On Board Hot Water Install for Shower

[unwiredadventures]

On past trips that lasted more than a few days, I would bring a Colman hot water heater for showers. This worked great but it took up precious cargo space and was clumsy to operate while taking a shower.

I know of two models that use use the hot engine coolant to heat water (heat exchanger). Helton and Twine. I chose the Helton Hot Water Kit because the all the hose inputs and outputs are on the same side.

The goal was to have a shower where the water heater, water pump and water were all on board the vehicle. I wanted to use the system without opening the hood.


The hardest part of the install was finding a place for mounting the heat exchanger in the engine compartment that allowed convenient connection to the existing heater hoses. I finally found a great spot under the relocated window washer bottle (relocated with Slee Kit). The heat exchanger is the red device. Bolted to the inner fender:


Heater hoses and fresh water hoses routed. Connected directly to the heater valve, the flow of the coolant can be adjusted from the heater controls on the dashboard. I found about 3/4 into the red on the heater control was perfect:


The water containers are in the rear of the truck so the electric fresh water pump (Jabsco Variable Speed Water Pump) mounted under shelf in rear cargo area:


The first flow of hot water can be scalding since it's been sitting in the exchanger so I included a cold / hot water mixer anti-scald device. This also allows more control of the warm water temperature. This is plumbed like at your home, both hot and cold water flows to the valve and can be adjusted. In addition, a valve at the top to control the flow. Opened about 1/4 of the way allowed for a good shower while reducing the water usage:


Here is the system last month, setup in Arizona next to Canyon de Chelley:


The input hose to the electric water pump in one of the 5 gallon water containers:


This system makes it very easy to take a shower. Just drive into camp. Put input tube into fresh water. Setup shower tent (with AstroTurf for the floor). Connect shower hose. Run engine at 1000 RPM. Enjoy hot shower

I ordered many of the plumbing parts from West Marine. Some of the needed parts:

3 Barbed Hose Reducer, 3/8" to 1/2" Part: SEAFIT 139952 - Helton uses 3/8" connectors. Needed to adapt to 1/2"
1 Barbed Nylon Hose Tee, 1/2" Part: SEAFIT 139960 - To allow cold water to mixer
Series 162 PVC Tubing, 3/8"ID Part: SHIELDS RUBBER 116-162-0386 - Water To / From Helton heat exchanger
Series 162 PVC Tubing, 1/2"ID Part: SHIELDS RUBBER 116-162-0126 - All water line to / from electric water pump
Brass Male Pipe Thread to Hose NPT 1/2 - For mixer, anti scald device connection to tubing
Brass Female Pipe Thread to Hose NPT 1/2 - For mixer, anti scald device connection to tubing

A few issues:
1. I need to add a valve to completely drain the system. If water freezes in the heat exchanger, it could cause it to crack and create a leak in the engine cooling system.
2. The tubing that was attached to the shower sprayer was not strong enough to withstand the pressure from the electric water pump. I replaced it with 3/8" tubing from West Marine.
3. The standard hose clamps on the fresh water system under the hood, appear to loosen with the cycle of heating then cooling which causes very small leaks. Re-tightening fixes it, but I need a permanent solution.
4. I need some type of quick connect for the shower hose to the truck.
5. Need to install manual throttle.

 

[lcsodiver]

You my friend are brilliant!! :wings: The only reason I don't like using my shower without a unlimited water source... (creek, lake, water spigot) is due to not being able to shut off the water without having the scalding issue when you turn it back on... I am going to incorporate this into my build.

On mine I just let the truck sit at idle, it seams to keep up just fine... you might try it, you may not need a hand throttle (though for winching it would be nice).

