Tankless water heater

[jeremyboudrot]

Looking at a Rinnai. Anyone use any of these? With rebates, it ends up being cheaper than a standard heater. Was wondering approximate ROI time? Any major "cons" aside from startup cost?

TIA!

 

[KELLHAMMER]

I don't much about Rinnai. One plumber I work with, says it's his favorite. I have a Bosch that has worked flawlessly for 10 years. My old elec. tank type tookup valuable sf in my basment. So for space saving alone it was a no brainer. My tank type was capable of running out of hot water after a couple of showers and doing laundry. ROI is going to be based on energy used or lost during standby. Which for a tankless is zero. I have heard that well water can be problematic for a tankless.

 

[2012 LML]

I have a Rinnai at my home, and several different brands at my business'.

Here is what I tell everyone;

Forget about ROI. I don't know if I am saving money or not. I do know this, I have never, ever ran out of hot water. 3 shower's at a time, no problem.

The big thing to pay attention to is temperature rise. I am in S. Florida, so it doesn't make much to make water hot. I hav business' in Central PA. that run tankless Rinnai's and they won't service as many heads, because of the temperature rise.

 

[KELLHAMMER]

For my house I bought the biggest tankless Bosch sold, which is actually made by Tagaki. I have a 4 bedroom 3 full and 2 -1/2 baths. I am in Pa. Biggest issue is the delay in getting hot water to the fixture. In the winter, the bathroom furthest from heater can take 2 minutes to reach temperature. I consider it a small issue considering the positives

 

[1967marti]

Don't know about that brand but i got the aqua star brand.... Works great since 2004. Runs on my big 200 gal propane tank.

 

[jeremyboudrot]

One question guys. What happens when it stops working? Does it just stop making hot water? Obviously the 40Gallon tank could potentially spew water all over the basement. What happens in this instance?

 

[killerjeep]

Electric units **** if you have a house full. They cant keep up if you run more than one sink at a time. I have had them and if you live alone its great. If its for the garage its great. If you have a family of 5 and little kids they are not good. You have to think whats going on. We tried it here and dumped it. In Europ and South America where my family lives they have gas versions and depending on the size of the house they will have more than one. So the savings is not much after a while. Been dealing with them all my life and not impressed. Dumped a 86 gallon tank in our house now and can do what ever we want when we want.

 

[Randy in Maine]

I used a Rinnai for about 10 years (and my friend is still using it). Still works flawlessly and far better in the longterm than those that HD or Lowes sell. Saved me piles of cash over an electric one.

If the power goes out it it quits working, you just won't get any hot water.

If you are on a well, install a sediment filter before the heater. None of these heater like crud in there.

 

[PCO6]

We've had a Rinnai since May of 2009 and have no problems with it. Lots of hot water and it takes up a fraction of the space.

 

[2012 LML]

One question guys. What happens when it stops working? Does it just stop making hot water? Obviously the 40Gallon tank could potentially spew water all over the basement. What happens in this instance?

It would depend on what failed, but to simplify the answer, yes it would just stop making hot water.

My Rinnai Propane unit is on the outside wall, so if piping failed, no big deal (other than the lack of hot water).

 

[2012 LML]

Electric units **** if you have a house full. They cant keep up if you run more than one sink at a time. I have had them and if you live alone its great. If its for the garage its great. If you have a family of 5 and little kids they are not good. You have to think whats going on. We tried it here and dumped it. In Europ and South America where my family lives they have gas versions and depending on the size of the house they will have more than one. So the savings is not much after a while. Been dealing with them all my life and not impressed. Dumped a 86 gallon tank in our house now and can do what ever we want when we want.

Don't ever get the electric on demand, unless it's for a small condo (like 1 bedroom) or for an individual fixture, i.e. kitchen sink.

 

[jeremyboudrot]

Will be getting gas. Hot water still goes out with no power, I assume? Can anyone confirm.

Thanks again.

And yes, definitely a Rinnai, or higher end brand. The rebates and tax credits make it cheaper than a 40Gallon tank!

