Tankless Water heaters for RV

[ankie3467]

I am hoping someone can help me. We are looking to buy a new 5th wheel this spring. We have narrowed it down to 2 brands. One has a tankless water heater. And the other has a 10 gallon LP/Electric one. 99% of the time we are dry camping, we cant afford to waste water. Does anyone have any experience with these Tankless water heaters?

[SSteve]

ankie,

I don't have a tankless heater, but I am familiar with them.

Is the tankless you're faced with Electric or propane or both?
Do you know the Brand and/or model?

The following assumes all other things are equal (insulation, distance from heater to faucets, etc.).

You'll use about the same energy to heat the water. The difference is that with the tankless, use use the energy all at once instead of slowly, over time.

If the heater is propane fired, it will use less gas over time than a regular propane heater. This is because you're not keeping water hot. You make it hot when needed. Uses lots of gas to do this on demand, but again, over time, less.

If its electric, its energy demand (and savings) are similar to propane. The main difference is that the GOBS of electricity you'll need to run it may over tax the supply at the electric hook-up.

If it works on propane (but, not electric), I'd be interested since it can, over time, use less gas. If it will work with a 30 amp supply (and not make you turn everything else off) I'd be interested as well, especially if my campground arrangements include metered electric.

But, if dry camping is your major gig, I'd stay away from an ELECTRIC powered tankless heater.

I'd love to hear the make/model.

Apologies for the ramble.
Steve

[ankie3467]

I was able to grab this information--It is a Girard product, used 100% propane and 12 volt ignition. Wildcat is putting these in all new models. My fear is running out of water trying to get hot water!

[Brigadoon]

I would be more concerned about the propane consumption.

[jablair]

Don't have one myself but you might check out the 'RV500' by Precision Temp at 'PrecesionTemp.com'. It is propane, may be propane and electric just don't remember. It was specifically designed for RV and for replacement to fit in the area of the standard Atwood or Suburban water heaters. On others forums user have had good comments for the RV500.

[Ottawa]

Grey water may be a problem, when you do not have the limitations of a 6 or 10 gal of hotwater to tell you the shower is over.

[SSteve]

Quote:

I would be more concerned about the propane consumption.

Worry not about propane consumption.


As I said in my op, if all other things are equal...


You will use the same amount of propane to heat a given quantity of water. The differences are:


1. You will NOT be keeping the water hot between uses. Yep, you can turn off a tank-type heater or the propane and get nearly this same effect, but you'll have to remember to turn it back on an hour or two before you need it. You'll use the same amount of propane.


2. You'll be even better able to monitor your propane supply, since you don't have the heater keeping the water in the tank hot (read using propane) while you're not using the hot water. You won't wake up in the morning and find a gas level less than you had the night before, unless of course, you used gas.


That means you're likely to NOT use as much gas as you might with a tank-type. The main issue when deciding between a tank and tankless heater is initial cost. The tankless is doubtless significantly more expensive. But, if its already installed in the RV....


Steve

See http://greenrvproducts.com/girard-ta...-water-heater/

Some of the comparisons aren't really relevant (modern tank heaters don't have pilots), but some good info.

[idenphones]

We have a tankless unit at our stick house and it definately saves propane.

The only thing that you need to remember is that it does take a few seconds to get the water hot and you need to turn the water faucet on to give it a good flow.

The water heater does not like dribbling out of the faucet and it may not fire.

Other than that.......................Love it! Filled the hot tub one day with it. 500 gallons, no sweat!

[jspande]

I installed a Precision Temp RV500 in my 5th wheel a few years ago (I've since changed to the Precision Temp hydronic space heating system ("TwinTemp") which replaces the water heater as well.

The tankless system had a lot of advantages over the standard RV water heater, being much more efficient (tank style has around 55 to 60 % efficiency I believe), much quieter, besides of course the "endless hot water".

But I did have to remove the flow resrticter in the shower head to increase flow to get it to fire reliably, and even then, in summer (here in So Cal with triple digit temps) the "cold" water supply was warm enough that I had to open the lavy hot faucet along with the shower to get sufficient flow to get a steady temperature (burner couldn't throttle down enough and so hot water would cycle on and off - not good for a shower).

[paz]

We don't have a tankless heater, but others who have replied to this thread confirm what I have read - it takes nearly full flow to get the heater to fire, and it takes a few seconds for the hot water to clear the cold water out of the line when you turn it on. For those reasons, I don't think a tankless hot water heater would be what you want if you boondock a lot and want to save water. When we boondock, we take Navy showers and it wouldn't be too pleasant to get a shot of cold water every time you turn the water off and back on.

[a10koaksfed]

Has anyone specifically installed the Girard Tankless RV hotwater heater? It is made to install in the area where the current Atwood or Suburban Hot water heater is located. RV specific design. My DW needs HOT WATER and can't stand navy showers.

Looking for info from someone who already has this system. Thank you.

[jspande]

Paz, I concur that tankless water heaters are probably not a good choice for water saving applications like Boondocking. Much as I like the idea their advantages, such as efficiency and quit operation (and they never start up in the middle of the night unless you get up and draw hot water), I have reluctantly concluded that they just aren't ideal for RV's.

I looked at the website for the Girard unit (which I hadn't heard of before). It raised some red flags for me. First, it has a maximum btu rating of 34,000 (the PrecisionTemp unit I had was 55,000 btu, so obviously could heat more (or colder) water to desired temp).

Moreover it had only two burner rates (27,000 and 34,000 btu) while the PrecisionTemp had a proportioning gas valve. In other words, the PrecisionTemp gives a constant temp hot water over a wide range of flows, while the Girard has just two heat levels and you control the hot water temperature by varying the water flow. So you'd have to settle for whatever shower flow the temperature of the inlet (cold) water happened to be. And if someone turned on a hot faucet while you were in the shower, the tempurature would drop.

[Clay L]

I have seen a couple of posts by people that have installed the Girard system. They said you control the temperature by turning the cold water faucet off and regulating the temperature by controlling the flow with the hot water faucet.
That convinced me I don't want one.

[a10koaksfed]

Thank you all for the Girard specific info. Seems that it is a hot H2O solution still under development.