Tankless water heaters

I an effort to be more environmentally aware and save money, we are looking into tankless water heaters.

Anyone use these? If so, can you give me your (honest and humble) opinion on:

  1. Do you have enough hot water to take a reasonable shower? Fill up a bathtub?

  2. Does this affect your laundry- we don’t do much using hot water, but would we be limited to cold?

  3. In short, did you notice any significant negative change?

Thank you!

It’s a tankless job.


boo, hiss

dis has got me tanking,

  1. Would it serve to have two units, one for each floor of the house?
  2. What about wait time, water waste while waiting for the hotwater delivery? Instyhot pump?

I just did this job a couple of months ago. I put one of these in.
There have been a couple of tankless threads since then, but since I can’t search…

  1. Enough hot water to take a shower? Umm yes, it is an endless supply. At whatever temp it comes out of the faucet, it will continue to come out at that temp until your gas gets shut off for non-payment. One of the big advantages is it has an endless supply.
  2. Affect the laundry? Not at all.
  3. It takes a few seconds longer for hot water to arrive at the faucet (no kidding about 5 extra seconds)
  4. Extra units? May not be practical, a recirculating pump might be a better idea.
  5. Like I said, a few extra seconds. (more on #4 and #5 in a minute)
    Never forget there is no such thing as a free lunch. Installation was not a snap, in fact it was a pain in the ass.
    I am on Natural gas, so the following comments are directed to gas units (natural and propane). Issues I had to face:
    [li]On a standard water heater, the water inlet/outlet are high ont he wall[/li][li]Again on a standard water heater the gas inlet is low[/li][li]On my tankless, all the fittings are on the bottom. This required me to lower the water pipes, and raise the gas line to fit.[/li][li]Here is the biggie, because I bought the great big unit I had to change the gas line from 1/2" to 3/4" This required some rather complex replumbing under my house.[/li][li]I could not find a flex line large enough to hook up 199,000 BTUs, so I had to plumb pipe all the way to the unit.[/li][li]This unit requires a 4" vent. Most gas WH require a 3" vent. I lucked out, when they built my house they put in a 4" vent in my ceiling.[/li][li]The unit requires some electricity (2A) to run the fan. I had to install a new outlet.[/li][li]Patching and painting of the wall will be required after moving the pipes.[/li][/ul]
    On the positive side, I picked up some floor space in a rather crowded laundry porch, so that is positive.
    The burner is proportional so if the draw is small, the flame is small, this saves gas.
    From the factory the unit comes with a remote that only allows a max of 120F. I found this to be a bit cool, particularly in the far bathroom. Too much heat loss in the pipe due to distance. However in the instructions for the unit tell you how to flip it over to a max of 140F. I find that 130F is perfect for my uses, and with that setting other than hearing the fan come on when I turn on the hot water (If I am in the kitchen or service porch) I can tell no difference between this and my previous tank heater in everyday use.

More on questions #4 and #5:
Additional units? If you are using gas, you would have to plumb gas to the other location (damn difficult in a already built house) and a vent (again may be damn difficult) If you are considering an electric unit, it might require a panel upgrade to handle the additional load. To go from a 100 Amp service to a 200 Amp service the prices start at about $1500 where I live. Plus you will have to have a new high amperage service brought to where you plan to put the second unit. more $$$.
A better idea would be to get a recirculating pump. This unit would go at the end of the plumbing run (upstairs bath room for instance) and when needed turns on, pulling the not yet hot water from the hot water pipe and recirculates it back into the cold water pipe. When hot water arrives at the pump a thermostat turns the unit off. I am considering one of these, so I don’t pour water down the drain. I was considering one of these before I put in the tankless, you know one of those, it sure would be nice to have home improvements.
I will probably also insulate the hot water pipes under the house to further cut heat and energy loss.

You might see if you can find the recent thread in GQ about the same subject. It had some relevant responses.

forgot to add:
My unit was about $400 more than a top of the line gas water heater. On the good side of this is it has about twice the life expectancy of a tank style heater.

While I was collecting bits to do the installation, a guy at the plumbing store told me professional installation for one of these start at $1000. I would classify this job in the advanced do-it-yourself category for gas, and probably not at all a DIY project if you are doing electric.

Pictures of the install

Search is back-- now I can try to find it!

