Hello
I had my hot water heater go out, it is located in a crawl space about 4′ tall. The old heater was gas fired, not very tall and pretty big in diameter made by Rheem. I’m having trouble finding a replacment for it and I’am considering a tankless system. Rinnai model2532-FFU was one of the ones I was looking at. There are alot of choices out there and alot of price variations. I have 2500 square foot home with 2 baths. What do you recommend ? What would be reasonable cost for a unit and an average installation?
Replies
Rinnai has a good reputation, although I am not familiar with the specific model you mention. If you want to install it in the crawl space, you need to check that it will have the needed clearances above and below the unit, and that you can vent it easily--the vent pipe is not the same type as the Rheem uses, and is fairly expensive.
The easiest installs for tankless heaters are on exterior walls, either inside the house or outside. On the outside, you simply hang the unit and it doesn't require a vent pipe at all (as long as you have the needed clearance to doors and windows). On the inside, you run a vent straight out thru the wall (same caveat as above). Locating it where it needs much of a vent pipe is the third choice.
Rinnai certifies installers for its hot water heaters. I would contact them, or contact a distributor, and get a referral to a certified installer. Or, call a plumber who specializes in tankless, and consider another brand. We're about to install a Takagi TK1s, which cost just a hair over $1000. I would estimate the installed cost thru a plumber at closer to $2000, depending on the complexity of the job. If they can't put it in the crawl space, they will have to extend the water and gas piping.
The main issues with tankless heaters are: peak output (i.e. can you run the dishwasher, the clothes washer, and both showers at once... probably not), low-flow output (does the bathroom sink flow enough hot water to kick the unit on), and gas pipe sizing (does the existing gas pipe supply enough gas for the unit... it uses a lot more than the Rheem).
Also to be considered is water hardness.
If you have hard water, scale deposits will form in the heating coils reducing efficiency, requiring a you to flush the coil with a scale remover.
I asked a similar Q a few months ago.
do a search on tankless WH's
I'm probably gonna get a second conventional and put it in series.
I'm Financially challenged so $300 vs $1200 was the kicker.
900 bills will buy a lot of tools!!!
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I'm also looking into these, do they make an electric model.
Yes, they make electric tankless WH.The main "problem" with them is that they need lots of current. Typically 3 or 4 30 amp circuits for a total of 90-120 amps.Also for any tankless you need to be aware of what you incoming water temp is in the winter.They are speced by temp rise. And if the water is very cold then they the flow rate for a given output temp is reduced.
Check out the Seisco. (I think it's Seisco.com)The big one runs on four 30-amp circuits, but doesn't pull anywhere near that much juice.I like the Seisco's because they're made totally of engineering polymers; no metal, except the elements. I have a four-chamber model in my house. Reputed ROI over a tank-type is about 18 months, due to energy savings.
Thanks Steel buddha,
I'll need to check if I have room for that amperage.
Electric Tankless & D-Mix. What a combination! We also have a Seisco BIIIIIG Mother. It will parboil you if you let it./ My DW comes out of the shower looking like a boiled shrimp. I can't handle it. Been using it two yrs now, and absolutely love it. It is only 3 ft from the service panel, so its wires (cables) are short, but when it kicks in the lights momentarily dim. Sorta like testing "The Chair" in an old Mickey Rooney prison flick. We have 200 amp svc, but sucking 120 amps out of circulation momentarily does load the power grid. Lights come back to full brightness in a few seconds. We parallel load it frequently w/ a dishwasher & never notice it. When our flock of kids & grandkids descend on us, we never want for HW.It's the way to go. Especially if your utility room is space challenged. Also, nothing to rust.Don (of D-Mix infamy)The GlassMasterworks - If it scratches, I etch it!
Hello All,I have a tankless gas water heater and I would never go back to a tank. Unlimited hot water and extra closet space!!! The only drawback is that your dishwasher may have problems. The line feeding hot water to the dishwasher does not flow enough to cause the water heater to heat the water, at least in ours. This caused some funky results in the dishwasher until we turned off the energy saving feature. Then the dishwasher would heat the water itself. Vaughn
Many folks want to go tankless with the idea of saving energy from standby losses. The reality is that standby jacket losses on a modern tank are very low, to the point of being relatively insignificant.
To the extent that some of the tankless units have better combustion efficiency, there is some energy saving benefit, but the cost can be prohibitive.
If you happen to have a boiler, consider an indirect tank as well.
My bathrooms are so far from the water heater, I've got to run the water for 3-5 minutes before it gets hot. I'd love to have an on-demand for showers on the second floor. Could mean some major repiping howver.Also, we do lots of laundry, I'm told these devices don't keep up well with washers - it that true only on the "hot wash" cycle or are there issues with the "warm" wash cycle? (of course if you are using the high efficiency - low water use washers from Maytag or Whirlpool I bet it's not an issue at all)..Mark
Measure it with a micrometer, mark it with chalk, cut it with an ax.
Mark-
Might want to check out the D'Mand system from so far away from the heater..I will probably use it along with my rinnai.
Johnny
http://www.gothotwater.com/D%27MAND/tankless.asp
We had an Aquastar 125S installed in our house. The unit cost ~600 bucks when we bought it 3 years ago. This is the more expensive 'S' model which means it can modulate its heat input all the way down to zero depending on incoming water temp. Its meant to be used with solar hot water pre-heating. As far as I know its the only tankless unit that can do this. We have yet to install the batch heated solar hot water system but the tankless heater is still going strong.
