Tankless Water heaters, yeah or nah?

[ripperd]

A natural gas water neater will NOT operate without electricity. The Feds banned standing pilot water heaters 2 years ago.

Tommy

Thats not true. I just picked up a natural draft water heater to replace a failed one within the last year. Standing pilot and all. They are still available for sale on all the big box store websites. I do think code dictates power vented higher efficiency water heaters in new construction though.

edit: https://www.menards.com/main/plumbi...l-gas-water-heater/p-1444452228745-c-8690.htm

 

[Showkey]

Also power and natural draft vent are often the same efficiency. There are high efficiency power draftunits but all are.

 

[Jeepster04]

Forgive me if this has been discussed, I dont always have time to read every comment.

Whats everyone's opinion of the hybrid tankless water heaters? I guess it has a small 1 gal tank in it that stores hot water. Eliminates cold sandwiches and the time that it tanks the burner to kick on.

My opinion on tank water heaters as a whole, I would consider one for a new install but swapping my current gas water heater to a tankless would not be beneficial IMHO. It would also make me very late for work as I normally just shower till Im out of hot water. Tanks around 15 minutes for me to deplete my 40gal water heater with my 5GPM shower head.

 

[Gila Monster]

A lot of people are saying how much they like their tankless, but I have never had an issue with my tank unit either. I never run out of hot water, it's just something you don't even think about.

And my monthly bill is like $15 for natural gas. Any cost savings would be trivial to switch to tankless. Plus the units themselves are just a lot cheaper. At least in my application, it would be something like 20 year plus to break even. And there's no upsizing of gas lines to accommodate it or descaling the unit.

I guess I can see the value if you are on something like propane or you are really limited on space.

 

[Git]

I tend to agree. I have been watching this thread because my water heater is about 13 years old now, (still works great) but I like to have my ducks lined up when it does fail

We have natural gas and the bill is like $20 a month... Not a very big demand for a lot of hot water at once. I am all for saving money, but I just do not see the return by going tankless. The one advantage I see would be that I could gain some storage space where the traditional water heater is now, but that is about.

When a tankless fires up - is it noticeably loud?

 

[bggrnchvy]

I put a tankless unit in to replace my older tanked unit.

The biggest two benefits I saw for my application were getting the space back in the garage, as I mounted my tankless unit outside (moderate climate) and not storing 50 gallons of water in my garage waiting for it to leak in 10 years.

If I had to pay somebody to do the gas and electrical modifications to make it fit though, I don't believe I would have done it, the cost/benefit wouldn't have panned out.

I haven't had any issues out of my Rheem, and I've had about a half dozen Nortiz units put on CIP stations skids at work and they have worked without issue for years.

 

[Showkey]

You poor guys in CA have no basements ..............us guys in the midwest 2000-4000 sqft basements for all the HVAC stuff, water heaters and storage

 

[fsae0607]

I'm also thinking of going tankless. Our water heater is in our laundry room in its own closet and there's no plumbing for the T&P valve and drain pan. I replaced our water heater last year on Father's Day (yay me) with a Rheem unit from home crapo.

I want tankless so we can free up the closet space so the wife can have her pantry (and excess booze storage for me) plus not having 40 gallons of water ready to destroy our kitchen floor.

Only issue would be the plumbing re-route, since I'd like it installed outside. Our water heater is next to our side door and the gas meter is right there. Wouldn't take much.

 

[joseywales]

The feedback I'm getting is that the additional pressure line is an unnecessary up-charge, in most cases. I know most utility companies want to calculate, based on 100% demand. So the gas range, dryer, heater, water heater, etc. all running at the same time. That's just not realistic and unless the town insists on it, the larger line is just a profit stream.

 

[Jackfre]

In SW PA I find that tankless gas works fine in the summer but in the winter when groundwater temps dip there are problems. Showers are OK but wide open like filling the bathtub or the washing machine just gives lukewarm water.

Why a larger line? I had my pressure upped for free. Love my tankless.