 

[rlb1953]

My Bosch tankless is coming out today. I have to say I'm not very impressed. Long story short, even if the "water heater" part of the machine is in good shape, all the other parts of the machine are very expensive, as is diagnosing the issue with the machine, and the labor to get it fixed. Intermittent issues are very frustrating, and parts availability goes south long before the "lifetime" of your machine does.

Here is my experience.

I bought the machine in 2004. From 2009 and on, getting consistent ignition has been a problem. I've had the plumbers come in to look at it several times, and they didn't have any suggestions on how to make the machine light. If the tap was getting cold water, you just had to turn off the water and turn it back on again, and hope it lit this time. By the end of 2010 I was just turning the tap on, run for 5 sec, then off and on again EVERY time I used a tap. Plumbers came in, said there was nothing they could do... it appeared to be working correctly, there was gas and spark... just didn't catch.

Then last year, the motherboard went. Availability was a problem. It was a 3 week wait for the part, and for the price of the one part, I could have bought a new (tank) water heater. The plumber suggested that it wasn't worth fixing, but I figured if I got another 8 years out of the machine, then it would be worth it.... The new motherboard seemed to have a hotter spark than the old, so for the first month it worked like new... after 3 months, the no-light condition was starting to appear again.

Just last Thursday I came downstairs to find it acting up. With NO taps on in the house it was lighting the pilot, running the pilot for 10 seconds, then turning it off, and then re-lighting the pilot. it went on for a couple minutes.. I turned off the machine, and turned it back on again. Seemed good until I turned on a tap. Then it came on normally, but the burners DIDN'T SHUT OFF when the tap was closed. I turned off the machine again. Tried it again... this time the exhaust fan worked constantly, but the machine quit working all together. I read the manual front to back, re-set the sensor switch that activates the machine, but it would never turn on again.

The machine was unplugged and I called the plumber. A new 40 gal tank is going in this morning.

 

[rlb1953]

Will be getting gas. Hot water still goes out with no power, I assume? Can anyone confirm.

Not any tankless I've ever seen. The computer and power-vent both need power.

 

[davidlee]

I have 2 Rinnai tankless one upstairs and one for downstairs and I love them. They have been in for about 5 years with no problems. I don't think they give us any ROI since we now all seem to take longer showers. I will not switch back to tank type.

 

[jlckmj]

I have a Rinnai and so far (10 months) it has been great for the wife and I.

I have no idea of the ROI we re-did the whole house and have nothing to compare it to.

Jim

 

[2012 LML]

Will be getting gas. Hot water still goes out with no power, I assume? Can anyone confirm.

Thanks again.

And yes, definitely a Rinnai, or higher end brand. The rebates and tax credits make it cheaper than a 40Gallon tank!

No power, no spark, no hot water.

If you have or plan on putting in a whole house generator, the benefit is less demand for electric, smaller generator.

 

[Charles (in GA)]

Will be getting gas. Hot water still goes out with no power, I assume? Can anyone confirm.

Thanks again.

And yes, definitely a Rinnai, or higher end brand. The rebates and tax credits make it cheaper than a 40Gallon tank!

Yes, the gas tankless units DO NOT work if the power is off, as all of the controls are electric. Electric gas valve, temp measuring, flow switch, etc.

I tend to use hot water for everything I do. I am always reaching for the hot handle when turning on the faucet. My kitchen sink is a ways from the water heater and if I don't run the water regular, I have to contend with a slug of cold water first then warm/hot. Instead, I just run the hot water. With a tankless unit, especially gas, you cannot do this. You have to think about what you are going to use water for "I'm going to run a dishpan full for washing dishes" or "I'm going to leave it running while I rinse off dishes" vs "I just need to rinse my hands off" or "I just need a small pan of water to boil eggs/spaghetti" in both cases you will be forced to use cold water or put wear and tear on the heater unit for a couple of seconds of use.

If you are one to wash hands often, turn water on and off often and for very short periods of time, then you will not benefit from a tankless as you have to turn on the faucet and let it fire off, begin heating and for the warm water to reach you. I often do not run the hot water than long and long ago figured out that would be a waste.

A friend of mine had her old gas tank type replaced in late 2003 or 2004 (I'm not sure exactly, the heater was made 09/2003) and she used it as it should be, running water infrequently but in long spells so it could heat up. This was her nature to not "waste" water by using short spurts of water. The unit she installed was a Japanese made Noritz (gas) and it was "professionally" installed by a authorized installer, yet in June of 2005 it began to leak internally.

