Gas tankless water heater

Navy showers are for Navy folk !!!! and not for RVers.

Your WH tank will be large enough unless you love staying in the shower for 1/2 the day......

As others have said 1 gal of hot water mixed with 3 gal of cold water will be more than enough for a shower. I timed my showers once and I'm in and out in less than 2 minutes which equates to 2 gallons of water.

In - Wet, lather, scrub, rinse - out

I bought a new TT in Dec 2014 and my first stop was to get the Truma continuous HW heater installed. I then left on a 144 day trip to Alaska and back.

There were a couple of nights where the temps got down into the mid 20's. (I left the cold water run at a trickle to prevent a frozen hose.) No problem with the Truma. You have to adjust the amount of cold water you add to the HW. I didn't have any problems. Cold water temps were probably coming in about 40 degrees.

As for propane consumption, it only uses propane when you are using HW. When not demanding HW, NO propane is being used. With the 6 or 10 gal tanks, unless you turn them off, they will monitor the temperature in the tank and turn the propane on to keep the tank at the set level.

I traveled by myself and could go two nights without a sewer connection before my gray water tank would get full. I stayed at a couple of campgrounds for 7 to 10 days. I would use the full hook-ups, open the gray water valve and leave it open. Maybe a day or two before moving on, I'd close the gray valve so I'd have something to flush the hose after dumping the black water tank.

Tankless water heaters are designed for a specific water temperature difference and flow rate. If you match that, they are fine. My experience has been variable. I've used a tankless heater in the tropics that delivered steam to the kitchen sink. I've used them in hotel bathrooms in Europe and Asia that did a fine job keeping up with showers. I have no experience with RV units but have heard complaints about fluctuating temperatures.

Even tanked heaters can be a problem. I run my gas water heater at home at a temperature where I can be comfortable with hot only for a shower, but if I run hot water long enough that the burner comes on, the water delivered gets too hot, because the thermostat is at the bottom of the tank.

For tankless, BTU inputs are usually constant, only choices are "off" and "on" and if "on" is adequate it can be too much; if not adequate, water is too cold. A heater with a tank has a reservoir of heated water at a lnown temperature, you can mix it with cold for a steady lower temperature, but as you deplete the tank,you are at the mercy of the heating system,as with tankless.

I'm not aware of any tankless heater systems targeted to the RV market that have heating rates much different than recovery rates for 6-10 gallon RV water heaters, all of which heat water to a higher temperature than I prefer, but if the volume is small, maybe that's the way it has to be.

I agree Navy showers leave something to be desired, although we resort to them quite often as we like hitting dry camping spots. I'm also not much of a fan of on demand water heaters, having spent 9 years overseas while in the military. Temperature control tends to be primarily flow control which is often inconsistent and results in a somewhat uncomfortable shower.

It sounds like you already have a new TT. How big is the hot water heater on it? Does it have both electric and gas capability? As others have mentioned, the newer quick recovery tanks can keep the hot water running quite awhile, especially if you end up using something like an oxegenics shower head, which has always been one of my first upgrades with a new rig. We just purchased a new 5er which has a 12 gallon hot water tank. We haven't used it much, but so far the wife and I have both been able to take showers as long as we wanted, without turning the water off to soap up. Just a hot refreshing normal shower. 10 or 12 gallon hot water tanks seem to be available on many rigs now.

I have to believe that they can suck a lot of propane. If you are in a park where you are semi-permanent a large tank can be set up. If you are traveling maybe not.

Depending on what the outside water temperature is I get at least 15 to 20 minutes of hot water shower in the summer and easily 10-15 minutes of hot shower in the winter doing similar math to what Gdetrailer does, and this is with a 6 gallon heater. I don't regulate that much though cause I like some decent pressure and do have an oxygenics shower head. I also added the electric heater rod kit and have both the electric on and the gas for quick recycle times. My wife wasn't going to do navy showers either. We only wait about 10 minutes between our 10 minute showers and still get a full hot shower on the third and fourth if the whole family is up for showers like after a smoky campfire.

For previous posts on this subject search this Forum for `Tankless' and read on. I wouldn't have one on an RV; possibly on a park model.

http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/28468663.cfm

I added an "on demand hot shower" unit to my TT. The above link should take you to the post. Have you considered something like this for showers? Good luck

another thought, use your onboard water tank for showers. This water will be warmer than the ground water ,due to heated tanks or heated basement. We only have a 6 gallon tank and get a pretty good shower.And I use the CG showers to save my gas.

Jcrx7 wrote:
Wife and I will be full time living in our new travel trailer, navy style showers arent an option.

Has anyone installed one of these in a travel trailer? How about a washer/ dryer?

Perhaps "full timing" isn't for you?

If one was smart, one would realize that you CAN get a pretty long, hot shower with just a 6 gallon water heater without going to the extremes of a "navy" shower.

Are you going to get a sticks and bricks pasting you to the shgower walls, no..

How it is done..

Start hot water at low pressure, once hot you add a small amount of cold to cool the water. You ONLY want enough water coming out to create a "fan" from the spray head.

When done correctly you are mixing 1/3 hot with 2/3 cold and if you set it correctly you are using less than 1/3 gallon of water per minute.

This results in THREE MINUTES for each gallon of hot water..

6 gallon hot water tank will result in giving you 18 minutes worth of hot shower..

Washer/drier, some folks have installed them but many downsides to them like using a lot of water, taking a long, long time for one load (3 hrs) and they are pretty small so you will be doing a lot of very small loads..

To me, neither tankless water heater or washer/drier is worth what they cost..