Tankless Hot Water

I switched to a tank-less several years ago. These are great if:
1. You are connected to full hookups
2. If traveling you can fill up the fresh water tank every few days and dump the grey.

Outside of that, if in my future I see traveling for fun and not work I will make sure that I have at least a 10 gallon multi-fuel heater.

I do like mine but it will limit you on where you can go and for how long.

Bumpyroad wrote:

if truma is so great, why do you need to do this?
bumpy

As with any type of system, there is always the lag time from the location of the water heater to the farthest tap location. This type of point-located heater is used to avoid running the water until the hot water "gets there".

As I have iterated in the past, we do not "camp". For us this is a functional equivalent of a hotel suite, in mobile form. As often as possible we try to emulate all of the comforts and technology that we enjoy in our home.

kedanie wrote:
Any tankless system can only raise the water temperature by a certain amount, so if the incoming water is real cold then the max temperature output will suffer some.



Keith

Keith, if you are obtaining less than optimum temperature control I would encourage you to examine the Truma system. We have not had that experience with ours. We have had consistent 120f water temperature even with 38f incoming.

The Truma uses microprocessor-controlled stepless burner management that adjusts the heat output from 20,000 to 60,000 BTU based upon incoming temperature and flow rates.

We had our tankless replaced with other cause we hated that thing :)
Would not do another in the rv.
Scared to death it would burn up the kid in the shower. (and other issues with it)

best of luck if you get one!! Hope it works out fine for you!

Planning wrote:

kedanie wrote:
Any tankless system can only raise the water temperature by a certain amount, so if the incoming water is real cold then the max temperature output will suffer some.



Keith

Keith, if you are obtaining less than optimum temperature control I would encourage you to examine the Truma system. We have not had that experience with ours. We have had consistent 120f water temperature even with 38f incoming.

The Truma uses microprocessor-controlled stepless burner management that adjusts the heat output from 20,000 to 60,000 BTU based upon incoming temperature and flow rates.

No, we are not having any problems with our water heater!

The Precision Temp unit has the same type of controls as the Truma unit. Since the Truma appeared after the Precision Temp, it appeared to me that they are a copy of the Precision Temp design. Take a look at both units side by side and you will be surprised at how close their design is.

The facts about these units are that they do have limits as to the temperature rise they are capable of. Look at the specifications for your unit, it will be in there. When there is low pressure and flow they can't run at full bore on the burner, hence the low flow problems. When we experience the low pressure issues, we simply change over to the on board pump and keep on going. The park we stay at in Arizona occasionally has their pressure drop to around 35psi.

People often complain about wasted water waiting for the hot water. Well, they will have the same problem with their tank unit as one still has to wait for the hot water to get there. The longer the distance from the water heater the longer the wait.

Keith

A key issue is propane vs electric:
- Electric: It's tough to get enough juice to keep up with any significant flow, so at best you get lukewarm water.
- Propane: It's tough to match heating output to the water flow.

We had one on our boat and after the first few uses gave up for anything other than dish water where we were filling the sink in one go. Unless you run a steady strong stream of water, it fluctuates from ice cold to scalding.

I do wonder if a small (maybe 1/2 gal) pass thru tank downstream would solve a lot of the issue. Yeah, it wastes little water but the mixing in the tank would cause the temp change at the outlet to be at least more gradual.

I complain about wasting precious dry camping water trying to get the water adjusted so it doesn't burn your skin off or freeze you.

My on demand system has a adjustment knob in the kitchen (isn't that convenient for showers). Once the adjustment knob has been set, the final temperature of the water depends on the flow rate (faster=cooler, slower=hotter).

So doing all this adjustments just to get the water the right temp wastes a huge amount of water. Not a problem if you have full hook-ups. Big problem when dry camping.

I engineered a hot water recirculation system just to try and keep the temperature from fluctuating when turning shower water off to soap up, and then back on to rinse. The recirculation system marginally fixes the fluctuating temperature problem and provides hot water to the shower sooner.

When I had a hot water tank system, I didn't have these problems.

If it was cost effective I would have a tank water heater installed.

This is important to me because I dry camp most of the time and have a very limited supply of fresh water and grey water capacity.

paddykernahan wrote:
I dry camp most of the time and have a very limited supply of fresh water and grey water capacity.

That water supply limitation is what might be the defining issue.

For those who prefer that type of travel, then a tank water heater model is probably the right choice.

For our purposes, the holding tanks are too small (fresh 82, gray 102, black 65) to be nothing more than a convenience used while actually mobile. We are always on full hookups for overnights and destinations, so the premise of continuous, constant temperature hot water is where our demand (Truma) water heater works better for our mode of travel.

Ask any RV tech who has to replace these stupid tankless water heater units for regular one, and they will tell you that they suck