Tankless propane hot water heaters - R-pod Owners Forum

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offgrid

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Joined: 23 Jul 2018
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Posts: 5290

Topic: Tankless propane hot water heaters
Posted: 10 Feb 2019 at 5:50am

The tankless electric heaters essentially adjust instantaneously now. Precise to a degree or better with no noticeable lags or temp variations. Can’t speak for the gas ones but they’re probably pretty close to that. Which one makes the most sense depends on the costs of energy in your area, for me electric is cheapest.

With any tankless system the peak heating capacity has to be selected to meet your max flow rate and inlet and outlet water temps. You can do this calc yourself or use a table provided by the manufacturer. Tankless systems will probably use more power (electric or gas) than any other appliance in your house, but they will use less energy (power over time) than a tank water heater because when you’re not using water they’re off.

If anyone is contemplating any significant home replumbing you should take a look at modern pex based water distribution systems first, plumbing has changed dramatically and for the better in the last few years. I had to replace all my plumbing distribution after Matthew and am amazed at how much easier it is now, less expensive, more compact and convenient, leak free, and with faster water delivery.

1994 Chinook Concourse
1995 RV6A Experimental Aircraft
2015 Rpod 179 - sold

lostagain

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Joined: 06 Sep 2016
Location: Quaker Hill, CT
Online Status: Offline
Posts: 2586

Posted: 09 Feb 2019 at 7:59pm

My daughter has a tankless system that they installed about 12 years ago and they've been pretty happy with it. But it's a high BTU system for their small 4 br. house. The ambient water temp is not so cold so the amount of heating that has to be done is well within the capacity of their heater. The heater in my sister-in-law's apartment works well but they have the flow rate set at the minimum and the temp at max. Like my daughters, they have a starting temp that is not too cold.

I looked into a tankless system when I lived in northern NJ and decide against it because in the winter the starting water temp was just too cold for all but the most costly heaters.

For us, we're sticking with our Suburban 6 gal for our Pod. We hardly heat water anyway and it is more than adequate for our needs. The extra weight is of no consequence in our already light trailer.

Never leave footprints behind.
Fred & Maria Kearney
Sonoma 167RB
Our Pod 172
2019 Ford F-150 4x4 2.7 EcoBoost

GlueGuy

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Joined: 15 May 2017
Location: N. California
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Posts: 2627

Posted: 09 Feb 2019 at 7:18pm

We have two water heaters in our house (it was built in two different stages). The south (original side) has a conventional tank-style water heater. We've replaced it a couple of times over the years. It works fine and is steady. Nice hot water.

The north (addition side) has a tankless heater. Understand first that this tankless heater was new in 1995. We've never replaced it. It does not supply a "lot" of water, but it does OK. By itself, it supplies hot water to one or two sinks. However, if you need to fill a tub, or take a shower, you need to enable the "booster". The booster is electric and uses something like 6KW of juice (~~ 30 amps at 220 volts). I can hear the electric meter spin when that puppy is on.

I'm sure tankless heaters have improved in the 25 or so years since that thing was made. If I had to do over again, I would install point-of-use tankless heaters in the two bathrooms. As it is, you have to wait about 3 days for the hot water to make it to the sink.

bp
2017 R-Pod 179 Hood River
2015 Ford F150 SuperCrew 4WD 3.5L Ecoboost

lostagain

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Joined: 06 Sep 2016
Location: Quaker Hill, CT
Online Status: Offline
Posts: 2586

Posted: 09 Feb 2019 at 6:36pm

I looked at some of the tankless RV water heaters in Amazon. The issues in this review were not uncommon:

"I have a Girard tankless water heater in my 2014 Jayco Motorhome. It is by far, the worst water heater that I have ever had in my 35+ years of camping. I am not sure how the Precision Temp RV-550 Tankless Water Heater works, but if it is anything like the Girard, Don't get it. I am having the tankless water heater removed and replaced with a standard 6 gallon Propane/Electric Water heater at a cost of $1700.
The tankless water heater will not hold the temperature that you adjust it to and the water fluctuates from scalding hot to ice cold over and over again. This is because the water pressures in campgrounds fluctuates all the time and tankless water heaters do not work well because of this. This is extremely dangerous when taking a shower.
Take my advice, until the tankless water heater companies address the fluctuating water temperature problems, stay with the standard 6 or 10 gallon water heaters."

