Instant-Hot Tankless Hot water heaters

I did some searching, but i don't see any recent posts about this topic. My family and I are full-timing and my wife especially is tired of running out of hot water. I know we can use the campsite showers which we do on occasion. My question is what are some of the positives/negatives of these types of units? Is it something I can install on my own? it seems pretty straight forward. I am pretty handy. this is the unit we are thinking about getting:

https://www.amazon.com/Girard-2GWHA...2765&sr=1-1&keywords=tankless+water+heater+RV

Which has some mixed reviews on the product. Some say its amazing, some say its a piece of junk.

Our rig is a 2018 Bighorn Traveler 39MB. We really don't intend on doing much if any dry camping to be honest. My wife is more about the experiencing different places than she is about the Camping side of things.

Any suggestion and info are greatly appretiated.
 

jerryjay11

Well-known member
Instant hot water heaters are efficient because they don't store hot water and they provide plenty hot water. When using you do have to let the water run before you'll get hot water to the shower or sink. Girard is a good brand as far as I now. Instant hots are used very often in homes in place of a standing HWH tank.
 

travelin2

Pennsylvania Chapter Leaders-retired
Per a friend of mine who recently purchased a Class A with said water heater, He’s not pleased. They like to stay in State and COE parks many of those only have electric. He says it’s a water hog and not very efficient when “dry” camping. If you’re strictly a FHU guy, then what I just posted is moot..

Another note, our son has a NG fired on demand WH in their house and is happy with its performance. There is a learning curve to maintain a constant flow of hot water however


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cookie

Administrator
Staff member
Just this morning a guy stopped by to ask about my water softener. He told me that he has an on demand water heater and because of high calcium and lime content in the water at some areas they go to, the water heater plugs up.
He went on to tell me it was quite an expensive repair not to mention the inconvenience of not having hot water while waiting for a repair man.
Dunno, just relaying what I was told.

Peace
Dave
 

bwdt

Well-known member
Firstly, how do you like your 39mb? I ordered one that just came off the assembly line and I'm due to pick it up mid April. One thing that concerns me is the small fresh water tank.

As to the on demand hot water heaters. I know of two issues with them, I don't know if its all of them, but it was an issue with the one in my friends MH. First issue is that you have to wait to get the hot water and it waist water while you wait. Next is the fact that if you turn the water down low, meaning low flow, it will shut off and not produce any water. There is a way to solve these issues.

My friends unit had a switch by each sink that you hit when you wanted hot water. This switch would open a valve and allow the water to recirculate back into the fresh water tank for a minute and automatically shut of when it sensed hot water. The second issue was never resolved, his wife use to always run the shower at low flow and it would go cold. If you always run the water at a sufficient rate then it shouldn't be and issue. Home depot has these thermostatic control valves that you can mount on the line, they will allow hot water to always recirculate until hot and shut off and start recirculating when the water cools until its hot again. you will have to add a third return line back to the tank from all sinks and or tubs to make this work.

Another possibility is to add a second hot water heater and run them in parallel to double the hot water capacity.

On another note, from the previous post. It is really simple to set up a pump with tow fittings with two valves and a reservoir to d-calcify the heater. A plug in and let it run for thirty minutes, no outside service necessary. (we did this on my friends unit, and it worked great and cost less than a hundred to build).
 

jbeletti

Well-known member
I've had two in RVs over the years. First was the first-gen Girard. It got changed out a couple of times as they made improvements to their first-gen product. Wife as not impressed.

Now I have the Suburban. Works pretty well but has its pluses and minuses like anything does.

If I had a choice, I'd like to try the Truma.
 

Gary521

Well-known member
Supposedly, the tankless heaters are more efficient. They are but not by much. The tankless heaters require that you flush them out once or twice a year ( at least the residential models do ). In the end, the running costs are about the same. Yes, there is a lag time to get hot water but you will not run out.
 

carl.swoyer

Well-known member
I did some searching, but i don't see any recent posts about this topic. My family and I are full-timing and my wife especially is tired of running out of hot water. I know we can use the campsite showers which we do on occasion. My question is what are some of the positives/negatives of these types of units? Is it something I can install on my own? it seems pretty straight forward. I am pretty handy. this is the unit we are thinking about getting:

https://www.amazon.com/Girard-2GWHA...2765&sr=1-1&keywords=tankless+water+heater+RV

Which has some mixed reviews on the product. Some say its amazing, some say its a piece of junk.