Noritz baulked at warranty claiming it had be improperly installed, as the old thru the roof vent had been used and you have to vent horizontally to prevent carbon and corrosion flakes from the vent pipe from falling back into the unit. Reality was, the leak was outside the fire box, in the bends in the tubes. When you bend tubing the outside radius of the bend is stretched and this weakens and thins the metal. A pin hole leak formed in the tube in a bend. They finally warrantied it providing she proved they installed a new horizontal thru the wall vent system.

Personally I think you would be better off (if using electric for heating water) by going to a Marathon tank unit. They claim a 5° or less heat loss in 24 hrs vs 15° or so for a regular tank type. No metal tank to rust or corrode and basically will last a lifetime.

My next water heater will be a Marathon. My current heater is just a month past ten years old, so it will probably get replaced in the next couple or three years.

Charles

 

[tomroblee]

I bought a new (to me) house with a Rinnai tankless heater. I've had not issues with it.

If you are replacing a tank type heater, there are two things to consider. The tankless water heater will use a lot more gas when it is running. I believe that the tag on my heater says that it is rated at 180,000 Btu compared to about 40,000 Btu for a standard 40 gallong tank type heater. Before you buy, you should check to see that you have an adequate gas supply. The second issue is that a tankless water heater will lime up much faster than a tank type heater. This may be a problem (or at least an annual service issue) if you have very hard water and do not have a water softner.

 

[KELLHAMMER]

Bosch does make a unit that fires from a piezo that generated from the flow of water in a little turbine thing. Only on the small WH not the big ones So if you on city water and you lose electric theoretically the water supply is still active and could still make hot water

 

[ovscrider]

i had one for 8 years in a lakehouse, nice thing was 20 people could shower in a row. Only issue outside of a flaw on install was needing the clean the filter in the unit, wife went up wiht some friens and had no hot water, I went up rinsed the filter reinstalled and it was fine. Driven point well so fair amount of sediment in it at times.

 

[olytdi]

I'm on year 11 with a Bosch Aquastar tankless with peizo igniter. Works flawlessly and froze once (used a hair dryer to thaw). Always have hot water in power outages and along with my gas fireplace, makes surviving a power outage pretty cush. I put a valve rebuild kit in it about 3 years ago just for maintenance sake.

ROI for me was about a year as the unit cost about $600 (my neighbor installed the gas line for beer and I installed the heater). My gas bill fell by over 50% once I got off the hot water tank treadmill. I was amazed at how much gas was being used to keep water hot 24/7 when I only needed it two or three times a day.

It's not big and wouldn't be adequate for a family but it is more than adequate for me and I really have been happy with it.

 

[MrMark]

Will be getting gas. Hot water still goes out with no power, I assume? Can anyone confirm.

Thanks again.

And yes, definitely a Rinnai, or higher end brand. The rebates and tax credits make it cheaper than a 40Gallon tank!

Yes, it needs to be plugged in to run. It has pilotless ignition and a microprocessor based control board with a ton of diagnostics and a flow sensor, etc. Most 40 gallon NG tank heaters do NOT need to be plugged in and run with no power.

Can you explain how you are getting your price comparison? 40 Gallon top of the line Bradford White NG is 500 dollars. A Rinnai setup is at LEAST 1500 just in parts. You need a sediment filter minimum on the Rinnai. To do recirc. you need a small electric water heater for a buffer. To eliminate the cold water sandwich with the Rinnai you also need the small 2-6 gallon electric buffer water heater.

Look at the Rinnai design guide you will see that they are fairly complicated plumbing wise to do correctly. I would guess you are looking at 2500 installed to do a Rinnai right with the buffer tank, and the filter setup. That's 5 times more than the tank heater.

 

[jlckmj]

I have seen tankless that are advertised as battery operated so no need for electricity,
However, I do not remember what brand it was.

Jim

 

[MrMark]

They absolutely (the Rinnai or Noritz) do not pencil out cost wise, apparently unless subsidized. They offer a couple advantages but the real only one worth talking about is space savings for a very small number of applications where this is an issue. For me this is very important but not a common issue I would think.