Bathtubs can be a problem with tankless, depending upon the water fill line size of the tub faucet and the tub size. If you have a 3/4" supply or one of those "waterfall" type spouts you will not get the same "visual affect" with a tankless as a tank, but the tankless will fill the tub. The 3/4" fill can supply up to 10-12 gpm. The tankless will regulate the flow to guarantee temperature is at the set point on the unit. That is usually 120*.
I will use Rinnai as an example as I've worked with them since '91, use them in my homes and am a technical trainer for them. I will not use the 199,000btu units as that is much larger than what the OP requires. The RUC-80i is a .95 EF unit with a max input of 152,000 btu. When in the winter your supply temps drop, and that is dependent upon where your water originates, the units output will decline. (In my MA home I usually saw a 5-10* drop for about 3 month of the year. With my current well the temps are consistent year round.) Specifically, the RUC80i at at 50, 60 or 70* temp rise will produce 5.9, 5.0, & 4.2 gpm respectively...all day long. If you sit in a bathtub over 105* you are no longer bathing but par-boiling, so that is the max temp.
Tankless water heaters, at least the good ones, are designed to guarantee temp at the expense of pressure. In this case if you tried to fill a tub with that 3/4" supply the unit would reduce the flow to guarantee temperature and with that RUC80i you would likely fill the tub at around 5 gpm. I have a 40 gal clawfoot tub and it takes about 5-8 minutes to fill the tub. I'm not suffering.
The number one mistake in tankless installations is inadequate gas line sizing. You may not need to increase the size of the gas line IF THE EXISTING SYSTEM CAN SUPPORT IT, but eyes open on this. You can pipe them with 1/2" pipe but the system has to be spot on to make them work. 3/4 gives more margin for error.
Location matters. Don't put it out in the N 40. Try to stay close to the primary point of use. The RUC80 can vent with PVC pipe or with the proprietary concentric poly-propylene 5" pipe. If you are on an outside wall, use the concentric pipe. If in the middle of the house the pvc may be a better option. The concentric is one 5" hole in the wall. The PVC has two 3".
In the past recirc systems for tankless have been a problem. Today, you can use Rinnai's new wireless module to operator the recirc system. Install a wireless push button up under the kitchen cabinet and the wireless motion sensor in the M Bath. You can control the water heater on your mobile device and also receive error codes if the unit is not happy. It is a slick system and is backwards compatible to all Luxury and Ultra series Rinnai's made since '06. V series does not have the Circ-logic so no go there.
For a couple days, pay attention to exactly how many minutes a day you actually have a hot tap open. I think you will be surprised at how seldom out of 24 hrs you are drawing hot water. I put in my first unit in our home when my girls were middle school. My gas bill dropped by 40%. It should have been greater savings, but once people know that they are not going to run out of hot water they tend to linger a bit more. Better comfort in other words. No one ever ran out of hot water. Years later a classmate friend of my daughters was getting married. We had a house full of kids. About 18-20 people showered and we never ran out of hot water. Now in our new home it is just the two of us but hot water is never an issue.
Hire a good guy who has attended the factory trainings. Get off on the right foot.

 

[Dkramer]

I replaced the electric tank type water heater in my last house, over 10 years ago, and never regretted it. It did not require electricity, nor did it have a standing pilot. It had a small generator in the water line that created the current needed for the spark module when you turned on the water. My electricity bill dropped more than my gas bill went up. And with five of us, three daughters, my wife and I, we never ran out of hot water. The unit was made by Bosch. It vented with metal flue, not PVC like most of the new ones, but was still very efficient. I don't know if they make them anymore, but it was the best investment I could have made. If I lived now where I could get natural gas, I would do it again. Propane is too expensive and fluctuates to much around here for me to go that route, and my three daughters have long moved out anyway.

 

[yeldogt]

The feedback I'm getting is that the additional pressure line is an unnecessary up-charge, in most cases. I know most utility companies want to calculate, based on 100% demand. So the gas range, dryer, heater, water heater, etc. all running at the same time. That's just not realistic and unless the town insists on it, the larger line is just a profit stream.

Guess it depends on how short -- your furnace is not going to like the loss of pressure when it needs it.