Rick: tanks (ahem) for the info-

Agree with Rick on all points. Except that I wouldn’t in a million years try to self install. When dealing with gas, aren’t you supposed to have a professional do it? Clearly Rick has the necessary skilz, but I wouldn’t touch it.

I think we spent less than $3,000 on ours with installation. Our unit is rather large as it serves a three bathroom house and I have a wife and two daughters (The girls are only 6 and 4, but my plumber is forward thinking.) Our house was renovated in 1998 by some guys who really didn’t skimp on much so we didn’t have any problems with the gas line. Conversely, my boss lives by herself in a smallish 2/2 with OLD plumbing (water and gas) and I think she spent more than $5,000 on hers, mainly because of the gas line issues.

If that was the case, you wouldn’t find gas fittings at Home Depot. It’s just the type of job that most people shy away from, since if you screw up, you can end up dead. But I’ve never heard of any requirements that say a pro has to do it.

I agree with Rick on all other points, as well, but I so agree with you, here. My husband has done a bunch of work on our house himself, including plumbing and electrical, but he hired a plumber to install the tankless water heater.

The only other thing that I would add is that, due to the lag in the hot water flow, adjusting the shower the way you like it can be a little tricky. But you do get used to it after a while.

I love the idea of tankless waterheaters, but after the experience that my folks have had, I’d stay far away from electric ones. They have a cabin (with a conventional tank water heater) and a nearby second building, with an occasionally used shower. Seemed like the perfect place for a tankless heater. Unfortunately, they only have electricity as a power supply. Both of the electric heaters they installed were a huge bust. It seems that the electric heaters are either on or off (duh) with no gradiant in between. So you either have lots and lots of very hot water, or you have none. It maked for very interesting showers.

I am a Plumbing/HVAC contractor and we sell the Rinnai brand. I’m extremely happy with them.

I don’t know who’s quoting $1000, but I can tell you that our material cost is roughly $1000 for a unit, flue material and misc stuff. (that’s material cost; no markup, no labor) We sell then for around $2500 and I was a training class a couple weeks ago and was told by one HVAC contractor that they were selling them for $3900!

Rick has much higher skills than average. I would generally consider this to be an advanced DIY if at all; and if you have no experience with gas lines, soldering copper etc I would generally say that this is not a DIY job.

There are some gas units out there that do not require electricity to start the fire. I was going to put one in but discovered that my gas line was not large enough. Not the line under my house, it is 3/4, the pipe in from the street is only 1/2. :confused: Couldn’t afford the cost of getting that taken care of as well as the re-plumbing of my water pipes in the laundry room. (Which needs to be done anyway, but not until I can afford to get it all at once.)

The $1000 was for install labor only. My unit was right at a grand, and other miscellaneous shit was probably about $200- $300.
After completing the job, if I had a neighbor that wanted one, I would not bid it for less than $1500 for the install labor.
As far as plumbing the gas line goes, Doing gas with black iron pipe is just like doing water with galvanized pipe. Righty tighty, lefty loosey. Use teflon tape on all the joints. Leak check it when you are done.* Really it isn’t hard running gas line. When I first bought this house, I ran a 3/4" gas new gas line all the way from the meter to my back patio for a BBQ. The hardest part of that job was drilling the foundation in 2 different places. On this water heater job, the part of it that was a bitch is that we had to go into an existing gas line, cut out a 1"X1/2"X1" tee that connected to a 1/2"X1/2"X1/2" tee and change it to a 1"X3/4"X1" that connected to a 3/4"X1/2"X3/4" This required some unions and some serious dinking around under the house.
IMHO opinion sweating copper pipe is harder than plumbing gas lines. Particularly now that you can’t use lead solder.

*So when I was a kid my dad had me help him move a gas line in our house (He worked in construction, and built the whole house by himself) anyway we were talking about leak checking, and he said we could use a match.
:eek: WHAT?
Oh sure, he said, as long as you don’t have an accumulation of gas, it really isn’t a problem, you will just get a small flame. here I’ll show you he said.
He left the last union a bit loose, and put a match near it. Sure enough a little flame come out of the joint. At that point he turned off the gas, and tightened the joint. FTR we then used soapy water to check all the joints in the system.
Bottom line is even if you put it together a bit loose and have a leak, it does not automatically mean your house will wind up in orbit. You always have to leak check each joint you work on.