Tankless or Tank Decision time

[CLH]

This is for a new build, 800 s/f apartment, DW, Sink,Washer, tub/shower combination 30X60 tub, deep, and first floor is enclosed porch with DW and sink. In the apartment 2 people. My builder is suggesting tankless, I think because the plumber already put up the wall for it in the attic. Regardless, gas, vented to outside, attic foamed. This is what they suggested. Rinnai R75LSi gas. I did search the internet for reviews, knowing nothing about this type of water heater. They say it is unavailable which leads me to believe it might be discontinued, especially since most of what I could find was dated 2007-20012. The other choice is a tank. I would assume a 40 gal. would be fine. I am putting in a water softener. Oh, and this is in Houston, so ground water temp is not cold. Advice, is there a big cost difference for the units or installation. Is there a big delay waiting for hot water. Can you fill a deep tub, standard tub deep enough to really soak? Is this model a good option, I am worried if it is an older model that it might be or will be shortly discontinued for any repairs. I have never really had repairs on a tank water heater, just the occasional drain etc. Should I look at other brands/models or just go with a tank? Thanks in advance for sharing your advice. I have learned alot using this forum about water softeners and mine has served me well since 2010, new house is getting the same. Thanks again.

 

[CLH]

So does anyone know if this model is discontinued? Most reviews are not flattering, but I would rather hear from professionals that random online reviews.

 

[Sponsor]

 

[Stuff]

Discontinued. Not on Rinnai's web site https://www.rinnai.us/tankless-water-heater

Tank normally recommended.

Tankless are normally more expensive to buy and more expensive to install. They do save on gas and last much longer. Slight delay in getting hot water but is "endless" that few need. Depending on your water you might need to descale so make sure piping/valves are installed to assist.

 

[CLH]

Discontinued. Not on Rinnai's web site https://www.rinnai.us/tankless-water-heater

Tank normally recommended.

Tankless are normally more expensive to buy and more expensive to install. They do save on gas and last much longer. Slight delay in getting hot water but is "endless" that few need. Depending on your water you might need to descale so make sure piping/valves are installed to assist.

Thanks for the reply. Are you saying you recommend a tank? I used this R75LSi gas in the search link you supplied, it says no results. I cannot this specific unit.

 

[Bannerman]

In addition to higher efficiency with a condensing tankless unit, a large benefit of tankless is the small amount of space required. With a small residence, every bit of space can be important so the ability to hang a tankless heater on a wall in an out of the way location can free-up premium floor space that might be otherwise used for a heavy and large tank-type heater.

As a tankless unit will fire immediately when water is drawn, the wait time for hot water to arrive at a faucet will be not much different than using a tank-type heater. Some tankless models include a built-in small buffer tank and circulation pump so heated water can be circulated within a plumbing loop to reduce the time needed for heated water to arrive at remote faucets.

Mineral Scaling that can occur in a tankless, is likely to also accumulate within a tank-type heater. Use of a proper water softener will be beneficial to reduce or eliminate scaling within either type of water heater.

Tankless models are often updated with new capabilities and features so it is not unusual for models to be discontinued. Suggest buying through company authorized dealers who will stand behind and service what they sell as opposed to shopping on A__n or other online sources.

There are other quality brands to consider and compare such as Navien, Rheem, Ecotemp etc.

 

[CLH]

Thanks Bannerman, I am not selecting this water heater, my builder is. I asked him for the model number so I could make an informed decision. The Rinnai website does not allow you to search a specific model, I have to call and talk to a dealer. I was looking for information on this model. All the information I can find is online, and it is not longer available, and the reviews are lukewarm to negative, and I know complainers like to post. The only information I have been given is R75LSi gas. I am getting a water softener and will have the water heater maintained. I just want information on this model. I have used this forum to get a water softener and now have a system that works put in by a plumber that installs the Fleck or Clack controllers and not the Rainsoft etc. So I have gained so much from reading this forum. Now I need info on a specific rankles R75LSi gas, hopefully I can learn enough to make a decision

 

[Reach4]

https://media.rinnai.us/salsify_ass...d57-6dd96d0a4d94/Builder R75LSi (VB) Spec.pdf

https://media.rinnai.us/salsify_ass.../U287-079(00) R50LSi, R75LSi, R94LSi (UC).pdf

 

[Jbrk]

I have an htp crossover wall unit. I like it so far. If I were to do it again, I'd probably go with a cheaper tankless unit and install larger buffer tank than what the crossover internal tank has.

So with that I suggest tankless with a buffer tank.
Or tanked with a higher btu rating and variable output. The latter being more expansive than a regular tank unit but less complicated install than the former.

Ps, I'm not a plumber, I just like plumbing.

 

[Bannerman]

The Rinnai website does not allow you to search a specific model,

I anticipate the Rinnai website only lists current models, not models that have been discontinued.

I am not selecting this water heater, my builder is.