 

[yeldogt]

Bathtubs can be a problem with tankless, depending upon the water fill line size of the tub faucet and the tub size. If you have a 3/4" supply or one of those "waterfall" type spouts you will not get the same "visual affect" with a tankless as a tank, but the tankless will fill the tub. The 3/4" fill can supply up to 10-12 gpm. The tankless will regulate the flow to guarantee temperature is at the set point on the unit. That is usually 120*.
I will use Rinnai as an example as I've worked with them since '91, use them in my homes and am a technical trainer for them. I will not use the 199,000btu units as that is much larger than what the OP requires. The RUC-80i is a .95 EF unit with a max input of 152,000 btu. When in the winter your supply temps drop, and that is dependent upon where your water originates, the units output will decline. (In my MA home I usually saw a 5-10* drop for about 3 month of the year. With my current well the temps are consistent year round.) Specifically, the RUC80i at at 50, 60 or 70* temp rise will produce 5.9, 5.0, & 4.2 gpm respectively...all day long. If you sit in a bathtub over 105* you are no longer bathing but par-boiling, so that is the max temp.
Tankless water heaters, at least the good ones, are designed to guarantee temp at the expense of pressure. In this case if you tried to fill a tub with that 3/4" supply the unit would reduce the flow to guarantee temperature and with that RUC80i you would likely fill the tub at around 5 gpm. I have a 40 gal clawfoot tub and it takes about 5-8 minutes to fill the tub. I'm not suffering.
The number one mistake in tankless installations is inadequate gas line sizing. You may not need to increase the size of the gas line IF THE EXISTING SYSTEM CAN SUPPORT IT, but eyes open on this. You can pipe them with 1/2" pipe but the system has to be spot on to make them work. 3/4 gives more margin for error.
Location matters. Don't put it out in the N 40. Try to stay close to the primary point of use. The RUC80 can vent with PVC pipe or with the proprietary concentric poly-propylene 5" pipe. If you are on an outside wall, use the concentric pipe. If in the middle of the house the pvc may be a better option. The concentric is one 5" hole in the wall. The PVC has two 3".
In the past recirc systems for tankless have been a problem. Today, you can use Rinnai's new wireless module to operator the recirc system. Install a wireless push button up under the kitchen cabinet and the wireless motion sensor in the M Bath. You can control the water heater on your mobile device and also receive error codes if the unit is not happy. It is a slick system and is backwards compatible to all Luxury and Ultra series Rinnai's made since '06. V series does not have the Circ-logic so no go there.
For a couple days, pay attention to exactly how many minutes a day you actually have a hot tap open. I think you will be surprised at how seldom out of 24 hrs you are drawing hot water. I put in my first unit in our home when my girls were middle school. My gas bill dropped by 40%. It should have been greater savings, but once people know that they are not going to run out of hot water they tend to linger a bit more. Better comfort in other words. No one ever ran out of hot water. Years later a classmate friend of my daughters was getting married. We had a house full of kids. About 18-20 people showered and we never ran out of hot water. Now in our new home it is just the two of us but hot water is never an issue.
Hire a good guy who has attended the factory trainings. Get off on the right foot.

Good explanation ... the recirculation sort of defeats the idea .. but, having the ability for the work around helps in some applications.

It's like my good friend the eye surgeon who's never had Lasik -- too risky for someone in his position. My plumber and builder just looked at me today when I mentioned this thread.

 

[shooon]

I went with a rheem tankless unit and am quite happy with it. Has been running without issue for 4 - 5 years now. I also opted to use the same model unit for my in floor heat setup in the garage.
Having two identical units is nice so I can order a single spare flame sensor and ignitor and they are compatible with both units. Or if my heater in the house craters and I don't have parts I can borrow from the in floor setup to get me by.

Something to point out in case people are wondering-
Yes the tankless units have a crazy high btu rating, however it's extremely rare you will have the unit putting out that much.

The gas valve is modulating, meaning it only lights a portion of the burner and adjusts manifold gas pressure as needed. If I run a single shower in my house I'm running a partial burner with low manifold output. I have to crank every hot water fixture in my house open to get the whole burner to fire, and even when it does it fires the whole burner at low output.