They have many disadvantages: cost, annual maintenance is a must the flushing with vinegar and you need a pump for that, complexity, cold water sandwich and difficulty of doing recirc (you need another tanked heater), no hot water potable water storage tank in the case of emergencies, no hot water with no power.

But they are **** and have great marketing and you can take a long shower.

 

[CNGsaves]

No power, no spark, no hot water.

If you have or plan on putting in a whole house generator, the benefit is less demand for electric, smaller generator.

Nothing keeping you from putting an UPS (uninterrupted power supply) on the 120v electric that would handle any outages in grid power. I bet your UPS would hold power for couple days so NG fueled tankless HWH would give you plenty of warm showers while power was out.

 

[plumbstupid]

I will not get into the ROI because it varies. We install Rinnai and Navien and both work great. If you are going to be installing a recirc system take a look at the Navien because they offer a model with a built in recirc pump and buffer take. If you install the Rinnai in recirc system you will have to install a small electric water heater to recirc the water thru.

The Navien can also be vented with 3' pvc pipe. The Rinnai requires their special vent pipe which is kinda expensive, but you can move them to a location where you do have to run it as far or you can mount it on a exterior wall.

I hear the Noritz units are outstanding but I have never had any dealings with them. I have also installed the Rheems which are made by Paloma and seem pretty solid.

If you are worried about the power going off I believe Paloma still makes a unit with a standing pilot, I had to work on one in a restaurant recently. IMO a standing pilot defeats the purpose of having a tankless WH

 

[Steroblan]

I have had a Toyotomi tankless oil fired water heater for 10 years and won't switch back to electric. Very low operating cost but it does require soft water. It has several safety sensors (low water pressure, low fuel pressure, over temp cutout etc). There is minimal maintenance but it's not for someone who isn't capable and willing to do light annual maintenance. Endles hot water. The generator keeps it going during an extended power outage.

 

[BBQ&Love]

My Bosch tankless is coming out today. I have to say I'm not very impressed. Long story short, even if the "water heater" part of the machine is in good shape, all the other parts of the machine are very expensive, as is diagnosing the issue with the machine, and the labor to get it fixed. Intermittent issues are very frustrating, and parts availability goes south long before the "lifetime" of your machine does.

Here is my experience.

I bought the machine in 2004. From 2009 and on, getting consistent ignition has been a problem. I've had the plumbers come in to look at it several times, and they didn't have any suggestions on how to make the machine light. If the tap was getting cold water, you just had to turn off the water and turn it back on again, and hope it lit this time. By the end of 2010 I was just turning the tap on, run for 5 sec, then off and on again EVERY time I used a tap. Plumbers came in, said there was nothing they could do... it appeared to be working correctly, there was gas and spark... just didn't catch.

Then last year, the motherboard went. Availability was a problem. It was a 3 week wait for the part, and for the price of the one part, I could have bought a new (tank) water heater. The plumber suggested that it wasn't worth fixing, but I figured if I got another 8 years out of the machine, then it would be worth it.... The new motherboard seemed to have a hotter spark than the old, so for the first month it worked like new... after 3 months, the no-light condition was starting to appear again.

Just last Thursday I came downstairs to find it acting up. With NO taps on in the house it was lighting the pilot, running the pilot for 10 seconds, then turning it off, and then re-lighting the pilot. it went on for a couple minutes.. I turned off the machine, and turned it back on again. Seemed good until I turned on a tap. Then it came on normally, but the burners DIDN'T SHUT OFF when the tap was closed. I turned off the machine again. Tried it again... this time the exhaust fan worked constantly, but the machine quit working all together. I read the manual front to back, re-set the sensor switch that activates the machine, but it would never turn on again.

The machine was unplugged and I called the plumber. A new 40 gal tank is going in this morning.

Typical. I want a tankless and it makes sense for my application. I recently bought a brand new Bosch for around $100 at Lowe's. It was large enough. I sold it rather than install it in my own house. I am a Master Plumber with tons of experience repairing them, but I can't bring myself to install one even if I basically stole it. I can't afford the repairs or the hassle.