It looks like the technology needs a little fine tuning. The complaint in this review is exactly what I experienced with my first tankless water heating system back in 2002 in an apartment where I lived.

Never leave footprints behind.
Fred & Maria Kearney
Sonoma 167RB
Our Pod 172
2019 Ford F-150 4x4 2.7 EcoBoost

offgrid

Senior Member

Joined: 23 Jul 2018
Online Status: Offline
Posts: 5290

Posted: 09 Feb 2019 at 2:36pm

For a luxury class B the Truma makes lots of sense, they are tight on space and what's a thousand dollars more on a new $100K plus RV? As a retrofit for budget conscious travel trailer owners, not so much.

1994 Chinook Concourse
1995 RV6A Experimental Aircraft
2015 Rpod 179 - sold

lostagain

Senior Member

Joined: 06 Sep 2016
Location: Quaker Hill, CT
Online Status: Offline
Posts: 2586

Posted: 09 Feb 2019 at 1:47pm

If you had to replace both your heater and water heater, something like the Truma Comfort Plus could really make some sense. The question is whether it would be worth it in an older Pod. If you planned on keeping it a long time after the switch it may be cost effective, but if you tend to turn over your RV's every so often, it may not be such a good idea.

Never leave footprints behind.
Fred & Maria Kearney
Sonoma 167RB
Our Pod 172
2019 Ford F-150 4x4 2.7 EcoBoost

offgrid

Senior Member

Joined: 23 Jul 2018
Online Status: Offline
Posts: 5290

Posted: 09 Feb 2019 at 9:29am

The space around the current water heater in my 179 is under the bed so is wasted anyway. And you have to have clearances for the hot flue gasses so I'm not sure its either needed or desirable to have a much smaller tankless unit.

If money is no object you can get a Truma Comfort Plus and remove both the current furnace and water heater, it performs both functions. Its a hybrid design with a 2.6 gallon tank to address lostagain's point regarding water waste while the on demand system heats up after sensing water flow. It will save about 50 lbs total weight including the the net water weight savings, plus the space saving from replacing both existing units.

And, the furnace section is actually quiet, addressing another issue that has prompted some members here to add heat exchangers to the hot water systems. Only catch? Ya have to have about $1500 burning a hole in your pocket...

1994 Chinook Concourse
1995 RV6A Experimental Aircraft
2015 Rpod 179 - sold

lostagain

Senior Member

Joined: 06 Sep 2016
Location: Quaker Hill, CT
Online Status: Offline
Posts: 2586

Posted: 09 Feb 2019 at 8:41am

Making room for Bourbon is a non-sequitur for me. I don't like it and don't drink it. Now, if you were talking about tequila Herradura Reposado that'd be a horse of a different color.

Gaining storage from a smaller tankless water heater makes the equation change and since it is a question of trade-offs, that may be the balance tipper. The other issue is cost. Many of the tankless systems are pretty pricey and for those of us on a limited budget, it just doesn't make sense, even if we are in need of replacement of the exiting Suburban water heater.

Never leave footprints behind.
Fred & Maria Kearney
Sonoma 167RB
Our Pod 172
2019 Ford F-150 4x4 2.7 EcoBoost

Motor7

Senior Member

Joined: 09 Jan 2019
Location: E. TN
Online Status: Offline
Posts: 196

Posted: 09 Feb 2019 at 8:11am

I don't think they are done getting smaller yet. The RV ones now are designed to fit the opening of the old tanked ones so that is why they are so large. Sooner or later, a mfg will come up with a more compact gas fired one that will take up maybe 1/3 of the present designed compartment. Then we will gain storage and lose some dead weight. Just think of how many bottles of Bourbon could fit in there(that's Not dead weight)! Until then, I'm not in a hurry to swap mine out, but just daydreaming about the future.

