Tankless water heater? Any experience?

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rookie7

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Jan 26, 2009
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#1
I have a 50 gallon and a 30 gallon water heater in my crawl space. The 50 is leaking from the fittings where the inlet and outlet pvc connect to the top. Probably not a good idea to drop money into it since the water heater is 20 years old.

Looking at replacing it with a Rheem tankless. Does anyone have any experience with a tankless? Regrets? Definite yes?
thanks
 
#3
We had one put into our rental property out in Lubbock; worked well, despite being a cheaper unit. It was electric and was kind of expensive to run though.

We put in a higher-end Renai unit in the casita we just built, and love it. It’s on propane, and works great feeding the shower and sink, as well as a sink out in my detached garage. Endless, on-demand hot water.
 
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#10
We have a heap of those here. Rheem or Rinnai. Rinnai are the best. Not sure how they are rated there. The standard domestic one we put in here is around 26l per minute at 25 degree rise (metric measurement) or 16l per min at 40 degree. Ok if you only use one tap at a time.
 
#11
rookie7 said:
I have a 50 gallon and a 30 gallon water heater in my crawl space. The 50 is leaking from the fittings where the inlet and outlet pvc connect to the top. Probably not a good idea to drop money into it since the water heater is 20 years old.

Looking at replacing it with a Rheem tankless. Does anyone have any experience with a tankless? Regrets? Definite yes?
thanks
Click to expand...
I have one. It’s great. 10 yrs. No problem thus far. Never run out of hot water! I have the rinnai
 
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#13
Rinnai gas ones are excellent. We had the 190k BTU non condensing LP unit in our house. Burn about 120 gallons a year with 4 people in the house. It is awesome. It would do 8 gpm if I remember.

Electric ones are a pain and expensive if your installing afterwards. Expect 3-4 40 amp circuits, pretty much need another 200a panel to feed it
 
#14
rookie7 said:
I have a 50 gallon and a 30 gallon water heater in my crawl space. The 50 is leaking from the fittings where the inlet and outlet pvc connect to the top. Probably not a good idea to drop money into it since the water heater is 20 years old.

Looking at replacing it with a Rheem tankless. Does anyone have any experience with a tankless? Regrets? Definite yes?
thanks
Click to expand...
Endless hot water is awesome unless you have teenagers
 
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#16
And not one person mentions a thing about the scale build up and annual, or at least bi-annual clean outs with stinky assed vinegar (when it gets hot) and those type of downfalls.

Yea I have extensive experience with the Rennai units......seems more than anyone else here huh ?

They suck, bad.
 
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#21
Gemsbok said:
Anybody have longevity experience with propane tankless? Home Depot costs are 2-3X a 50-gallon tank unit.
Click to expand...
Your water wreck stuff ?

They claim 15-20 years maintained. I’ve replaced thousands of tank heaters that the bottom rusts in half, I’m sure that plays a factor in longevity.
 
#22
I looked into them recently and went with a tank. I have all electric. yea you need alot of juice to run them. The electrical hook up is well worth the research .
 
#23
Pretty much all of the apartments I stayed in over the years when I worked in South Korea had them.
The honest truth however I'm not entirely sure how much in the apartments ran off of the small system that was visible and what was coming from a boiler system.
The heating systems were floor heat and pretty damn touchy, several times I came in from work and it was cold so I turned the heat up a little or so I thought. Whent out with coworkers for some diner and drinks and came home to a fucking sauna.
 
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#24
If you do a recirculation run they work great. This might be hard to do in a remodel but the builder I do consulting for puts them in all his larger custom homes. I will do one when my tank goes (or sooner), I get free water, and have two water-waster shower heads in my master. (have good water from a 23gpm well, so it's pretty much free)
 
#26
I also have a Rinnae in the house. Been in 12 years with not a problem. Agree with the comment on teenagers. If I had it to do over I would have put one in near our master bath also. The unit is at the kitchen and hot water is instant. It takes a while to get hot water across the house to the master bath.
 
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#27
I only run into Rheem water heater questions on days that end in the letter 'y'.

Dealing with an estimate right now.

An electric water heater from them just for a pool can take up to 3 240 volt 40 amp breakers.

Most instant water heaters capable of producing a hot shower are going to be of the three 240 volt 40 amp circuit type. Not only do you need the space on the buss bars of the panel.

