Community Forums

jamesvinton · 12-01-2011, 09:07 AM

I am considering the installation of a tankless hot water heater in my 2011 Fleetwood Bounder. Anyone out there done this? Any comments

Blaster 22 · 12-01-2011, 09:20 AM

Are you talking about a system like in the stick house or an Aqua Hot?

jamesvinton · 12-02-2011, 05:56 AM

Yes

LadyFitz... · 12-02-2011, 06:51 AM

Besides the Aqua Hot (which is diesel fired and can be legally used only in a diesel powered rig), the only tankless water heaters approved for use in RVs are the propane fired Girard and RV 500. The Girard is a barebones system that has only the basic controls. Most people who dislike the Girard do so because to regulate water temperature, instead of blending hot water with cold water, one has to adjust the water flow; the faster the flow, the lower the water temperature. The RV 500 costs twice as much as the Girard but has more sophisticated temperature controls that maintains a constant water temperature. One can adjust water temperature by blending hot water with cold water.

jamesvinton · 12-02-2011, 07:04 AM

PrecisionTemp.com: For Recreational Vehicles and Boats

Roam America · 12-02-2011, 08:36 AM

While touring a 5th Wheel Manufacturer facility over the summer I asked about having a tank-less HWH. I was told they only raise the water temp about 20 degrees so it is more of an assist than single supply of hot water.

Later on after thinking about it a bit I began to wonder if that were the case how do the stick and brick models provide an endless supply of hot water. So now I'm not sure if what the tour guide said is true or not. After reading the information from the link in he previous post I am ready to call BS on what I was told.

I am full-time and, while I still had my house, on occasion I was known to enjoy a long hot shower. This is not possible in an RV, even with the 12 gallon HWH I have. Thus my thought of having the tank-less HWH.

Any additional info is appreciated.

LadyFitz... · 12-02-2011, 09:09 AM

I'm constantly being amazed by the amount of misinformation being bandied about on the RV forums on tankless water heaters.

Engineer Guy · 12-02-2011, 09:16 AM

'LadyFitz' sounds like she/he nailed the answer above re: RV Applications. I can speak to the Technology of what's going on. I've put a 'Flash' or 'Demand' Heater [Electric] in one our Houses after lots of self-study.

'Block' Flash Heaters input energy rather blindly, and heat Water 'x' degrees. If the Water coming in is colder, or at a 'higher' flow rate, less heating occurs. They're very tricky to use, and really not acceptable to most folks. One has to put in precise Ball Valves for flow rate control; temper Water in a pre-Heater Tank so that it first comes up to a repeatable Temperature; and be ready to tinker with Heater performance. They also require some nominal water flow initially for the Heater to trip on. So, they're not really Water-saving, 'low flow' compatible. For example, Well Water temp varies with Season. That non-fixed Water temp input affects water temp output from Block-style Flash Heaters.

At a much higher price point, sophisticated Flash/Tankless Heaters have all sorts of Sensors to monitor incoming/outgoing Water temp and flow. They make internal adjustments very quickly to ensure a consistent output 'product': Water at the desired temp. For a Sticks/Bricks House, this level of sophistication costs 4 $$$$ figures, typically. All those Sensors and Controls aren't low cost. These same rules apply to RV Water Heaters, so keep them in mind while shopping.

The much-greater Propane BTU requirements also dictate Propane Supply Lines of a specified diameter/capacity, and - at least in Stick/Brick Homes - larger diameter Flues. So, ensure this RV 'infrastructure' is there first to allow a retrofit.

Of course, there's no such thing as a 'Hot Water Heater', since there's no need to heat Hot Water. There's only 'Water Heaters'.

Read up on 'Rinnai' Tankless Water Heaters here. I have no affiliation with any Company.

Rinnai Tankless Water Heaters

Billieg · 12-02-2011, 09:32 AM

Just put a water heater in my stick & brick. Call my friend who is a plumber to ask him which "tankless" one is best. He said none of them. He said he wouldn't install any of them because they don't last and are not dependable.

He said I could buy one of the very best ones for around $2,400 and expect to replace it within 2 - 3 years. He said I would also have to upgrade my wiring to 6 gauge 50 amp to even make it work which would be impossible in a RV.

It's a great idea but not ready for prime time. My new tank water heater works just fine. The one thing I've been thinking about for the RV is a solar system with an extra 10 gal. tank. Here in FL. it would work well.