Our rig is a 2018 Bighorn Traveler 39MB. We really don't intend on doing much if any dry camping to be honest. My wife is more about the experiencing different places than she is about the Camping side of things.

Any suggestion and info are greatly appretiated.
Install this just before the shower head. We use this and never run out of hot water. It's called taking a Navy shower. Adjust the water temperature at the spigot after your wet reach up push the valve closed, pushing it open to rinse.
You can also slow the water flow to the shower head with this valve.
.
3febd3d16f1fb018b982f0a5693067b4.jpg


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Bones

Well-known member
We have a family of 4 and manage ok with our water heater. Sometimes we run out but it doesn't take too long to heat back up. We shut the water off at the shower head and run both heat sources. Electric and Propane to help heat the water up quickly. However these showers are not boiling hot showers as I like to call them. It also seems to fill our tub up just fine too. The kids like taking baths. With all this said I would like to change our water heater out to the truma unit. I think it would work well in allowing the DW to take very hot showers and the kids to have a hot bath.
 

JWalker

Northeast Region Director-Retired
We have a family of 4 and manage ok with our water heater. Sometimes we run out but it doesn't take too long to heat back up. We shut the water off at the shower head and run both heat sources. Electric and Propane to help heat the water up quickly. However these showers are not boiling hot showers as I like to call them. It also seems to fill our tub up just fine too. The kids like taking baths. With all this said I would like to change our water heater out to the truma unit. I think it would work well in allowing the DW to take very hot showers and the kids to have a hot bath.

That is odd. Our hot water is extremely hot. We have to warn people to watch our hot water. When showering, it is generally equal parts hot water and cold water just to have a shower that doesn’t burn your shoulders.
 

jayc

Legendary Member
We have never had a tankless water heater, so I can't speak to having used one. My wife and I frequently take back-to-back showers and have never run out of hot water. Another thing to consider is you have a limited amount of space for gray water, so the longer you shower, the more you put into the tank.
 

travelin2

Pennsylvania Chapter Leaders-retired
We, the 2 of us, have never had a lack of hot water but neither of us spend an extensive amount of time showering nor do we have a washer. Even when the granddaughter is along we’ve had plenty. Unless we’re dry camping, our shower habits are the same as at home. Our water is HOT and needs tempered whether showering or washing dishes.


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Bones

Well-known member
That is odd. Our hot water is extremely hot. We have to warn people to watch our hot water. When showering, it is generally equal parts hot water and cold water just to have a shower that doesn’t burn your shoulders.

Yes the water is hot but does not last too long if all 4 are showering. We try to stagger a bit on the showers to give the water heater time to recover. I have had several times where I'm last and I have the hot water on full blast just to get a luke warm shower.
 

MountainDon

Active Member
Tankless water heaters, do not by design have to waste water, they often have a little pump built in to recirculate the water so that in essence the water at your tap is always hot. This however generally involves an installation that was designed for this, some will actually use the cold water line to recirculate the water until the water is hot.

The difference in tanked vs tankless is how you use the water. to get the most usable hot water out of a tanked system you set the temp as high as you can and then mix down at the faucet with the cold water, there by using less of the hotter hot water

With a tankless this is counter productive as the tankless system is designed to ALWAYS provide water at the specified temp. it accomplishes this by throttling the flow. if your input water temp is 40 degrees your hot water output will be significantly decreased because the heater has to raise the temp 80 degrees to get to 120 degrees. If the input is 60 degrees it only has to raise it 60 degrees so your flow is higher

In an RV this is less of an issue to some degree because you likely have less simultaneous use ( so less demand on flow )

Hope this helps

d
 
Here. This is out of Consumer Reports.