2016 R-Pod 176T

lostagain

Senior Member

Joined: 06 Sep 2016
Location: Quaker Hill, CT
Online Status: Offline
Posts: 2586

Posted: 09 Feb 2019 at 7:13am

If weight is really that critical that you can't manage the weight of the 6 gallons of water in the water heater, then you've probably got too much stuff in your trailer and may want to consider getting a bigger one. I did a little poking around on the Internet and found a tankless water heater that is a direct swap for the Suburban on Amazon. It runs about $600. It weighs a little less than half the weight of the Suburban, thus saving you an additional 24 lbs. [The Suburban cost almost $500.] https://www.amazon.com/Girard-2GWHAM-Demand-Tankless-Heater/dp/B019BWN8E2/ref=sr_1_24?crid=KZEQQ40ZYQX9&keywords=tankless+water+heater+for+rv+propane&qid=1549717924&s=gateway&sprefix=tankless+water+heater+for+rv%2Caps%2C201&sr=8-24

Tankless water heaters are activated by flow, so you have to run it long enough to get the flow hot. I'm using one right now every day for a shower and it takes quite a bit of water passing through the system before the water from the heater gets hot enough to be useful. That amount will depend on the starting temperature of the water, the distance to the point of use, the flow rate, and the efficiency of the heat exchanger. So, you'd want to compare how much water you will use to get usable hot water from both the tankless and tank systems.

My suspicion, based on using one every day here in Colombia, is that you'd use pretty close to a couple of quarts to a gallon before getting useable hot water. And if you take mariner's showers, you are going to have to reheat each time you turn the water off and on. [The amount of reheating depends on how long it's turned off and the ambient temperature of the fresh water in the tank.] In contrast, the tank gives you nearly instant hot water with each turning off and on, the delay being the distance from the tank to the shower and how fast the hot water in the line cools off.

Given the limited tankage, both gray and fresh, and the higher level of water use for a tankless water heater, if you boondock, such a system may not be the best option. On the other hand, if you tend to stay in RV parks with full hookups and don’t have to worry about a limited supply of water and gray water tankage, then such a system could be ideal.

So, the decision really depends on how you use your shower and sink, whether the extra use of water needed to get useable hot water is more efficient than lugging around an extra 65 lbs. of water and water heater for the tanked system. I'd be interested in your experience if you change out your unit for a tankless, so please let us know.

Never leave footprints behind.
Fred & Maria Kearney
Sonoma 167RB
Our Pod 172
2019 Ford F-150 4x4 2.7 EcoBoost

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offgrid Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 23 Jul 2018 Online Status: Offline Posts: 5290	Topic: Tankless propane hot water heaters Posted: 10 Feb 2019 at 5:50am
	The tankless electric heaters essentially adjust instantaneously now. Precise to a degree or better with no noticeable lags or temp variations. Can’t speak for the gas ones but they’re probably pretty close to that. Which one makes the most sense depends on the costs of energy in your area, for me electric is cheapest. With any tankless system the peak heating capacity has to be selected to meet your max flow rate and inlet and outlet water temps. You can do this calc yourself or use a table provided by the manufacturer. Tankless systems will probably use more power (electric or gas) than any other appliance in your house, but they will use less energy (power over time) than a tank water heater because when you’re not using water they’re off. If anyone is contemplating any significant home replumbing you should take a look at modern pex based water distribution systems first, plumbing has changed dramatically and for the better in the last few years. I had to replace all my plumbing distribution after Matthew and am amazed at how much easier it is now, less expensive, more compact and convenient, leak free, and with faster water delivery.
	1994 Chinook Concourse 1995 RV6A Experimental Aircraft 2015 Rpod 179 - sold

lostagain Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 06 Sep 2016 Location: Quaker Hill, CT Online Status: Offline Posts: 2586	Posted: 09 Feb 2019 at 7:59pm
	My daughter has a tankless system that they installed about 12 years ago and they've been pretty happy with it. But it's a high BTU system for their small 4 br. house. The ambient water temp is not so cold so the amount of heating that has to be done is well within the capacity of their heater. The heater in my sister-in-law's apartment works well but they have the flow rate set at the minimum and the temp at max. Like my daughters, they have a starting temp that is not too cold. I looked into a tankless system when I lived in northern NJ and decide against it because in the winter the starting water temp was just too cold for all but the most costly heaters. For us, we're sticking with our Suburban 6 gal for our Pod. We hardly heat water anyway and it is more than adequate for our needs. The extra weight is of no consequence in our already light trailer.
	Never leave footprints behind. Fred & Maria Kearney Sonoma 167RB Our Pod 172 2019 Ford F-150 4x4 2.7 EcoBoost