Maybe it does not cost that much anymore to keep a 60 gallon tank hot (I like my showers HOT) but you will eventually run out of hot water with a tank unit. Another savings is that the tankless units last FAR longer than conventional with all user replaceable parts. It can literally be the last water heater you buy ever.
There is only two of us and we do have to do things serially but so far that has not been a problem. We have a modern clothes washer and dish washer.
We had four guests staying with us and they were absolutely amazed that they could all take loooong hot showers one after the other and not run out of water. One thing I have noticed is that once you explain to your house guests how it works, they end up taking WAY longer showers than they normally would.....cheap friggen in-laws!
About this running several things at once idea. I have NEVER lived in a house where that was possible no matter what kind of hot water heater we had. If you were in the shower you KNEW when someone turned a faucet on or flushed a toilet. Maybe its because I grew up in crappy one-story ranchers in SF bay area with low water pressure and bad plumbing designs? But I would be curious to know how many people can actually do that anyway?
Daniel Neuman
Oakland CA
Crazy Home Owner
In my house growing up, my dad would turn on the hot water fawcet to get us out of the shower (it got cold fast).Now, I can run two showers and a dishwasher and not notice - 40 gallon tank sitting in the basement. The only time I can get ahead of the WH is when we fill the jacuzzi.With 3 kids, parallel use happens a lot - we are always running laundry, 1 -2 loads of dishes a day and 3 "pre-teen" showers, 2 adult (shorter) showers a day. Dishes and kids get washed after dinner - laundry goes all day. So our peak load time is post dinner. No one complains about water.Mark
Measure it with a micrometer, mark it with chalk, cut it with an ax.
Hi Mark,
What do you think the difference is between the two situations that let you run things in parallel?
With 3 kids, parallel use happens a lot - we are always running laundry, 1 -2 loads of dishes a day and 3 "pre-teen" showers, 2 adult (shorter) showers a day. Dishes and kids get washed after dinner - laundry goes all day. So our peak load time is post dinner. No one complains about water.Daniel Neuman
Oakland CA
Crazy Home Owner
Capacity and water pressure also I think the dishwasher and showers are fed from the same branch. Washer is fed from a diff branchMark
Measure it with a micrometer, mark it with chalk, cut it with an ax.
What about installing a hot water recirculating pump?
It's not just the pump, it's the return piping...
"My bathrooms are so far from the water heater, I've got to run the water for 3-5 minutes before it gets hot."
This is the situation for which I was suggesting the recirculating hot water pump. Current energy standards recommend reciculating pump to eliminate this 'wasted' water while waiting for the 'hot' water.
Right, I'm just pointing out that he would need to install return piping to complete the loop from those distant fixtures. In a finished house that can mean opening a lot of walls.
No need for a reutrn line.They use the cold water line.Now that means that the cold water is usually on the warm side to start with, but in general most people can live with that.
We always do recirc with a separate 1/2" return for the hot, leave the cold.... cold
Well that is the prefered method.But when you are doing a retrofit that is not always practical. In fact several brands are advertised that they don't need a separate return.So you have the options;A) living with a long wait for hot water.B) spending several thousand $ to opeen walls and running a return line. Might be in the 10's of thousands depending on the finishes involved.c) spending well less than a 1k for a system that uses the cold water for return.http://www.rewci.com/whhohotwaci.htmlTake your choice.
Of course no one is going to open all the walls just to put in recirc piping. Well, not exactly no one, because some owners are wealthy enough to say 'just do it', but that's about 2% of people.
I've never dealt with a system that used the cold for a return line, but it seems like it would cause the opposite problem, at least to some extent. Sure, you have instant hot water at the shower, but the shower gets colder as the hot water flushes out of the cold line. Or, you're brushing your teeth with warm water. As a simple retrofit, there might be some advantages over not having it at all, but it won't be nearly as convenient as a true recirc loop, and convenience is what it's all about.
I have an on-demand tankless Lion Water Heater from 1907. It is cast iron, with a gargoyle style lion head cast in the door. It is about 2' tall and 8" in diameter with a 20' long copper coil inside and a gas burner in the bottom.You have to light it with a match, but it heats water as fast as it flows through the coils. So, the tankless design is not a very new idea. This simple, old water heater would still work well for an occasional use cabin. Actually this old heater is still in service (not heating water though); I converted it into a lamp. I'll post a photo sometime.
Please do !!And may "sometime" be soon.: )
The person you offend today, may have been your best friend tomorrow It is easy to be friends with someone you always agree with.
I'm still using "gotta take a few more pictures to finish that roll" technology.Might be next week, so I'll post it here and in the Photo's folder as "1907 Tankless Water Heater.I get some interesting looks when I tell people I turned a water heater into a floor lamp (they are thinking, "you got a big 40 gallon white thing in your living room, as a lamp?!").
Please post a reply to me when you do, so I don't miss it.: )
The person you offend today, may have been your best friend tomorrow It is easy to be friends with someone you always agree with.
Bill, Have you ever installed this system or know anyone that has? I've been considering getting this setup but was wondering about the reliability of the valve that goes under the sink and the overall operation. Can this cause any problems with the existing pipes or water heater down the road? -Ed
No, just heard some of the local plumbers advertising it or one similar.
I've installed the Grundfos Comfort system for a customer, they love it. Had to use two bypass valves - large house. One valve did fail after 3 months, Grundfos had a replacement to my house next day!
Water temp is an issue if your water is cold well water several gallons may have to run though the system prior to reaching a heated temp. Water pressure is another issue. If you are on well water you need at least a 30 to 55 pressure tank to effective run an on demand