Easy freeze protection

[Zeppelinium]

All you need is a method for monitoring the temperature of your fresh water tank, or something physically close to that. If the temperature falls close to freezing, what you need to do is put a little hot water into the tank. This is actually very easy. A 12V solenoid operated water valve connected between the hot water line and a tube into the tank can do the trick. Theory of operation is a temperature controller sees the low temperature and opens the valve. When the valve opens, hot water flows into the tank from the hot water heater, the pressure drops, the pump turns on and replaces the water with cold water from the tank. This loop continues until the temperature controller sees the temperature come back up.

This is many times more efficient than having the space heater blow hot air down into the tank cavity. The heat goes directly into the water and is not blown around in the air surrounding the tank to escape to the outdoors.

This also circulates water through the cold side of your system, keeping it above freezing.

This device (http://www.banggood.com/DC-12V-50-to...-p-933303.html) available at BangGood.com for $4 (and I bet many other Chinese suppliers) is the perfect controller. You can set you desired temperature and put the sensor away from the unit, so the unit can be mounted in a convenient place (with an on/off switch so you probably only turn it on at night). A solenoid valve is about $10.

If you have a pesky pipe location (for those of you who are still using copper), you can install a second controller for that location and wire it in parallel with the first one.

Zep

[Zeppelinium]

'Tis the season. I was reminded of this yesterday by an ad for the temperature sensor, only $2.33 and 12V valves are less than $10. The image below shows in dotted lines the plumbing that is needed. Pretty simple if you have access.







Zep

[TheGreatleys]

Originally Posted by Zeppelinium

'Tis the season. I was reminded of this yesterday by an ad for the temperature sensor, only $2.33 and 12V valves are less than $10. The image below shows in dotted lines the plumbing that is needed. Pretty simple if you have access.

Attachment 324630


Attachment 324631


Zep

I did this exact thing with my fresh tank. 12 volt solenoid controlled by that same little thermostat (I bought the one with the acrylic case on Amazon) dumps hot water into my fresh tank until the setpoint is reached. I purchased a temp sensor with a longer wire and dropped it down my tank fill so it sits on the bottom of the tank.

I also added a momentary switch which allows me to prime my hot water lines without wasting any water. Turns out I use the momentary switch more often than the thermostat.

The downside for the retrofit is having access to install the return line in the fresh tank. I added the return while I had my tanks out for my shell-off renovation. I suppose you might be able add a wye into the tank fill and add the hot water that way without having to drop the tank.

[uncle_bob]

Hi

There are a lot of things on a trailer that can freeze. A full fresh water tank is much less likely to freeze than a number of other things .....

Bob

[TheGreatleys]

This is my basic setup under the sink, though it's not much to look at. You can see the thermostat at the bottom (displaying temp in C), the solenoid valve peeking out in the back, and a bank of switches on the left. The momentary switch is on top, the power to the thermostat the second one down. The bottom switch is an unrelated electric heater for the fresh water pipe from the tank (not needed if you run the thermostat controlled heat, but helpful if you accidentally allow it to freeze).

The thermostat is set up for cooling out of the box. You need to hold the left button for five seconds to get to the menu, then change the P0 setting from C to H for it to function as a heater. The manual did not come with the thermostat, but can be easily located online by searching "W1209 thermostat manual."

[uncle_bob]

Hi

The main things that freeze first are the anti-backflow / pressure regulator valve on the city water intake, the waste water valves, and the drain valves under the trailer ....

Bob

[TheGreatleys]

Originally Posted by uncle_bob

Hi

The main things that freeze first are the anti-backflow / pressure regulator valve on the city water intake, the waste water valves, and the drain valves under the trailer ....

Bob

Not sure I see your point. It's very helpful to keep my fresh water system operational in freezing weather. This system allows me to do that off-grid with very little electricity and minimal propane.

No, this approach will not keep my waste system liquid. But running water is still useful, even if I need to catch it in a dish bin to keep it out of my gray tank.

[Zeppelinium]

Originally Posted by uncle_bob

Hi

The main things that freeze first are the anti-backflow / pressure regulator valve on the city water intake, the waste water valves, and the drain valves under the trailer ....

Bob

The city water intake is a real problem, especially if you are boondocking. I handle it by removing the anti-backflow fitting and installing a manual ball valve inside (in my 73 Safari, the city water comes in under the shower/sink surround, so I can reach it) in a geometry that allows the first 18" of the pipe to drain, so there is no exposed pipe with water in it.

All my drain valves are inside, so even though they aren't in the best locations, they are generally safe.

I protect the waste valves by adding antifreeze and by limiting the amount of water in the tanks.

Zep

[OTRA15]

Originally Posted by uncle_bob

Hi

There are a lot of things on a trailer that can freeze. A full fresh water tank is much less likely to freeze than a number of other things .....

Bob

Yup!

A chain is only as strong as its weakest link.

Depending on the prevailing wind, the weakest links can be buried inside a windward wall, or under the bed.

Don’t ask how we learned this lesson!

[overlander63]

The best way to prevent freezing your trailer in cold weather is to travel in it to some place warmer.

[uncle_bob]

Originally Posted by OTRA15

Yup!

A chain is only as strong as its weakest link.

Depending on the prevailing wind, the weakest links can be buried inside a windward wall, or under the bed.

Don’t ask how we learned this lesson!

Hi

Ok ... how did you learn this lesson?

(We learned exactly the same lesson "out in the field ... )

Bob

[TheGreatleys]

All of our plumbing is custom, so I was able to build in reasonable accommodations for freezing weather. Our water inlet is valved off and blown out, and we use water from the fresh tank in freezing conditions even if a hookup is available. All of our low point drain valves are located inside the living space.

The living space itself needs to be kept above freezing, since there's lots of stuff in the living area that can be damaged by freezing, including ourselves. Off-grid, we heat the living space with our wood stove.

This system would work best for addressing cold spots if it creates a loop through your entire water system with as few dead legs as possible. Our pump is on one end, the entire cold side is before the water heater, then the entire hot side is before the return to the tank. You can put the temp probe anywhere you want, so if you have a pipe that tends to freeze first, you could put the temp probe on that pipe under some insulation. It should work provided that pipe is inside the recirc loop. If you have PEX pipe with plastic fittings, it might be worth it to add one brass fitting in contact with the temp probe for better heat transfer to the probe.

If you're able to avoid freezing weather, that's great, but we can't always. We're living full-time, not vacationing. Sometimes we have a work or family need, and sometimes the weather isn't what we thought it would be. This works for us.

[GMFL]

Don’t rely on Airstreams furnace ducting. They botched mine. Hole was there, but they only cut a small hole in the vinyl flooring.

[ROBERT CROSS]

OMG...looks like they used a hammer & screwdriver to make such a precise hole.😂
Too much trouble to go back to the tool crib and get the hole saw you forgot. 👎😡

Did you consider a diverter when full heat not needed?

That may have been the excuse for such a small opening.👎

Bob
🇺🇸