The main factors that will affect how many BTU's the unit uses is the Delta T of the inlet to outlet water temp, as well as the water flow rate. As the two of those variables increase, the unit will need to put out more to maintain the outlet temp.

An added bonus of the tankless unit if you enjoy long showers, is that you can set your hot water tap up once and the temperature stays constant throughout. With the hot water tank you usually find yourself gradually cranking the hot water up more and more.. not a huge deal but it is pretty nice not to have to mess with it as frequently.

With the space I saved by removing my water tank, I was able to install a water softener and filter setup.

 

[Jackfre]

Yeltdog, the recirc is a necessary evil in many cases and no, it does not defeat the purpose. It prevents water waste and here in the west, although we had a heavy rain season last year, you cannot forget the 5 previous years of intense drought. Waiting for hot water wastes water. The trick has been to develop a system which maximizes the comfort without putting excessive wear on the unit. For example. Back east I had a customer who installed his own circ. on his tankless water heater plugged it into an outlet and let it run 24/7. Now, a tankless will fire any time it sees flow and the delta T is great enough to be able to fire at its minimum. 6 mos later I get a call from this guy. "My water heater is broken." Rinnai's don't break in 6 mos. Engineering wanted the unit back for testing so we replaced it. Engineering came back and said the unit had fired over 88,000 times and had flow through it equal to about 45 years of use. CA has a program called Title 24 and much of it is energy codes and building regulations. To get points toward T 24, no recirc system which is time or temp controlled gets points. Why, energy waste. Goodbye timers and A-stats. "On demand" recirc is where it is at and the wireless push buttons and motion sensors are the best compromise on comfort, energy and water conservation. It is also the very best system control for tankless water heaters. Over the many years I have been in the pipe trades, in one way or another, I've seen a lot of poorly controlled recirc. systems that consume more energy in heat loss off the systems than the actual energy required to heat the water being used.
The other advantages of the wireless are that you can register your warranty simply and always know what that warranties status is. I can't tell you how many contractor/homeowner discussions I've had about "I think it is still covered under the warranty?" It is always a pita. Not with the wireless, it will always know model, ser. no, and warranty status. If you enable the installing contractor to see the unit, he will receive error codes and be able to affect a "one call" repair as he will know the parts usually necessary to address that particular error code. I like being able to set the output temp on the water heater. If I am filling the tub for me, I will set the output temp at 102 and run hot only and it will deliver that temp water. When I wash the dog I set it at 98. Standard set point is 120 on mine in winter and 115 in summer.

 

[yeldogt]

Yeltdog, the recirc is a necessary evil in many cases and no, it does not defeat the purpose. It prevents water waste and here in the west, although we had a heavy rain season last year, you cannot forget the 5 previous years of intense drought. Waiting for hot water wastes water. The trick has been to develop a system which maximizes the comfort without putting excessive wear on the unit. For example. Back east I had a customer who installed his own circ. on his tankless water heater plugged it into an outlet and let it run 24/7. Now, a tankless will fire any time it sees flow and the delta T is great enough to be able to fire at its minimum. 6 mos later I get a call from this guy. "My water heater is broken." Rinnai's don't break in 6 mos. Engineering wanted the unit back for testing so we replaced it. Engineering came back and said the unit had fired over 88,000 times and had flow through it equal to about 45 years of use. CA has a program called Title 24 and much of it is energy codes and building regulations. To get points toward T 24, no recirc system which is time or temp controlled gets points. Why, energy waste. Goodbye timers and A-stats. "On demand" recirc is where it is at and the wireless push buttons and motion sensors are the best compromise on comfort, energy and water conservation. It is also the very best system control for tankless water heaters. Over the many years I have been in the pipe trades, in one way or another, I've seen a lot of poorly controlled recirc. systems that consume more energy in heat loss off the systems than the actual energy required to heat the water being used.
The other advantages of the wireless are that you can register your warranty simply and always know what that warranties status is. I can't tell you how many contractor/homeowner discussions I've had about "I think it is still covered under the warranty?" It is always a pita. Not with the wireless, it will always know model, ser. no, and warranty status. If you enable the installing contractor to see the unit, he will receive error codes and be able to affect a "one call" repair as he will know the parts usually necessary to address that particular error code. I like being able to set the output temp on the water heater. If I am filling the tub for me, I will set the output temp at 102 and run hot only and it will deliver that temp water. When I wash the dog I set it at 98. Standard set point is 120 on mine in winter and 115 in summer.