DrScott · 12-02-2011, 09:36 AM

So they might be tankless cold water heaters???

Seriously, thanks for the info. I am researching them for our stick home.

LadyFitz... · 12-02-2011, 09:57 AM

Quote:

Originally Posted by Engineer Guy

'LadyFitz' sounds like she/he nailed the answer above re: RV Applications. I can speak to the Technology of what's going on. I've put a 'Flash' or 'Demand' Heater [Electric] in one our Houses after lots of self-study.

'Block' Flash Heaters input energy rather blindly, and heat Water 'x' degrees. If the Water coming in is colder, or at a 'higher' flow rate, less heating occurs. They're very tricky to use, and really not acceptable to most folks. One has to put in precise Ball Valves for flow rate control; temper Water in a pre-Heater Tank so that it first comes up to a repeatable Temperature; and be ready to tinker with Heater performance. They also require some nominal water flow initially for the Heater to trip on. So, they're not really Water-saving, 'low flow' compatible. For example, Well Water temp varies with Season. That non-fixed Water temp input affects water temp output from Block-style Flash Heaters.

At a much higher price point, sophisticated Flash/Tankless Heaters have all sorts of Sensors to monitor incoming/outgoing Water temp and flow. They make internal adjustments very quickly to ensure a consistent output 'product': Water at the desired temp. For a Sticks/Bricks House, this level of sophistication costs 4 $$$$ figures, typically. All those Sensors and Controls aren't low cost. These same rules apply to RV Water Heaters, so keep them in mind while shopping.

The much-greater Propane BTU requirements also dictate Propane Supply Lines of a specified diameter/capacity, and - at least in Stick/Brick Homes - larger diameter Flues. So, ensure this RV 'infrastructure' is there first to allow a retrofit.

Of course, there's no such thing as a 'Hot Water Heater', since there's no need to heat Hot Water. There's only 'Water Heaters'.

Read up on 'Rinnai' Tankless Water Heaters here. I have no affiliation with any Company.

Rinnai Tankless Water Heaters

I looked at the Rinnai water heaters and was surprised to learn they are approved for use in mobile homes. No mention was made of RVs. Except for the Rennai, all the tankless water heaters I've looked into to specifically forbid using them in mobile homes and RVs and that installing them in one or the other would void the warranty. The warranty description on Rennai's website was short and vague. Even if the warranty wasn't a concern, safely installing one in an RV would be a pain.

What's with the she/he? What part of the Lady in my user id didn't you get?

Roam America · 12-02-2011, 11:00 AM

Quote:

Originally Posted by LadyFitz...

I'm constantly being amazed by the amount of misinformation being bandied about on the RV forums on tankless water heaters.

Do you care to elaborate? It is OK to make a statement like this, but what about supporting info.

jspande · 12-02-2011, 11:23 AM

Lots of totally false info here. I installed and used a Precision Temp tankless water heater in my fifth wheel several years ago (until I upgraded to the Precision Temp hydronic heating system called "TwinTemp").

1. It's reliability was just fine.
2. It most certainly will heat water as hot as you would ever want it (for safety reasons), and it'll produce such hot water all day long.

In fact, there may be a problem on the low flow end of things, but not on insufficient heating capacity. All tankless heaters will have a minimum flow, below which the burner will cut out. This can be a problem in climates where the inlet water temperature is too warm, and dry campers will probably have issues since it complicates water conservation.

LadyFitz... · 12-02-2011, 11:29 AM

Quote:

Originally Posted by K-Star

Do you care to elaborate? It is OK to make a statement like this, but what about supporting info.

Look at any thread on tankless water heaters and you find posts from people who know only about residential and portable tankless water heaters and do not know that none of them are approved for RVs. Nor are they aware the only ones that are are the Aqua Hots (and those are legal only on diesel powered RVs), The RC 500 and and the Girard (the latter two are designed to fit in the hole occupied by a conventional tank type water heater). Many who complained about the Girard's got them preinstalled in their RVs and didn't bother to read the instructions on how to use them, then assumed they were junk (they work fine albeit differently; I actually got to see one in operation).

Then you have the naysayers who either know nothing about them and automatically assume their junk, are only familiar with the low yield ones once used in Europe (btw, tankless water heaters are more popular in Europe than the tank types and have been around for a long time; so much for the claim that it's new technology), or got a unit in their stick & bricks that wasn't properly sized for the demand.