I appreciate that you trust your builder enough to allow him to choose many of the products and materials for your project. Perhaps your builder has utilized that Rinnai model previously for other projects so he is planning to use the same model for your project without knowing it is discontinued.

Another possible scenario could be, your builder found a supplier that purchased clearout stock of that discontinued model which are now being offering at a discounted price. On clearout stock, there can be issues regarding warranty as clearout products are often sold without any manufacturer warranty so any warranty specified will usually be limited short term, as offered by the wholesale supplier.

Ultimately, your builder works for you so your preferences and decisions will take priority.

 

[Reach4]

I appreciate that you trust your builder enough to allow him to choose many of the products and materials for your project. Perhaps your builder has utilized that Rinnai model previously for other projects so he is planning to use the same model for your project without knowing it is discontinued.

Could it be that is a current builder grade WH version that they don't list in their main website?

 

[Jadnashua]

The incoming water temperature is a big determining factor when thinking about using a tankless as is the actual volume you need at any one time. WIth a tank, the entire contents is the same temperature when you start (well, close!). With a tankless, it all depends on the burner size and the volume you are asking it to deliver. So, two different scenarios...say you love to take a long hot soak in a big tub. A tankless might be useful, but might not as well since the volume requested at the tub valve may exceed the ability of the tankless to heat it as it goes by. Think waving your hand over a candle flame...move slowly, you might burn yourself...move quickly (like when drawing lots of water), and you may hardly notice it. Same thing with a tankless system. Occasionally need to use a hot cycle on your washing machine to sanitize something? You may not get it very hot with a tankless system, regardless of how much you need to fill the thing.

They generally do cost more to buy and are more complicated to install. On a new construction, they should be able to ensure you have enough gas supply and the piping is sufficient. On a retrofit, that may not be the case. The burner in a typical tankless is about 200K BTU...that's probably 5x more than a heating system may need. A typical stove uses maybe 40-60K, so adding a 200K load to the supply needs some advance planning. MOst places don't have a demand charge (a charge based on your peak usage), but some do. A tankless could trigger a higher base rate in areas that use that type of pricing compared to the standby losses in a tank. Some tankless systems don't allow hot water recirculation, so probably not an issue in a small place like you're planning, but that could mean a long wait to get hot water at the furthest location. It does take a moment for the flow sensor to detect demand and then the burner assembly to come up to speed. Not an issue with a tank, since it's already hot. Some dishwashers and washing machines tend to pulse water during part of their cycle...the tankless system will often end up just starting to turn on when the 'pulse' turns off, and may not provide much hot/warm water to those devices. Turning on/off is often when things fail. Lots of extra cycles may mean shorter life. A tank tends to run longer, and is simpler...any decent plumber can replace or repair one with parts on their truck most of the time, weekday or weekend.

Having a continuous source of hot water might tempt you into taking longer showers, so the savings overall may not be huge if they exist. NOt every plumber is capable of troubleshooting a tankless system, nor are you likely to be able to find parts on the weekend or get it fixed then, either. So, lots of things to think about.

Even with soft water, you'll likely need to descale the thing. Not as often, but still. By the time a tank typically may benefit from that, it's time to replace it, so most people never deal with it.

 

[Bannerman]

Could it be that is a current builder-grade WH version that they don't list in their main website?

While possible that particular Rinnai model is intended for a specific restricted market, since the OP indicates it is listed on A---n, that seems to suggest it was a model available to the general public.

Usually, 'Builder Grade' will be less expensive than that manufacturer's other similar products. As a less expensive line, the quality of components, features or warranty terms may be less than a more premium line, but not always.

Even if that specific model remains current and available to only builders, CLH is paying the costs and will be dealing with that choice long term. As CLH has taken it upon himself to research that model but is not having success on the Rinnai website, he should be requiring his builder to supply relevant product information and specifications so he may compare to other similar products before deciding which type, brand and model he will pay to have installed.

 

[CLH]

https://media.rinnai.us/salsify_asset/s-5d96464f-b07f-4ed9-ad57-6dd96d0a4d94/Builder R75LSi (VB) Spec.pdf

https://media.rinnai.us/salsify_asset/s-e516b648-312a-4776-8259-9fa5810ca588/U287-079(00) R50LSi, R75LSi, R94LSi (UC).pdf

Bless your heart, thank you.

 

[CLH]

I have an htp crossover wall unit. I like it so far. If I were to do it again, I'd probably go with a cheaper tankless unit and install larger buffer tank than what the crossover internal tank has.

So with that I suggest tankless with a buffer tank.
Or tanked with a higher btu rating and variable output. The latter being more expansive than a regular tank unit but less complicated install than the former.

Ps, I'm not a plumber, I just like plumbing.

Thanks for the information, I do not know what a buffer tank is and what it's purpose is.

 

[CLH]

I anticipate the Rinnai website only lists current models, not models that have been discontinued.


I appreciate that you trust your builder enough to allow him to choose many of the products and materials for your project. Perhaps your builder has utilized that Rinnai model previously for other projects so he is planning to use the same model for your project without knowing it is discontinued.