The job I looked at on Friday has gas central heat in the house and had a gas pool water heater. However, the model they have chosen may work. 11 kW, a 2 pole 60 amp circuit. Main breaker is 150 amps. I did an amp draw and it was 24 amps. So, not bad. Working amperage of the unit is 45 amps.

Only problem is there is no easy way from the panel to the pool equipment. Panel is on a wall in the garage, back to back from the meter base. Equipment is on the exact opposite side of the house. 2 story house with no usable attic space.

Anyway, so, it is matter of how much service you have. Most modern houses have 200 amp service and the power company actually brings you 67 percent ( I learned from a lineman at Texas-New Mexico Power.)

If you have a big service, such as a 320, you might be okay.

Otherwise, stick with gas water heater with a 40 gal tank. Cheap to run. And just as ""green" as anything else.
 
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#28
n2ishun said:
And not one person mentions a thing about the scale build up and annual, or at least bi-annual clean outs with stinky assed vinegar (when it gets hot) and those type of downfalls.

Yea I have extensive experience with the Rennai units......seems more than anyone else here huh ?

They suck, bad.
Click to expand...
I’m on my 2nd rinnai. Natural gas, city water. 18 years on the 1st rinnai, never once did I rinse with Vinegar. Never needed to.

Guess it depends on where you live, and the quality of your water.

They do not suck.
 
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#30
One thing to consider is that is was $1000 to install it. The guy did some crazy stuff but still $1000.
IMG_0736.jpeg
 
#32
I have a natural gas powered Navien. I bought it due to an energy efficiency rebate and the fact that I have a small garage and wanted to maximize on available space. If I did it again I would probaly go with a solar water heater as where I live is warm most of the year and has lots of direct sunlight.
 
#33
Jgore said:
My runnai runs hot for about 12-13 minutes and goes cold. It’s never been serviced and it’s about 8 years old. Any ideas? Do they need servicing periodically?
Click to expand...
I haven’t had to have mine serviced. Not sure. But if u find out what’s causing it, please post about it. I’d like to know!
 
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#36
I have had 3 different ones, problems with 2 of them. Also they use 2-3 times as many BTUs to heat water. Propane or natural gas 40 gallon power vent unit in new house.
Also you should have CPVC on hot side PVC for cold water only.
 
#37
I've had a natural gas unit for 6 years now. I've always done the annual descale with vinegar and clean the carbon off of the igniter.

Maintenance is easy, requires 1 hour per year. I would get twice the size that the charts recommend.

Had a dual tank system previously and had the bottom rust out of one of the tanks.

The space saving aspect is one of the big positives.
 
#38
Takagi is what I've used at our house for hot water and hydronic heating. If you have hard water, then some sort of treatment will be necessary or else you'll get good at replacing heat exchangers. We do a traditional water softener on the whole-house supply, and then an additional 3M Aqua-Pure scale cartridge on the heater inlet.
 
#39
I have had both.

Rinnai powered by gas - won’t get scalding hot like a tank but it never bothered us. Small and no issues in the 5 years I had it. For a 3,000 sf house with 2 young kids it was fine (9 & 10 1/2). Gas bill went down 50%.

My new house has 2 big Rheem tank heaters powered by gas. Never run out of water. Gas bill is higher but it’s a bigger house and my kids take longer showers.

I personally liked them.
 
#40
If you've got gas, go for it. Electric I would not do it.

I had an electric unit years ago for the whole house. It had three heating elements in it, each on a separate breaker. The elements would die on occasion and if one went out you were taking a cold shower. They replaced them but what a pain in the ass.

The last straw occurred when I was backing out of the garage and hear a loud pop then instantly saw water flowing down the wall from the box. The element had gotten so hot it melted the thermoplastic housing the element. Had it replaced with a tank unit.

Traded the replacement to my buddy for his workshop. It's fine in that setting and still going strong after 15 years but they aren't enough for a whole house situation.
 
#41
I have a Bosch propane one. It’s totally non-electric. It’s been running problem-free for 13 years. I did vinegar flush it once, about a year ago.

I like it. No floor space at all, I installed it over a utility sink. High ceiling garage.
 
