How can I build a freeze proofed water system for my trailer?

[WilloCo]

I've got a M716 that I'm going to build into a camping trailer. I'd like to use it during elk/deer hunting season in Colorado - which means freezing temps in the mountains.

One Turtleback trailer review mentioned that the water heater could be used to keep the trailers water from freezing.
Has anyone documented a build for this? I haven't found one yet and I'd really like to.

If I don't find an example to work with, then I suppose I'll just have to build it.
I'm thinking of something like:

• a 30-45 gallon tank. Yes that's alot of water but I almost always have to put out some idiots unattended camp fire.
• extra water return line that could circulate heated water back into the main tank.
• Tankless propane water heater - need to do some research here
• Insulated cabinet with the water lines, pump - Rigid foam on all sides
• Custom h2o thermostat to control water temp - and probably to circulate water through the pipes to prevent freezups.
• Bonus: Air blow out valve to remove water from exposed lines for extreme cold/travel (think kitchen faucet)
• Tank heating pad for shore power/towing - Like https://www.etrailer.com/RV-Fresh-Water/LaSalle-Bristol/277-000164.html

Did I miss anything?

 

[WilloCo]

Very good point, I am probably overthinking things but it's much harder to add features later on.

 

[billiebob]

Keep everything compact.
Water flows downhill so have a drain at the bottom, valve at the top, one line. No horizontal runs.
Open both valves, let gravity bleed the system. Do that everytime you move/drive.

Otherwise, unless you are incredibly anal, eventually you'll freeze something.
And forget the on demand hot water, boil a pot on the stove.

Do you need that fire fighting water in the winter?

 

[WilloCo]

Sadly, yes. I live at 9000ft and it's usually snowing for rifle season. Archery season is usually still a little mild.
2 seasons ago, I came upon an unattended camp fire with 4 foot flames - these geniuses apparently put ALL their wood on the fire and then left.
It took me 2 hours to get it fully out between random water bottles in my car and tearing the fire down.

I've found smoldering camp fires on various occasions. My old neighborhood almost burned two years ago thanks to idiots with a camp fire.
I'll happily drag around an extra 400lbs of water in case I need it.

I suspect I only need to add some heat to the water supply now and then to keep it freezing if I insulate enough - I like your idea of gravity clearing the pipes.

 

[Teardropper]

Tank heating pad for shore power/towing - Like https://www.etrailer.com/RV-Fresh-Water/LaSalle-Bristol/277-000164.html

That thing sucks 4.8 amps/hour. That's 115 amps per day. Not realistic unless you have another trailer to haul your battery bank in.

T

 

[dreadlocks]

Beware, many LP tankless water heaters have altitude ceilings much much lower than 9k ft..

how long are these hunting trips? do you need to keep 30 gallons from freezing in 3 days? easy, just insulate it.. a couple weeks? eh, yeah probably gonna need some sort of heatsource every once and a while..

Could water tank stay internal to sleeping compartment? if you isolate it from the trailer body and insulate the bottom, then make a bed ontop and put a propex next to water tank with inlet on one side and outlet on other side it would circulate heated cabin air around the tank and keep it from freezing, and also keeping you warm.. in a small trailer, LP and Electricity usage would be negligible really.. or something like a Wave heater which takes zero electricity and would do a fine job just few feet away from an exposed portion of the tank.

 

[Teardropper]

That heater mentioned uses a thermostat. Unless its so cold it never shuts off, daily Ah consumed will be less than the 115Ah mentioned.

I'm sure your right but the info says that it turns on at 45º and shuts off at 65º. Heating that water 20º with 4.8 amps is going to take a long time. Using DC current for heat is a nasty drain on batteries.

Your best bet is to insulate the heck out of it and let its mass hold the heat. You may have to add a coffee pot of boiling water from time to time. Add a thermometer.

T

 

[WilloCo]

That thing sucks 4.8 amps/hour. That's 115 amps per day. Not realistic unless you have another trailer to haul your battery bank in.

T

I agree on power usage, but I don't intend to use that with the battery.

Key point here is that it would be used with *shore* power/towing, I'm referring to running it when the trailer is plugged into 110v at home/campsite or when connected to my running vehicle where the power usage won't matter. The idea being if it's freezing outsize I can fill my water tank and keep it warm a few days before the trip and not worry about it.

For camping - say several days away from power, I figure I'd use the propane water heater to cycle some heated water once in a while.

 

[luthj]

There are freeze tolerant plastic lines and fittings. Combine those with tanks that can be drained. A fitting to blow some air through the system may have value.

 

[WilloCo]

Yeah, PEX is pretty much the way to go as far as I've seen.

 

[Alloy]

We use our trailer on trips through the winter so the water system had to be frostproof and easy (no antifreeze) to winterize.

For hot/cold outside water I installed a Woodford frost free faucet.

Woodford Model 22 Hot and Cold Freezeless Faucet

www.woodfordmfg.com

All the lines are Uponor PEX. Fittings are ProPex plastic.

Residental Solutions | Uponor

Learn why PEX piping from Uponor is the superior alternative compared to rigid copper and CPVC. For residential plumbing solutions, more builders choose Uponor PEX pipe.

www.uponor-usa.com

Lines are sloped towards the low point drains and there is an air connection.

Tanks have 2" Formula 250 XPS (extruded polystyrene) on bottom and 3/4 of the way up the sides. At one end the XPS is slotted to allow air from heating ducts that can be opened.

FOAMULAR® 250 -

www.insulation.supply

The hardest part was the low point drains that come out of the bottom of the tank. Tried both gate and knife valves but these were to big. Ended up making 3/4" x 6" pipe plugs from polyethylene rod. The plugs also hold 2" XPS that insulates the openings.