Questions Regarding Tankless Hot Water Heaters and Venting

[khantroll]

Hi all, I have a couple of questions regarding tankless hot water heaters. I am in the process of renovating my RV, and one of the things that I'd like to do is upgrade to a tankless hot water heater. Initially, I thought my only choice was the Girard Tankless Hot Water heater, but I have seen several videos of vans, buses, and even fifth wheels using one of the small cabin residential tankless hot water heaters. Example: https://www.amazon.com/Ridgeyard-4-75GPM-Propane-Tankless-Instant/dp/B01N9TWZJH/ref=sr_1_6?ie=UTF8&qid=1493589337&sr=8-6&keywords=d+batteries+tankless  These are less then half the cost of the Girard., and somewhat smaller. 

As a follow up, would it be possible to use a plumbing vent as a flue? 

Thanks in advance for your thoughts!

[Ranger Smith]

Problem with is you get what you pay for. When it breaks where do you get parts. I had a Rv with a Girard water heater and we took it out and put in a conventional one. It was very finicky. Open the handle less for more hot water. We were lucky if we coud get it set right to take a shower. Little too warm . . . Little too cool. It is also dependent on incoming water temperature.

We scrapped it and went back to an Atwood.

[baloo]

I was also interested in a tankless heater -- but not to replace my present 6GAL propane water heater, but to use in tandem with it.

Since our water heater is only 6 gallons, in the event that we would need more hot water in a short amount of time, I'd like the tankless to kick in to meet sudden extra demans.  If it's only about $200, it seems worth the money for just those times when more is needed.

It certainly would be cheaper than installing a 10 or 15gal tank, in that there would not be the need to heat up and maintain the heat in a whole 10/15 Gal holding tank as it sits there unused.

[khantroll]

Ranger Rick: The poor reviews of the Girard are one of the reasons I'm looking at other avenues. As for parts availability,  I totally see your point; however, in my home area, I'd have to order any part other then plumbing valves or an anode rod for a regular hot water heater. 

Baloo: here is a guy who did something similar to what you are proposing: 

 

Thanks!

[baloo]

Khantrall, excellent info. Thanks.

[Chad Heiser]

The current gold standard in on demand water heaters for RV's is Truma.  They have been in the European market for a while and have been moving into the Armerican market over the last few years.  Many manufacturers now offer it as an option.  I have one and am very happy with it. It has all the benefits of an on demand system and has engineered out the draw backs as described above with temperature issues.  Truma did this by adding a small temperature stabilizer tank in the unit.  They are not the cheapest option out there, but they are the best.

[khantroll]

Hi Chad, 

Can you purchase a Truma unit? I thought they were only available as options in specific RVs. If you can, how much are we talking? 

Thanks!

[Kirk W]

I was just looking at them and found this list of dealers in this part of the US.

In doing searches, I find that there are now at least 4 manufacturers in the US with Suburban, Atwood, and Precision Temp also offering them.

[khantroll]

I obviously can't compare any of them based on performance (as I have never had any of them), but: 

Truma AquaGo: 60000 BTU - 2 gallons per minute flow rate - $1100

Atwood Tankless Hot Water Heater: 50000 BTU - 1.5 gallons per minute - $825

Suburban IW60: 60000 BTU - 1-2 gallons per minute: $610

Precision Temp RV-550:  55000BTU - 1 gallon per minute: $1070

Girard GSWH-2: 42000BTU -  1.6 gallons per minute: $514

 

Based on the above, if I had to choose one of those I think I'd opt for the Suburban, but just for the sake of comparison: 

Ridge Yard 12L: 80000BTU - 3.2 gallons per minute: $143

[Chad Heiser]

3 hours ago, khantroll said:

Hi Chad, 

Can you purchase a Truma unit? I thought they were only available as options in specific RVs. If you can, how much are we talking? 

Thanks!

The Truma's are available in the aftermarket.  I have not priced one out, but Jack Mayer had one installed in his New Horizon's from the aftermarket.  He wrote a review on it after using it for some time (which you can see here) and was very pleased with its performance.  When I ordered my new DRV, I opted to have the Truma installed in it and am very happy with it.

[baloo]

7 hours ago, khantroll said:

I obviously can't compare any of them based on performance (as I have never had any of them), but: 

Truma AquaGo: 60000 BTU - 2 gallons per minute flow rate - $1100

Atwood Tankless Hot Water Heater: 50000 BTU - 1.5 gallons per minute - $825

Suburban IW60: 60000 BTU - 1-2 gallons per minute: $610

Precision Temp RV-550:  55000BTU - 1 gallon per minute: $1070

Girard GSWH-2: 42000BTU -  1.6 gallons per minute: $514

 

Based on the above, if I had to choose one of those I think I'd opt for the Suburban, but just for the sake of comparison: 

Ridge Yard 12L: 80000BTU - 3.2 gallons per minute: $143

Khantroll, I have to agree that the cheaper heaters, as on EBay for example, have higher GPM than those 2-4X as expensive.  If you put one of the cheaper ones in tandem with an exisiting conventional water heater, they should be rarely used (only when you max out the 6, 10, or 15GAL capacity), so thus not overly stressed -- and thus not leaving you stranded should the cheap version fail.