Yes, the recirculation can be a big waste ... my first Buderus radiant floor /panel/indirect setup 25 years ago had two pumps just to keep the water hot at all the far flung faucets. I learned a lot doing that house.

Tankless has it's place in the mix of possibilities -- Just don't think it's a great choice for small households or for general retrofits -- especially when NG is available. Many of the wants on this thread talk about things other than heating water -- space mostly. I'm a boiler/indirect guy for most of my projects -- being in the mid atlantic .. we need heat.

I'm doing my first project with PEX and home run piping -- will be interesting to see how this works without recirculation. All the runs are short .. I was going to use the Viessmann floor unit with the small tank -- sticking with Buderus and 32g indirect. I could have used a combi -- but, again the standby loss is so small with the better tanks ...even with propane I'm not fighting with the on demand .

 

[LS6 Tommy]

Thats not true. I just picked up a natural draft water heater to replace a failed one within the last year. Standing pilot and all. They are still available for sale on all the big box store websites. I do think code dictates power vented higher efficiency water heaters in new construction though.

edit: https://www.menards.com/main/plumbi...l-gas-water-heater/p-1444452228745-c-8690.htm

Yeah, you're right. I was thinking of new construction. I edited my post.

Tommy

 

[joseywales]

We went with the Navien NPE-180A- Natural gas tankless heater. It has comfort flow, so there's a buffered tank and pump, which stores a small amount of hot water at the ready.

Prior to the installation, first thing in the morning, I held my hand under our master bedroom faucet - longest run. I waited until I couldn't stand the hot water, 24 seconds.

After we installed the Navien, that same test took, well, it never go so hot I couldn't stand it, but the unit is set to 120 degrees.

After 38 seconds, the water was what I consider shower hot. It would probably take one minute to get to "can't stand it" hot. Not sure the comfort flow has a big impact and I didn't order it special, but the water out of the faucet right off is not cold, so it could be due to the comfort flow.

Mine was probably a bit more installed, because we moved the location of the heater, which required two runs (13 feet) for the exhaust. We also relocated the household softener. The old WH and the softener were in opposite corners of the basement, so we gained a lot of usable space.

I'm very happy with the unit and the space it saved.

Side note - I come to find that the Sloan Flushmate toilets that came with our house can launch my *** into orbit, since they have been recalled. Who knew??? I called the company and they are sending me repair kits for both toilets.

Turns out these high pressure toilets can't handle high pressure...wait, what? It's getting so a guy can't even **** in peace these days.

 

[yeldogt]

We went with the Navien NPE-180A- Natural gas tankless heater. It has comfort flow, so there's a buffered tank and pump, which stores a small amount of hot water at the ready.

Prior to the installation, first thing in the morning, I held my hand under our master bedroom faucet - longest run. I waited until I couldn't stand the hot water, 24 seconds.

After we installed the Navien, that same test took, well, it never go so hot I couldn't stand it, but the unit is set to 120 degrees.

After 38 seconds, the water was what I consider shower hot. It would probably take one minute to get to "can't stand it" hot. Not sure the comfort flow has a big impact and I didn't order it special, but the water out of the faucet right off is not cold, so it could be due to the comfort flow.

Mine was probably a bit more installed, because we moved the location of the heater, which required two runs (13 feet) for the exhaust. We also relocated the household softener. The old WH and the softener were in opposite corners of the basement, so we gained a lot of usable space.

I'm very happy with the unit and the space it saved.

Side note - I come to find that the Sloan Flushmate toilets that came with our house can launch my *** into orbit, since they have been recalled. Who knew??? I called the company and they are sending me repair kits for both toilets.

Turns out these high pressure toilets can't handle high pressure...wait, what? It's getting so a guy can't even **** in peace these days.