Also, what are you using for your shower head? the kitchen sprayer type nozzle? I just modified a brass end cap for a garden hose and use that with a hose valve... also mounting brass garden hose quick disconnects on the front bumper. (extra set of male disconnects with caps keeps things clean when not in use)

Many thanks!! :victory: Bob

 

[cruiseroutfit]

Excellent install

Regarding draining the water to prevent issues with freezing. That was an initial concern of mine as well, after discussing it with the manufacture I left it out of my system. Fast forward 5 years and now hundreds of installs, I'm yet to hear of an issue. Now, the majority of my installs are using the stock Helton components with the addition of heavy duty fresh water feed lines utilizing quick disconnect fittings that when disconnected are not pressure tight. Therefore there isn't a 'pressure vessel" existing for frozen water to cause damage. The Helton heat exchanger in my FJ40 is mounted fitting up, thus it surely has water in it constantly, we see plenty of days well below freezing here in Utah and again it has not been an issue. I will sometimes blow the water out just to prevent some nasty stagnant water from hanging out.

The immediate burst of hot water is something users should be comfortable with, your setup is the perfect solution. Alternatively particularly when I have a lot of people shower, we will just pre-heat 5 or 10 gallons of water, toss the shower head right back into the pickup water and let it cycle until it is at a comfortable level. Then, shut the motor down and shower away. We did this on the recent Carbon Neutral Expedition, figured it was more carbon neutral to hurry and heat the water rather then idle the motor for half an hour while everyone showered

Again, great install!

 

[unwiredadventures]

Excellent install

Regarding draining the water to prevent issues with freezing. Fast forward 5 years and now hundreds of installs, I'm yet to hear of an issue. Now, the majority of my installs are using the stock Helton components with the addition of heavy duty fresh water feed lines utilizing quick disconnect fittings that when disconnected are not pressure tight. Therefore there isn't a 'pressure vessel" existing for frozen water to cause damage. The Helton heat exchanger in my FJ40 is mounted fitting up, thus it surely has water in it constantly, we see plenty of days well below freezing here in Utah and again it has not been an issue. I will sometimes blow the water out just to prevent some nasty stagnant water from hanging out.

Kurt, thanks for your comments. The Helton unit has worked perfectly.

Thanks for the info about freezing.

Which quick disconnect fittings did you use?

 

[cruiseroutfit]

Kurt, thanks for your comments. The Helton unit has worked perfectly.

Thanks for the info about freezing.

Which quick disconnect fittings did you use?

Wish I could be more specific but they are just some hi-quality water quick disconnects (used on pressure washers) that I source from a local industrial hose supply outfit. They crimp on the fittings on the red hose as well.



I don't always utilize the fittings, here we used the regular push fittings on a BJ74 install:

 

[dustboy]

Nifty project, I suppose with a strainer you could drop the intake into a nearby lake or creek for longer showers!

 

[lcsodiver]

Nifty project, I suppose with a strainer you could drop the intake into a nearby lake or creek for longer showers!

Yep thats what I do :bike_rider: here is what I use for a prestrainer.....
Sprinkler

and here is the quick disconnects that I use.....

Quick Disconnect

 

[cruiseroutfit]

Nifty project, I suppose with a strainer you could drop the intake into a nearby lake or creek for longer showers!

Very true, fwiw the shower pump setup that is generally included with the Helton has a strainer/filter on the pickup unit so it can be used in reasonably clean water. I've enjoyed looooong showers by the side of a lake before .

 

[LandCruiserPhil]

<SNIP>
The first flow of hot water can be scalding since it's been sitting in the exchanger so I included a cold / hot water mixer anti-scald device. This also allows more control of the warm water temperature. This is plumbed like at your home, both hot and cold water flows to the valve and can be adjusted. In addition, a valve at the top to control the flow. Opened about 1/4 of the way allowed for a good shower while reducing the water usage:.<SNIP>

The Danfoss Thermostatic Mixing Valve 065B8867 looks to be a great find.
I'm somewhat confused is the output temp stable with a range of input temps. Looking at the PDF it shows a table with the valve have 1-6 adjustment for output temp based on the input temp?

I have never been able to shut my water flow off for more then a couple seconds with a scalding issue forcing us to look for a lake or a stream for a endless water supply. This valve will make showering with 5 gal a possibility.

