How to keep jerry cans from freezing when boondocking?

Back on my topic of keeping the jerry cans from freezing, I just measured the area next to my toilet, and we can indeed keep one can inside. We would take it out for showering (we have a wet bath), but it would not be in the way most of the time. So I think that when camping in really cold weather, we will do this as a backup, in case our water lines freeze.

Would be nice to have a box of these and extra duct tape on hand in the event they are needed:

6 Patches Of Hand Warmer Heating Pad-4 Minutes Heat up for 14 Hours

Just not sure if there is easy access to the exterior pipe from your pump that goes into the fresh tank.

I also wonder if one of these pads taped to your outside covered jerry can would be enough to keep it from freezing. At least the pads do not require a powered source for heat.


There is also this very small DC powered heating "pad" (10cm X 5cm) that can draw less than 1 Amp. That might be low enough to run on your existing power. Towards the bottom of the item page there is a link for spec sheet where the power information is available.

Electric Heating Pad - 10cm x 5cm

Steve, I looked at the schematic, and it is beyond my pay grade -- a brilliant solution. But it gave me an idea for a simple manual work-around, and I have posted that proposal over on the Do It Yourself forum (since we have now gotten far beyond my frozen jerry cans).

Thanks again for your creativity!

Here is a link to the discussion of the manual work-around

Thanks Mike.

Pictures would do very little good because everything is covered in foam pipe insulation. I have sent you a schematic though.
The system can operate in two modes, timer and thermostat. When the sensor detects that the galley sink hot water supply is below 85 degrees, the valve opens (allows water to flow). The sensor is mounted to short length of copper pipe so good insulation is critical.
Yes, when the pump cycles, there is noise. I have tried to dampen it as much as possible, but it's still there....and I don't like it when sleeping. Hence my move to the radiant heater that also warms the floor (and tank) and, as a bonus, me too.

Smkettner did something sort of similar, but used a solar pump instead.

If I was to do it all over again (and I would for water savings and instant hot water), I would probably just buy a little 30 second timer off eBay instead of building one and I would also eliminate the temperature sensor. KISS

Wow! Steve, great idea! Now for the inevitable questions. First, would you consider taking photos of the project and posting them on the DIY forum, perhaps with some explanation of the circuitry? Second, does this system cycle on and off during the night, and does it make a lot of noise? I would put up with a little noise, in return for keeping the outlet pipe from freezing. Thanks in advance -- this device could make a big difference for everyone who likes cold weather camping (and don't we all?). ;)

SteveAE, i really like that idea. Using the relatively small amount of water, recirculating back to the tank (or pump input) due to the pressure difference when the solenoid valve is opened is a great idea. The pressure tank allows more of the water to move before the pump turns on. Then, if the pressure never reaches the pump shutoff value, it just recirculates. A timer would be helpful here.
Nice mod.
Mike

profdant139 wrote:
tpi, if you can figure out how to do that, I am very interested!! Not sure how the plumbing would run to and from the fresh tank and the hot tank.

Simple.

In my trailer, the galley sink is above the water pump. It is also the last fixture in line for hot water but that is not important for your application. I also have a small pressure tank (folks here call them accumulators) on the water line which helps what I did below work even better.
I Teed a solenoid valve into the hot water line under the galley sink and ran the outlet down to the water line between the freshwater tank and the pump (could have also ran it into the water tank vent line if I didn't have the pressure tank). Valve opens, and water runs back into the tank. Then the pump turns on and brings that water right back into the water system. In my case, the valve is controlled by a temperature monitoring and timer circuit, but you could easily just occasionally turn it on and off via a pushbutton switch.

A handy mod for reducing freeze potential, providing instant hot water, and for saving water.

As one poster said if you could get the fresh tank enclosed and then put a 12 volt fan blowing warm cabin air in with a return vent into the cabin would be ideal. JMHO

Thats a interesting idea, all though you could get some rotten egg smell in your fresh water tank if it sits to long.

tpi, if you can figure out how to do that, I am very interested!! Not sure how the plumbing would run to and from the fresh tank and the hot tank.