They call it a buffer tank .. but it's storing water at temp to deliver to the faucet. It's a small storage tank. I believe all the A models have the capacity -- you can turn it off I believe. I have no idea what this adds to the cost of operation.

they can still give you some fluctuation initially -- but it takes most of it out for short duration uses .. like washing hands.

 

[Rdan]

I installed a 50 Gal Condensing Gas water heater about 8 years ago AO Smith Vertex. It was about $1000 more, after energy rebates, it was close to the cost of a power vent Hot water gas heater. My bills now are only about $19.38 for a family of 5 in the summer, and that includes the surcharge of $12.76. So I get the benefits of a Hot water tank and the savings of a Instant Hot water heater. A side benefit you can hook up in floor radiant heat if you want. Dan

 

[6768rogues]

I see no reason to ever buy a tankless water heater. If you are concerned about running out of hot water, get a standard one with a faster recovery time. Even when our kids were at home we never ran low on hot water. The standard water heater worked well for us so I see no reason to buy one twice as expensive so that I am married to it and have to pay to get it fixed rather than throwing it out and buying another if it breaks.

 

[joseywales]

I see no reason to ever buy a tankless water heater....

I saw no reason to have a 50 gallon hot water heater in the middle of my finished basement. Maybe I could have put stools around it and used it as a pub table

When this house was built, some dope stood in my basement and thought, "how can I screw up each corner of this basement?" He executed his plan perfectly...

 

[pgray007]

I saw no reason to have a 50 gallon hot water heater in the middle of my finished basement. Maybe I could have put stools around it and used it as a pub table



When this house was built, some dope stood in my basement and thought, "how can I screw up each corner of this basement?" He executed his plan perfectly...

That was my concern as well, except we have no basements in the south, so you loose a corner of your garage to the giant tank!


Sent from my iPhone using Tapatalk

 

[joseywales]

Well, I considered nearly none of what folks had listed. We were remodeling the basement and mad a decision on the fly and although some of what you listed was presented to me, the only advantage I was staring at was the fact that we could relocate the water heater and the softener.

By removing the water tank, I gained 37.5 sqf of space - the use of that entire wall changed for the better. By relocating the softener and salt tank, I gained a shuffleboard table and air hockey table - I only need about 2 feet to make them fit comfortably and I got more than that back. The water heater and softener were placed in an alcove of wall, which was previously useless. We were going to make it a closet and did so, we just put the salt tank, softener, and tankless unit in there and hung some sliders.

My utility bill? I don't know. I added a gas heater to my pool as well. Folks told me it would drain my bank account. I actually also began running my filter 24/7 this year. Guess what, I hardly notice the increases and my wife and I have used the pool more this year, then in the past 7 years combined, no exaggeration. If my neighbors would maintain their overgrown trees, I would need a heater, but that's another thread.

Do I wait for hot water? Yes. So, I turn on the shower, then brush my teeth. By the time I'm done brushing, shower is good to go. A small modification in behavior and I have no regrets.

If either the tankless water heater or pool heater have cost me money, it hasn't been much and the upsides have been very rewarding.

Bottom line: look at the intangible benefits when making any decisions.

PS: I don't use chemicals in my pool. Only bleach. If we lose public water, I could simply stop adding bleach to the pool and within 24 hours have over 7,000 gallons of water that's healthier than most tap water!

 

[Trey T]

My monthly cost for NG is about $25 for non-winter (april - november). If I go with tankless to potentially save $10/mo, it would take me 2-3yrs to recover the initial cost difference ($500, assume DIY for 3bd/3ba).

I would say yes!!!

 

[u3b3rg33k]

I helped a friend do a new water heater. 5 bedroom house, water heater was located under the chimney instead of in the mechanical room.

replaced a leaking 40 gal tank with a rinnai RUC98in.
we cut in a 1" drop from the main line to the heater, downsized at the drip leg (manual calls for 3/4", but we wanted to make sure there wouldn't be supply issues). I read the manual, he read the quick install card of 'do it right or suffer' warnings. venting was fun.

his average gas bill is $9 lower than before, but they probably use more hot water, and it gets to faucets faster due to the heater being about 30' closer. he can also use his master suite jet tub for the first time in 15 years as the heater doesn't run out halfway through filling it.

the heater is behind a water softener, and hopefully he'll follow the PM schedule in the book - i warned him he won't be happy with it if he doesn't. so far - he loves it. saving money on gas is just a fringe benefit.