GlueGuy Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 15 May 2017 Location: N. California Online Status: Offline Posts: 2627	Posted: 09 Feb 2019 at 7:18pm
	We have two water heaters in our house (it was built in two different stages). The south (original side) has a conventional tank-style water heater. We've replaced it a couple of times over the years. It works fine and is steady. Nice hot water. The north (addition side) has a tankless heater. Understand first that this tankless heater was new in 1995. We've never replaced it. It does not supply a "lot" of water, but it does OK. By itself, it supplies hot water to one or two sinks. However, if you need to fill a tub, or take a shower, you need to enable the "booster". The booster is electric and uses something like 6KW of juice (~~ 30 amps at 220 volts). I can hear the electric meter spin when that puppy is on. I'm sure tankless heaters have improved in the 25 or so years since that thing was made. If I had to do over again, I would install point-of-use tankless heaters in the two bathrooms. As it is, you have to wait about 3 days for the hot water to make it to the sink.
	bp 2017 R-Pod 179 Hood River 2015 Ford F150 SuperCrew 4WD 3.5L Ecoboost

lostagain Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 06 Sep 2016 Location: Quaker Hill, CT Online Status: Offline Posts: 2586	Posted: 09 Feb 2019 at 6:36pm
	I looked at some of the tankless RV water heaters in Amazon. The issues in this review were not uncommon: "I have a Girard tankless water heater in my 2014 Jayco Motorhome. It is by far, the worst water heater that I have ever had in my 35+ years of camping. I am not sure how the Precision Temp RV-550 Tankless Water Heater works, but if it is anything like the Girard, Don't get it. I am having the tankless water heater removed and replaced with a standard 6 gallon Propane/Electric Water heater at a cost of $1700. The tankless water heater will not hold the temperature that you adjust it to and the water fluctuates from scalding hot to ice cold over and over again. This is because the water pressures in campgrounds fluctuates all the time and tankless water heaters do not work well because of this. This is extremely dangerous when taking a shower. Take my advice, until the tankless water heater companies address the fluctuating water temperature problems, stay with the standard 6 or 10 gallon water heaters." It looks like the technology needs a little fine tuning. The complaint in this review is exactly what I experienced with my first tankless water heating system back in 2002 in an apartment where I lived.
	Never leave footprints behind. Fred & Maria Kearney Sonoma 167RB Our Pod 172 2019 Ford F-150 4x4 2.7 EcoBoost

offgrid Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 23 Jul 2018 Online Status: Offline Posts: 5290	Posted: 09 Feb 2019 at 2:36pm
	For a luxury class B the Truma makes lots of sense, they are tight on space and what's a thousand dollars more on a new $100K plus RV? As a retrofit for budget conscious travel trailer owners, not so much.
	1994 Chinook Concourse 1995 RV6A Experimental Aircraft 2015 Rpod 179 - sold

lostagain Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 06 Sep 2016 Location: Quaker Hill, CT Online Status: Offline Posts: 2586	Posted: 09 Feb 2019 at 1:47pm
	If you had to replace both your heater and water heater, something like the Truma Comfort Plus could really make some sense. The question is whether it would be worth it in an older Pod. If you planned on keeping it a long time after the switch it may be cost effective, but if you tend to turn over your RV's every so often, it may not be such a good idea.
	Never leave footprints behind. Fred & Maria Kearney Sonoma 167RB Our Pod 172 2019 Ford F-150 4x4 2.7 EcoBoost

offgrid Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 23 Jul 2018 Online Status: Offline Posts: 5290	Posted: 09 Feb 2019 at 9:29am
	The space around the current water heater in my 179 is under the bed so is wasted anyway. And you have to have clearances for the hot flue gasses so I'm not sure its either needed or desirable to have a much smaller tankless unit. If money is no object you can get a Truma Comfort Plus and remove both the current furnace and water heater, it performs both functions. Its a hybrid design with a 2.6 gallon tank to address lostagain's point regarding water waste while the on demand system heats up after sensing water flow. It will save about 50 lbs total weight including the the net water weight savings, plus the space saving from replacing both existing units. And, the furnace section is actually quiet, addressing another issue that has prompted some members here to add heat exchangers to the hot water systems. Only catch? Ya have to have about $1500 burning a hole in your pocket...
	1994 Chinook Concourse 1995 RV6A Experimental Aircraft 2015 Rpod 179 - sold