 

[dbolton]

Great install - I bought one of these from Kurt a while back; while it works good, there are some definite improvements here .

One question on the pump you're using; the link you provided says that it increases speed as demand increases (being a variable speed pump). When you partially close the downstream valve, does the pump interpret this as increased head and increase speed to try to overcome it? Or does it increase speed when discharge pressure drops (signaling increased demand)?

Thanks! -Dan

 

[unwiredadventures]

One question on the pump you're using; the link you provided says that it increases speed as demand increases (being a variable speed pump). When you partially close the downstream valve, does the pump interpret this as increased head and increase speed to try to overcome it?

No, it slows down. All it does is maintain pressure.

Or does it increase speed when discharge pressure drops (signaling increased demand)?

Yes, it just keeps the pressure up to I think 35psi. If the downstream valve is shut off, then the pump completely stops. Open the valve just a little, and the pump runs slowly. Open it all the way and the pump runs much faster. It's completely variable.

The pump is designed for boats to be powered constantly with the water input always in a water tank. It only goes on when needed. If you had a fresh water tank on your truck, you could leave the pump on all the time. It would run only when you are using the water system.

The pressure is almost too much. So the downstream valve is needed to control flow for conservation. If it were 20psi it would probably be better but I couldn't find one before the trip. The pressure of this was too much for the tubing that came with the Helton shower head. Swapping the included shower head to the stronger tubing was easy. With an "unlimited" water source, you'd have a wonderful high pressure shower

When I take a shower and soap up, I switch the shower head to the lowest setting to save water. The pump slows down. When I'm ready to rinse off, open the flow on the shower head and the pump keeps up. The variable pump is key to make this almost foolproof. No need for an electrical switch for the user of the shower. This was my biggest issue with using the Colman water heater, I had to reach out the tent to turn it off when soaping up, then back on when rinsing. I believe that the Zodi (and other similar) can be damaged if run dry and have the issue of scalding water at first. This system can run dry and the ant-scald prevents scalding water.

The idea was to make it like home. No special instructions needed for the person taking a shower. This saves water. I found between 3-4 gallons to be an almost perfect shower.

I'm also planning an output for the rear of the truck for fresh water. As long as the input hose is in a water source, the pump can be powered on.

 

[unwiredadventures]

The Danfoss Thermostatic Mixing Valve 065B8867 looks to be a great find.
I'm somewhat confused is the output temp stable with a range of input temps.
Looking at the PDF it shows a table with the valve have 1-6 adjustment for output temp based on the input temp?

Unfortunately this project was completed just a day or two before a 10 day trip. In camp, I set the dashboard interior heater control to between 1/2 to
3/4 towards the red I didn't have much time to test it much in advance. It worked perfectly in camp. I believe I had the mixer / anti-scald set to the coldest setting? I'll do some testing tomorrow.

I have never been able to shut my water flow off for more then a couple seconds with a scalding issue forcing us to look for a lake or a stream for a endless water supply. This valve will make showering with 5 gal a possibility.

When I first hooked it up, without the anti-scald, I tested by stopping the water flow and turning it back on. Wow, the water was so scalding hot each time!

With the mixer anti-scald, it is a little bit hotter to start but not even close to scalding.

 

[JackW]

My setup - I used a flat plate style heat exchanger I sourced off Ebay for around $75, a Shurflo 2 gpm pump, a mixing shower head and various quick disconnect fittings and hose from Mcmaster-Carr, and a Pelican case I had lying around.

I figured I'd put the pump and plumbing distribution in the Pelican case where it would be out of the reach of mud and vibration and I wanted to be able to mix some cold water since the flat plate exchangers are VERY efficient.

Pictures are in this thread:

http://expeditionportal.com/forum/showthread.php?t=28275

 

[AZUnlimited]

Very interesting thread. Thanks for detailing this out. Looks great!

 

[Uticon]

Does it matter which heater hose you connect the heat exchanger to?
T'stat side or water pump side?
Thanks:victory: