.

same stuff I've been using, I can fill the lines (bypassing the water heater) with 4L, and use one other 4L jug for the p-traps.

BombardierBratz: almost had a Julio with my trailer too, couldn't get to it right away when it got cold out so I just fired up the furnace and figured it would be okay until I could get to it.....shoulda checked to see how much propane was left first....don't know when it ran out but when I got to it she was frozen. Only saving grace was that I had pulled the hot water tank plug when I lit the furnace. everything pressured up okay when I winterized it tho....thank heavens.