 

[OsoOC]

The cheapest method to heat and store water is still an old fashioned tank via LP or NG. But they can't always keep up with demand if not sized correctly. Tankless... on paper are great. In the real world plumbers love them as they do require maintenance. And if you have mineral heavy water, you will get to know your plumber by name if you don't do an annual flush to remove baked on minerals. If you price out a tankless, but sure to factor in the flush valves and access which is something you can do if willing. There are online videos showing how.

Some areas require a permit to swap a tank. Most likely if swapping to tankless... you will have to pull a permit. Venting is a key issue and some older B vents might not be able to handle the BTU output would might start a fire or put dangerous gas into your home.


Recently installed an electric hybrid. Not sure if it's worth the extra price and the effort as it needs space around it to function/breathe which makes it a tad harder to earthquake strap where required. Also... the fan makes NOISE. Not something to want to listen to, perhaps even in a garage. And it's electric. Not a cheap option in many cases but it doesn't require a vent.

 

[u3b3rg33k]

The cheapest method to heat and store water is still an old fashioned tank via LP or NG. But they can't always keep up with demand if not sized correctly. Tankless... on paper are great. In the real world plumbers love them as they do require maintenance. And if you have mineral heavy water, you will get to know your plumber by name if you don't do an annual flush to remove baked on minerals. If you price out a tankless, but sure to factor in the flush valves and access which is something you can do if willing. There are online videos showing how.

Some areas require a permit to swap a tank. Most likely if swapping to tankless... you will have to pull a permit. Venting is a key issue and some older B vents might not be able to handle the BTU output would might start a fire or put dangerous gas into your home.


Recently installed an electric hybrid. Not sure if it's worth the extra price and the effort as it needs space around it to function/breathe which makes it a tad harder to earthquake strap where required. Also... the fan makes NOISE. Not something to want to listen to, perhaps even in a garage. And it's electric. Not a cheap option in many cases but it doesn't require a vent.

i'm not sure how you come to that conclusion.

take an outdoor center I know with tons of cabins. if you had 50+ water heaters, would you be interested in paying the propane bill for the pilot light? call it 750btu/hr per heater @ 50 heaters = 37500BTU/hr 24/7 for the entire 8 month operating season? they weren't. they switched them all to rinnai. No issues after years of operation. the propane savings are significant.

It scales linearly. one heater or one hundred.

they have a salaried plumber who has better things to do than maintenance on water heaters.

 

[ripperd]

My monthly cost for NG is about $25 for non-winter (april - november). If I go with tankless to potentially save $10/mo, it would take me 2-3yrs to recover the initial cost difference ($500, assume DIY for 3bd/3ba).

Same, but its actually even less than that. For me, on a summer $25ish gas bill, only about $10 of that is actual natural gas usage. The rest are fixed basic fees just to have service. So the potential savings are more like $2/month. Practically no payback.

 

[Trey T]

Same, but its actually even less than that. For me, on a summer $25ish gas bill, only about $10 of that is actual natural gas usage. The rest are fixed basic fees just to have service. So the potential savings are more like $2/month. Practically no payback.

I retract my enthusiasm and have to concur with your more accurate evaluation. That would take 10+ years to recover the initial cost difference.

 

[Showkey]

I retract my enthusiasm and have to concur with your more accurate evaluation. That would take 10+ years to recover the initial cost difference.

Same, but its actually even less than that. For me, on a summer $25ish gas bill, only about $10 of that is actual natural gas usage. The rest are fixed basic fees just to have service. So the potential savings are more like $2/month. Practically no payback.

Agree.........my actual NAT gas cost for hot water is $6-9 per month witha tank.

Those that are paying $1500-$3000 for the tankless install will never ever see a payback.