Another possible scenario could be, your builder found a supplier that purchased clearout stock of that discontinued model which are now being offering at a discounted price. On clearout stock, there can be issues regarding warranty as clearout products are often sold without any manufacturer warranty so any warranty specified will usually be limited short term, as offered by the wholesale supplier.

Ultimately, your builder works for you so your preferences and decisions will take priority.

I had a previous problem with a seriously oversized HVAC. So I am, and was asking for all model numbers, specs. This is a custom build in highly desirable area on a big lot, and yes the builder works for me and it's my money. However, I don't know the technical stuff, just enough to know I need to know more to make an informed decision. Background, senior citizen recently widowed, I really would like to be taken seriously by all the people I am paying, sometimes I am afraid I have not been. That's why some of my questions are more basic, I don't know what to ask. I sincerely thank everyone here, I learn so much, not all of it sticks, unfortunately.

 

[CLH]

Could it be that is a current builder grade WH version that they don't list in their main website?

I don't know, I guess I will have to specifically ask 1. is this discontinues, 2. is this regular builder grade so not on the website. I did get the info and specs that you listed in your post above.

 

[CLH]

The incoming water temperature is a big determining factor when thinking about using a tankless as is the actual volume you need at any one time. WIth a tank, the entire contents is the same temperature when you start (well, close!). With a tankless, it all depends on the burner size and the volume you are asking it to deliver. So, two different scenarios...say you love to take a long hot soak in a big tub. A tankless might be useful, but might not as well since the volume requested at the tub valve may exceed the ability of the tankless to heat it as it goes by. Think waving your hand over a candle flame...move slowly, you might burn yourself...move quickly (like when drawing lots of water), and you may hardly notice it. Same thing with a tankless system. Occasionally need to use a hot cycle on your washing machine to sanitize something? You may not get it very hot with a tankless system, regardless of how much you need to fill the thing.

They generally do cost more to buy and are more complicated to install. On a new construction, they should be able to ensure you have enough gas supply and the piping is sufficient. On a retrofit, that may not be the case. The burner in a typical tankless is about 200K BTU...that's probably 5x more than a heating system may need. A typical stove uses maybe 40-60K, so adding a 200K load to the supply needs some advance planning. MOst places don't have a demand charge (a charge based on your peak usage), but some do. A tankless could trigger a higher base rate in areas that use that type of pricing compared to the standby losses in a tank. Some tankless systems don't allow hot water recirculation, so probably not an issue in a small place like you're planning, but that could mean a long wait to get hot water at the furthest location. It does take a moment for the flow sensor to detect demand and then the burner assembly to come up to speed. Not an issue with a tank, since it's already hot. Some dishwashers and washing machines tend to pulse water during part of their cycle...the tankless system will often end up just starting to turn on when the 'pulse' turns off, and may not provide much hot/warm water to those devices. Turning on/off is often when things fail. Lots of extra cycles may mean shorter life. A tank tends to run longer, and is simpler...any decent plumber can replace or repair one with parts on their truck most of the time, weekday or weekend.

Having a continuous source of hot water might tempt you into taking longer showers, so the savings overall may not be huge if they exist. NOt every plumber is capable of troubleshooting a tankless system, nor are you likely to be able to find parts on the weekend or get it fixed then, either. So, lots of things to think about.

Even with soft water, you'll likely need to descale the thing. Not as often, but still. By the time a tank typically may benefit from that, it's time to replace it, so most people never deal with it.

I am in Houston, the ground water temp in the summer out of my kitchen sink is well over 80, just checked it's 80 degrees today, so in the winter about 55 give or take. They put in all new gas lines to the property, to supply house, and pool heater.. This is serving 2 dishwasher, 2 kitchen sinks, on bathroom sink, and 1 tub shower and temporarily washing machine, which moves to house when addition is completed. The biggest single use will be taking baths, standard 30X60 tub/shower, not a whirlpool but deep enough to soak.

 

[CLH]

Ok I got some more information. so the first model on the left.
RL75IN Tankless Water Heater | Rinnai

 

[CLH]

I was concerned that 4/7 gals./min. would be enough. The tub spec’d is 15” water depth, 57+ gallons. It is a regular 30X60 tub but deep enough to soak in.

 

[Bannerman]

That tankless unit is not a condensing model so the gas efficiency is rated at 81% as opposed to 90+%. Probably not a significant issue as your Texas incoming water temp maybe 75 degrees + so the temp rise and gas usage will not be as significant compared to 45 - 50 degree incoming.

It appears the 4.7 gpm flow rate is based on a 63-degree rise (in 57 - out 120) but as your water is likely much warmer, the supported flow rate will be higher, closer to the maximum 7.5 gpm that can flow through the heater while maintaining 120 F output.

Filling a tub for immediate use will not typically utilize 100% hot water, but will use a blend of hot and cold. The tub fill rate will likely be closer to the flow rate supported by the home's plumbing and tub faucet.