I think we all like to tout buying quality, but after a while, one realizes that it just doesn't matter if you have a Vacheron-Constantin and drive a Rolls, when you just want to go to the grocery store and back in your 87 Tercel with a Timex.  We aren't talking about traveling in outer space, where you have no chance to pull over to a Lowes, ya know.

[LindaH]

On ‎4‎/‎30‎/‎2017 at 3:15 PM, Ranger Smith said:

Problem with is you get what you pay for. When it breaks where do you get parts. I had a Rv with a Girard water heater and we took it out and put in a conventional one. It was very finicky. Open the handle less for more hot water. We were lucky if we coud get it set right to take a shower. Little too warm . . . Little too cool. It is also dependent on incoming water temperature.

We scrapped it and went back to an Atwood.

We, too, have a Girard tankless water heater which I hate.  I'd love to replace it with a "regular" water heater. 

How much did it cost you to make the switch?  You can PM me if you wish. 

[baloo]

9 minutes ago, LindaH said:

We, too, have a Girard tankless water heater which I hate.  I'd love to replace it with a "regular" water heater. 

How much did it cost you to make the switch?  You can PM me if you wish. 

Linda -- as per above posts, been thinking about adding a cheap tankless IN TANDEM (as per the OP's video).

Can you give more detail about what you hate about your tankless heater? Too hot? Breaks down? etc.?

Thanks.

[Ranger Smith]

38 minutes ago, LindaH said:

We, too, have a Girard tankless water heater which I hate.  I'd love to replace it with a "regular" water heater. 

How much did it cost you to make the switch?  You can PM me if you wish. 

I believe it was 300 to 400 dollars to buy a regular water heater. I installed it myself

[LindaH]

5 hours ago, Ranger Smith said:

I believe it was 300 to 400 dollars to buy a regular water heater. I installed it myself

Thanks.  We'd have to have someone install it, so that would probably at least double the price.  We may get a quote to do this when we take our RV in for servicing before we head out for our winter travels.

[LindaH]

6 hours ago, baloo said:

Linda -- as per above posts, been thinking about adding a cheap tankless IN TANDEM (as per the OP's video).

Can you give more detail about what you hate about your tankless heater? Too hot? Breaks down? etc.?

Thanks.

We did have a problem when it totally quit working.  Of course, we were on our way home and had no place to get it repaired until we got home!

But that was a one-time occurrence.  What I don"t like about it is that it won't keep a constant temperature when running water.  We take Navy showers even when in an RV park (which isn't often).  When we turn the water back on to rinse off, We've learned to step back, otherwise we get sprayed with cold water!  And even once the water gets hot again, the temperature fluctuates.  Never had that problem with a regular water heater.

[57becky]

When our Suburban 12 gallon water heater developed a leak last year, I considered replacing it with a Suburban tankless unit.  The downside of this, which changed my mind, was in replacing a conventional unit with the tankless, they have an annual maintenance requirement that necessitates access to the rear of the water heater, and on our rig, that would be impossible to do.  So, before you jump at the tankless option, be sure to check everything about the unit you want, and what is needed for maintenance.

[Chad Heiser]

45 minutes ago, LindaH said:

We did have a problem when it totally quit working.  Of course, we were on our way home and had no place to get it repaired until we got home!

But that was a one-time occurrence.  What I don"t like about it is that it won't keep a constant temperature when running water.  We take Navy showers even when in an RV park (which isn't often).  When we turn the water back on to rinse off, We've learned to step back, otherwise we get sprayed with cold water!  And even once the water gets hot again, the temperature fluctuates.  Never had that problem with a regular water heater.

You won't have that problem with a Truma on demand heater either.  Their system has resolved this issue that other tank-less water heaters have.

[LindaH]

14 hours ago, Chad Heiser said:

You won't have that problem with a Truma on demand heater either.  Their system has resolved this issue that other tank-less water heaters have.

Well, if we replace our current water heater, it will be with an Atwood 6-gallon propane-only water heater, not another tankless.

[lockmup68]

Truma is $1495 installed.

[Chad Heiser]

Luckily for me it was a lot cheaper than that OEM.

[Jack Mayer]

9 hours ago, Chad Heiser said:

Luckily for me it was a lot cheaper than that OEM.

Yeah, it is more likely in the $700-800 range when ordering it in a rig. Retrofit will be more, of course. 

The Truma works very, very well. I've got two years on mine and it has been reliable and maintenance free. There are some "nuances" in its use which I cover in my review document that Chad referenced above. Here it is again...LINK.

[khantroll]

Hi all, I decided against the the residential tankless hot water heater; in my particular rig, it would have required major modification that I wasn't comfortable with. So I made some phone calls, and I found a used Atwood On-Demand hot water heater for a very affordable price. 

If someone has a rig with large storage bays where they could mount that residential heater, or something that isn't basically foam and plywood like my rig is, the heater could work.