 

[Stuart in MN]

By removing the water tank, I gained 37.5 sqf of space

That's one big water heater...six feet square?

 

[driftpin]

We installed a Rinnai during a whole-home remodel, 3 br/4 full baths, the garage has a full bath, which I like very-much. The install was a good move for us, l like the never-ending H20, and we switched to a Wolf stove at the same time, but didn't get a gas dryer for clothes. We plumbed a stub for a backyard grille, but haven't added that yet. There's a pool but we haven't added a heater for it, but perhaps one day. The gas bill is lower than out electric use would be so we're happy with the install. I got back the room the water heater used in the garage, but I still have memories of me swapping out the last electric water heater on a Thanksgiving with a house-full of people for the traditional dinner.

 

[Jackfre]

In SW PA I find that tankless gas works fine in the summer but in the winter when groundwater temps dip there are problems. Showers are OK but wide open like filling the bathtub or the washing machine just gives lukewarm water.

I will use Rinnai as I know them best having represented them in one way or another for 27 yrs. That since 4/1 is over and I have no affiliation with them any longer. I do love their products. I have an RL-75LP in my home. It will max at 180,000 btu input at 82%. At a 70* temp rise, so from 50-120* that unit will absolutely reliably deliver 4.3 gpm of 120* water. If your supply water drops 10* that RL-75 will deliver .4gpm less or 3.9gpm. If the water warms 10* to 60* supply the unit will deliver 4.7 gpm.
You should be able to find the specs on your unit and be able to see exactly what is going on with your water heater. You can read the gpm outlet to .1gpm and see the actual temp rise. The best tankless guarantee temp delivery at the expense of pressure. If your tub can deliver 10 gpm due to its piping, your tankless may...will...reduce the flow to guarantee delivery temp (see above). There may be another issue, depending upon the manufacturer of your unit. Whose is it?

 

[FastKat]

I just got one if these and can't wait to install it. 20 gallon tank + 50/100k BTU maintenance free gas heating system. You get the best of both worlds. It is a rebranded HTP unit.

http://westinghousewaterheating.com/residential-gas-floor-hybrid.html

 

[ddawg16]

It's pretty obvious....those who want a tankless will find a way to justify it.

 

[chrismenke]

It's pretty obvious....those who want a tankless will find a way to justify it.

Like, if I go to tankless and reclaim that space in the garage I can have a lathe? See...easy!

 

[Trey T]

Like, if I go to tankless and reclaim that space in the garage I can have a lathe? See...easy!

If it's in the garage or laundry room, $500 difference to claim an effective 2ftx2ft of space is justifiable.

 

[sleek98]

I replaced my tank LP heater at our lake house with an electric tankless. The first 18 months we owned it I replaced a few thermocouplers, the tank had to be drained every time we went down since the water would smell bad. Just wasnt worth the trouble. The electric rates are cheap and havent had an issue since.

I dont think I would put on in our main home though. I would like one of the point of use ones for the master tub, you cant get it but 50% full before running out of hot water.

 

[archy99]

They may not be the best solution for every use/need, but they definitely have their advantages (and disadvantages). I did a complete rebuild of my 1940's rambler, going from 1268 sf on one floor with all unfinished basement, to 2600 sf on two-floors plus most of the basement is now finished.

I originally had a single 60 gallon electric tank unit in the low end of the basement (floor sloped to drain). In the rebuild, I replaced that tank with two gas-fired Navien NPE-180a's. I located one of them in the mechanical room in the basement, as close to the kitchen loads as possible (about 20' of pipe to the sink and DW) and midway between the kitchen and the basement laundry, and the other on the upper floor, in a small closet adjacent to the upper laundry, and mid-way between the two showers on that floor.

There is a short wait for hot water to the fixtures, but it's tolerable, and minimized by having two units. To me, this is preferable to having a return loop system constantly flowing, and using energy when we aren't using water. I have had no temperature demand issues thus far, even with two showers going, a bathtub being filled, and the clothes washer running...all of them on the upper unit.

I did wire for, and will still be installing, an instant hot water source in the kitchen, so a cup of hot water doesn't require running the main tap for 30 seconds.