lostagain Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 06 Sep 2016 Location: Quaker Hill, CT Online Status: Offline Posts: 2586	Posted: 09 Feb 2019 at 8:41am
	Making room for Bourbon is a non-sequitur for me. I don't like it and don't drink it. Now, if you were talking about tequila Herradura Reposado that'd be a horse of a different color. Gaining storage from a smaller tankless water heater makes the equation change and since it is a question of trade-offs, that may be the balance tipper. The other issue is cost. Many of the tankless systems are pretty pricey and for those of us on a limited budget, it just doesn't make sense, even if we are in need of replacement of the exiting Suburban water heater.
	Never leave footprints behind. Fred & Maria Kearney Sonoma 167RB Our Pod 172 2019 Ford F-150 4x4 2.7 EcoBoost

Motor7 Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 09 Jan 2019 Location: E. TN Online Status: Offline Posts: 196	Posted: 09 Feb 2019 at 8:11am
	I don't think they are done getting smaller yet. The RV ones now are designed to fit the opening of the old tanked ones so that is why they are so large. Sooner or later, a mfg will come up with a more compact gas fired one that will take up maybe 1/3 of the present designed compartment. Then we will gain storage and lose some dead weight. Just think of how many bottles of Bourbon could fit in there(that's Not dead weight)! Until then, I'm not in a hurry to swap mine out, but just daydreaming about the future.
	2016 R-Pod 176T

lostagain Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 06 Sep 2016 Location: Quaker Hill, CT Online Status: Offline Posts: 2586	Posted: 09 Feb 2019 at 7:13am
	If weight is really that critical that you can't manage the weight of the 6 gallons of water in the water heater, then you've probably got too much stuff in your trailer and may want to consider getting a bigger one. I did a little poking around on the Internet and found a tankless water heater that is a direct swap for the Suburban on Amazon. It runs about $600. It weighs a little less than half the weight of the Suburban, thus saving you an additional 24 lbs. [The Suburban cost almost $500.] https://www.amazon.com/Girard-2GWHAM-Demand-Tankless-Heater/dp/B019BWN8E2/ref=sr_1_24?crid=KZEQQ40ZYQX9&keywords=tankless+water+heater+for+rv+propane&qid=1549717924&s=gateway&sprefix=tankless+water+heater+for+rv%2Caps%2C201&sr=8-24 Tankless water heaters are activated by flow, so you have to run it long enough to get the flow hot. I'm using one right now every day for a shower and it takes quite a bit of water passing through the system before the water from the heater gets hot enough to be useful. That amount will depend on the starting temperature of the water, the distance to the point of use, the flow rate, and the efficiency of the heat exchanger. So, you'd want to compare how much water you will use to get usable hot water from both the tankless and tank systems. My suspicion, based on using one every day here in Colombia, is that you'd use pretty close to a couple of quarts to a gallon before getting useable hot water. And if you take mariner's showers, you are going to have to reheat each time you turn the water off and on. [The amount of reheating depends on how long it's turned off and the ambient temperature of the fresh water in the tank.] In contrast, the tank gives you nearly instant hot water with each turning off and on, the delay being the distance from the tank to the shower and how fast the hot water in the line cools off. Given the limited tankage, both gray and fresh, and the higher level of water use for a tankless water heater, if you boondock, such a system may not be the best option. On the other hand, if you tend to stay in RV parks with full hookups and don’t have to worry about a limited supply of water and gray water tankage, then such a system could be ideal. So, the decision really depends on how you use your shower and sink, whether the extra use of water needed to get useable hot water is more efficient than lugging around an extra 65 lbs. of water and water heater for the tanked system. I'd be interested in your experience if you change out your unit for a tankless, so please let us know.
	Never leave footprints behind. Fred & Maria Kearney Sonoma 167RB Our Pod 172 2019 Ford F-150 4x4 2.7 EcoBoost