Heating water accounts for up to 30 percent of the average home's energy budget. Some makers of gas-fired tankless water heaters claim their products can cut your energy costs up to half over regular storage heaters. So is it time to switch?

Probably not. Gas tankless water heaters, which use high-powered burners to quickly heat water as it runs through a heat exchanger, were 22 percent more energy efficient on average than the gas-fired storage-tank models in our tests. That translates into a savings of around $70 to $80 per year, based on 2008 national energy costs. But because they cost much more than storage water heaters, it can take up to 22 years to break even— longer than the 20-year life of many models. Moreover, our online poll of 1,200 readers revealed wide variations in installation costs, energy savings, and satisfaction.

With the help of an outside lab, we pitted Takagi and Noritz gas-fired tankless water heaters against three storage water heaters. Evan didn't test electric tankless heaters because many can't deliver hot water fast enough to replace a conventional water heater if groundwater is cold. in areas with warm groundwater, most homeowners would need to upgrade their electrical service to power a whole-house tankless model.

Our tests simulated daily use of 76 to 78 gallons of hot water. That's the equivalent of taking three showers, washing one laundry load, running the dishwasher once (six cycles), and turning on the faucet nine times, for a total of 19 draws. While that's considered heavy use compared with the standard Department of Energy test, we think it more accurately represents an average family's habits. We also ran more than 45,000 gallons of very hard water through a tanked model and a Rinnai tankless model to simulate about 11 years of regular use.

Here's what else we found:

Water runs hot and cold
Manufacturers of tankless water heaters are fond of touting their products' ability to provide an endless amount of hot water. But inconsistent water temperatures were a common complaint among our poll respondents. When you turn on the faucet, tankless models feed in some cold water to gauge how big a temperature rise is needed. If there's cool water lingering in your pipes, you'll receive a momentary "cold-water sandwich" between the old and new hot water. And a tankless water heater's burner might not ignite when you try to get just a trickle of hot water for, say, shaving.

Nor do tankless water heaters deliver hot water instantaneously. It takes time to heat the water to the target temperature, and just like storage water heaters, any cold water in the pipes needs to be pushed out. And tankless models' electric controls mean you'll also lose hot water during a power outage.

Up-front costs are high
The tankless water heaters we tested cost $800 to $1,150, compared with $300 to $480 for the regular storage tank types. Tankless models need electrical outlets for their fan and electronics, upgraded gas pipes, and a new ventilation system. That can bring average installation costs to $1,200, compared with $300 for storage-tank models. visit this

Tankless units might need more care
During our long-term testing, an indicator on the tankless model warned of scale buildup. We paid $334 for special valves and a plumber to flush out the water heater with vinegar. Many industry pros recommend that tankless models be serviced once a year by a qualified technician. Calcium buildup can decrease efficiency, restrict water flow, and damage tankless models. Experts suggest installing a water softener if your water hardness is above 11 grains per gallon. Ignoring this advice can shorten your warranty.

Efficient storage models are pricey
We also tested the $1,400 Vertex, a high-efficiency storage water heater by A.O. Smith. The manufacturer claims its installation costs are similar to a regular storage model. But its high cost offsets much of the roughly $70 per year the Vertex will save you. Instead, we recommend buying a conventional storage water heater with a 9- or 12-year warranty. In previous tests, we found that those models generally had thicker insulation, bigger burners or larger heating elements, and better corrosion-fighting metal rods called anodes.

Posted: September 2008 — Consumer Reports Magazine issue: October 2008

So basically Consumer Reports is verifying pretty much everything those of us that have been screwing around with these things have been saying. Believe me, we have seen these products 25 years ago and had all the same issues with them. In fact, most of those have long since been scrapped for more conventional heaters.

Indirect heaters use a boiler to heat a quantity of hot water. The storage tank is super-insulated and has very very low standby loss. The recovery of these units if properly sized will allow you to virtually run hot water all day long.
 
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tomhank

Member
Consider the Ridgeyard contemporary gas tankless water heater if you want unlimited hot water. You can get 12 liters of hot water every minute from this tankless water heater, which is fuelled by liquid propane.
 
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