#42
XLR308 said:
Pretty much all of the apartments I stayed in over the years when I worked in South Korea had them.
The honest truth however I'm not entirely sure how much in the apartments ran off of the small system that was visible and what was coming from a boiler system.
The heating systems were floor heat and pretty damn touchy, several times I came in from work and it was cold so I turned the heat up a little or so I thought. Whent out with coworkers for some diner and drinks and came home to a fucking sauna.
Click to expand...
HAHAHA. I had an apartment in Koza, Okinawa. Tankless water heaters; they were always installed on an outside wall, had pilot lights which were constantly blowing out on windy days. Four stories up on a service balcony wrapped in a towel trying to get pilot relit. Wet, shaking like a dog shitting 2x4's. FUN!!
 
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#43
rookie7 said:
I have a 50 gallon and a 30 gallon water heater in my crawl space. The 50 is leaking from the fittings where the inlet and outlet pvc connect to the top. Probably not a good idea to drop money into it since the water heater is 20 years old.

Looking at replacing it with a Rheem tankless. Does anyone have any experience with a tankless? Regrets? Definite yes?
thanks
Click to expand...
I built a pole barn on my small ranch in central Oregon, complete with two small apartments for family and friends, and maybe someday to generate some income. I installed the tankless water heater below, and it's been amazing, especially for a property that sits empty most of the time when nobody is visiting. The only down-size is that for a water heater that is bulky enough for a residence, it (at least this one) required three 40-Amp circuits ... luckily we were building at the time so it was easy to plan for this. Retrofitting existing space might not be so easy. That said, we are super-happy with this tankless water heater, and for the last half-dozen years, I've been waiting for the water heater in my ranch-house to fail, so that I'd have an excuse to go tankless in the main house.

 
#44
jamesd said:
Also you should have CPVC on hot side PVC for cold water only.
Click to expand...

I’m not sure if you’re referring to my picture above your comment or if you were just stating that in general, but the PVC pipe you see in the picture is for the condensate drain. You cannot use metal fittings for condensate water because of the pH of the water.

The exposed red PEX pipe is the T&P safety valve.

The three insulated lines coming down the wall are the hot cold and recirculating pipes, which are also done in PEX pipe.

I wouldn’t run CPVC pipe in my doghouse that shit gets brittle as hell after a few years, especially on the hot side. I would rather have polybutylene pipe with the metal fittings, than CPVC.
 
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#45
n2ishun said:
the scale build up and annual
Click to expand...

It's real.

We have a tankless, Rinnai or whatever but we've also had a whole house filter/softener for 9 of the 10 years we've been in this place.

I don't recommend tankless without some kind of filter upstream from it to remove every particle of anything from the water that hits it. Plain old water heaters struggle enough to survive "treated" water.

Even with the ginormous filter setup I had to break mine down once because it stopped heating water. Wasn't sure if if was a connection issue or a gas issue ... turned out it seemed to be a crud caked flow sensor of some kind that looks like it regulates the gas burner ... no flow, no fire apparently.

It's the only problem I've had with mine in 10 years but I credit that to running nothing but near distilled purity water through it.
 
#46
I have two Navien powered by propane, they work great and they are set to circulation. Prior I had a 75gal WH and two 36gal boilers. I did have to install a whole house water filter with a brine tank because of the hard water. Getting rid of the hydronic heating and switching to heat pumps , going to tankless has cut my utility bills in half. I pay .05KW for electric and propane is expensive. I would not do it without natural gas or propane. I also have an all copper water pipe house.
 
#47
We have a 20 year old Rinnai unit (propane) at our house and it's still working perfectly (knock on wood). We have well water running through a softener, not sure if that makes a difference. My only complaint would be that it takes quite a bit longer to get hot water at the faucet vs. a traditional unit. But once it gets hot, it never runs out. I won't run a traditional water heater again.
 
#48
I'd love to find a really small 120V "supplement" for my kitchen until the real hot water from the tank comes over.

All electric house; so the best I could do is a heat-pump model tank since my garage is > 80 degrees 8/12 months. The power requirements for a tankless is extreme (50A or more as somebody said - damn near have to put a new service in).

But primarily interested in kitchen myself. Now, if I built a new house, I'd have a tankless main (or maybe two depending on how the house was plumbed).
 
#50
Whiskey Tango Foxtrot said:
50 amps
Click to expand...
This sir might be a smaller unit

I thought there was no way I was seeing this correctly so I had to take a pic to share it with some folks.

I was in Menards I believe waiting for a worker to get me something. While standing there waiting looked over the specs on those things. Some were over 100 amps.

IMG_1944.jpeg
 
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