"But I have one and it has worked great for 10 years." Yes, but when you are in the business, you start seeing patterns.

 

[ArkTinkerer]

I have a gas heater that is battery operated. Need to swap batteries about once per year. Problem is it doesn't adjust water temp automatically so with low flow you get scalding water and higher flows its cooler.

I worked around this by putting it in series with a smaller electric. The gas unit only comes on with larger usage and the electric adjusts the temperature. I also get backup in case either the gas or electric goes out.

Personally, I'm spoiled now and would not accept a system that went out if I lost electricity. I even had a period we were redoing the gas lines and I still had hot water for the couple weeks we were without gas. Life is good...

ArkTinkerer

 

[pmiranda]

I've had a Rinnai at home for a couple years now and it's been going just fine. I thought about getting a UPS so it would run if the power went out but it just doesn't happen often enough to worry about it.
Most of the extra plumbing is to allow for flushing. Otherwise, just needs a sufficient gas supply and you're golden.

 

[Voi]

Looking at a Rinnai. Anyone use any of these? With rebates, it ends up being cheaper than a standard heater. Was wondering approximate ROI time? Any major "cons" aside from startup cost?

TIA!

We remodeled our house back in 2010 and went with a standard (non-condensing) gas Rinnai. I'm not sure about ROI but our gas bill did go down despite adding a gas burning fireplace, cooktop and NG grill that we didn't have previously.

We have a 2500 sq foot two story and it is set up so that the three bathrooms and two laundry rooms share walls and/or are right over each other. The Rinnai is right in that area where all meet so we have very short runs from the heater. As such we don't have much of a problem with cold water lag. We do notice it at our kitchen sink which is the longest run from the heater. If my home were set up differently the lag might be an issue.

We do love it. We had a nice and nephew living with us this summer and it's nice to know that no matter what you won't run out of hot water.

It's not great to have showers in two bathrooms running at the same time as well has a dishwasher or washing machine. There is a drop off in volume of hot water produced. Two showers at the same time is acceptable.

I live in South Dakota and our water comes from a well pumping straight out of the Madison aquifer. No problem summer or winter.

 

[ddawg16]

Prior to do my 2-story addition I looked into tankless....this is basically what I concluded....

The payback on Gas is a LONG time....usually about the time you start getting payback, the unit is worn out. With electric, much better.

Your usage is a big factor on payback. If your the one shower in the morning...and then a couple hours of use in the evening then tankless is a good option...but if the wife is home all day and your usage is all day...then any heat losses through a tank are pretty much nill.

If your tank unit is a long distance from the use and a tankless gets it closer...the water savings and time offsets the higher cost of the unit.

A gas tankless unit takes a much larger flue vent than a tank unit.....I believe 4-5"

A gas tankless will most likely need at least a 1" gas line.

If you have electric...a hybrid tank is a better choice....it's basically a heat pump water heater.

With all the above said....there are no rock solid conditions on deciding between tank or tankless. I will eventually be installing a small one in my kitchen....just big enough to supply hot water for the kitchen sink and dishwasher.

One last thing....a lot of tankless warranties are void if not installed by a licensed plumber.

 

[James E]

I've had both Rennai and Navien. Had the Rennai in a 3200' home and it worked fine. Sold that house after 5 years and it's been working fine for the current owners for the past 4 years.

Put a Navien with a recirc system (on a timer so that it only comes on at peak times) in my current house. Love the recirc and have had only one issue with the Navien. After four years, it quit. Plumber came out and flushed it and it started back up again. He said he told me that would happen every 3-5 years (depending on water quality) but I swear I don't remember him mentioning that. Now he's dead so I don't know who I'll call the next time that happens.

When the power goes out, the hot water goes out but we're on a community well so when the power goes out, the water will go out after a few hours anyway.

 

[ddawg16]

A close friend replaced their gas water heater with an electric water heater.

Initially, she said it was great and their costs went down.

But now after 2 years of operation, and with higher electrical bills, the tankless is actually costing them about double per month what the tank gas water heater was. And now that they are over the newness of the tankless, they really don't need and endless supply of hot water.

In retrospect, she says the only advantage is the size. If she had it to do over, she would have gone with a 50 gallon/12 year warranty gas water heater.