# Tankless water heaters -- any experience or advice? **URL:** \ **Category:** In My Humble Opinion\ **Created:** [February 25, 2015, 12:18am UTC](https://boards.straightdope.com/t/tankless-water-heaters-any-experience-or-advice/713559 "2015-02-25T00:18:14Z")\ **Posts on this page:** 16\ **Page:** 2
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [February 25, 2015, 5:21pm UTC](https://boards.straightdope.com/t/tankless-water-heaters-any-experience-or-advice/713559/21 "2015-02-25T17:21:20Z")
you have 100 A of 220 V. not enough. ---
**Author:** ![John\_Mace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_mace/32/185_2.png) [@John\_Mace](https://boards.straightdope.com/u/John_Mace)\ **Post date:** [February 25, 2015, 5:35pm UTC](https://boards.straightdope.com/t/tankless-water-heaters-any-experience-or-advice/713559/22 "2015-02-25T17:35:58Z")
I have one in my house, but it’s gas. It takes a bit longer to get hot water (not much, but sometimes those few seconds seem like a long time), but I’m gone a lot and it saves quite a bit of money since I’m not heating water when I don’t need it-- which is a goodly amount of time. Mine is a Toshiba, and I’ve had it for about 6 years w/o any problems. (Knock on wood.) ---
**Author:** ![mmmiiikkkeee](https://avatars.discourse-cdn.com/v4/letter/m/edb3f5/32.png) [@mmmiiikkkeee](https://boards.straightdope.com/u/mmmiiikkkeee)\ **Post date:** [February 25, 2015, 5:37pm UTC](https://boards.straightdope.com/t/tankless-water-heaters-any-experience-or-advice/713559/23 "2015-02-25T17:37:54Z")
> [@racepug](#): > > …and now with some of the faucets (in particular the kitchen one, in our case) it seems to take forEVer for hot water to come to it (or, at least, certainly longer than it’s supposed to). Next time we have the guy come by (I think you have to have the pipes cleaned at least once a year because of the buildup associated with tankless water heater systems), which should be pretty soon, we’ll have him look into that. I don’t know of any kind of build up associated with tankless heaters…? One thing I missed in my previous post was that there is also a minimum flow required to trip /open the valve or switch which tells the heater water is flowing. If you just crack a faucet and have water trickle through, the heating elemnents won’t come on. This is occasionally an issue when you have a combination of low water pressure and small (or clogged) water lines; without sufficient flow the heater won’t “know” it’s supposed to be heating and you’ll get either no heat at all or insufficient heating as the elements switch on and off as the water flow trips the switch intermittantly when it’s right on the verge of being insufficient. Try turning on another hot water tap to increase the overall flow rate through the heater and see if the water gets hot properly… if so you may just have insufficient water flow; that’s not the heater’s fault though. They have safety features (at least better ones do) that keep the elements from blasting inferno-level power and either melting their own wiring or vaporizing a tiney trickle of water going through caused by one of your hot water faucets with a slow leak. ---
**Author:** ![Renee](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/renee/32/287_2.png) [@Renee](https://boards.straightdope.com/u/Renee)\ **Post date:** [February 25, 2015, 6:03pm UTC](https://boards.straightdope.com/t/tankless-water-heaters-any-experience-or-advice/713559/24 "2015-02-25T18:03:49Z")
> [@johnpost](#): > > you have 100 A of 220 V. > > not enough. Correct. This is a non-starter unless you increase your electrical service, which is quite expensive. ---
**Author:** ![Musicat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/musicat/32/20189_2.png) [@Musicat](https://boards.straightdope.com/u/Musicat)\ **Post date:** [February 25, 2015, 6:07pm UTC](https://boards.straightdope.com/t/tankless-water-heaters-any-experience-or-advice/713559/25 "2015-02-25T18:07:41Z")
> [@racepug](#): > > My first thought: 60 years?!? Holy Cow! Ours didn’t last more than about 10!.. I was surprised, too, but like the energizer bunny, it just kept going and going… Do you have any comments on the electricity usage reduction after the switch to tankless? Was it significant? ---
**Author:** ![Musicat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/musicat/32/20189_2.png) [@Musicat](https://boards.straightdope.com/u/Musicat)\ **Post date:** [February 25, 2015, 6:11pm UTC](https://boards.straightdope.com/t/tankless-water-heaters-any-experience-or-advice/713559/26 "2015-02-25T18:11:04Z")
> [@Renee](#): > > Correct. This is a non-starter unless you increase your electrical service, which is quite expensive. I’m going to find out from an electrician, but is it possible the box can handle more than the installed circuit breakers would indicate? It’s half empty! ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [February 25, 2015, 6:19pm UTC](https://boards.straightdope.com/t/tankless-water-heaters-any-experience-or-advice/713559/27 "2015-02-25T18:19:35Z")
the main breaker at the top is the input. you can’t get out more that that no matter how you split it up. if you draw more than 100A then then power to your house will shut off. ---
**Author:** ![Renee](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/renee/32/287_2.png) [@Renee](https://boards.straightdope.com/u/Renee)\ **Post date:** [February 25, 2015, 6:30pm UTC](https://boards.straightdope.com/t/tankless-water-heaters-any-experience-or-advice/713559/28 "2015-02-25T18:30:58Z")
You’d have to bring in new wires from the street. It’s a major job. I know you dismissed the propane option, but if your water heater is on or near an exterior wall, it’s really not a big deal to put a 100lb propane tank outside, and do a direct vent water heater. Nowhere near the $5K you suggested. As a DIY project, I’d estimate about $250 plus the cost of the water heater. ---
**Author:** ![Chefguy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chefguy/32/138_2.png) [@Chefguy](https://boards.straightdope.com/u/Chefguy)\ **Post date:** [February 25, 2015, 7:30pm UTC](https://boards.straightdope.com/t/tankless-water-heaters-any-experience-or-advice/713559/29 "2015-02-25T19:30:19Z")
We had a propane tankless put in after we bought this house five years ago, partly for the energy savings, but also because there is no floor drain in the basement. It saves a lot in energy costs over a conventional heater, and the hot water is limitless. We had to have a separate gas line put in from the meter (which is usually the case). Maintenance has been limited to cleaning out the tiny inline filter from time to time, which is a five minute job. Since the usage points are half a house away from the source, it can take 30 seconds or so to get hot water to the tap, but it’s hardly an inconvenience. ---
**Author:** ![Dewey\_Finn](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dewey_finn/32/4222_2.png) [@Dewey\_Finn](https://boards.straightdope.com/u/Dewey_Finn)\ **Post date:** [February 25, 2015, 7:47pm UTC](https://boards.straightdope.com/t/tankless-water-heaters-any-experience-or-advice/713559/30 "2015-02-25T19:47:46Z")
> [@Musicat](#): > > > [@racepug](#): > > > > My first thought: 60 years?!? Holy Cow! Ours didn’t last more than about 10!.. > > I was surprised, too, but like the energizer bunny, it just kept going and going… > > Do you have any comments on the electricity usage reduction after the switch to tankless? Was it significant? If you’re going from a 1955-era water heater to a modern one, I’d expect that you’re going to see energy savings even if you stick with the type that uses a tank. (The modern ones have better insulation, for one thing. And my parents rent their water heater from the electric utility and the one that’s there now has some sort of timer that reduces the amount of water produced during the day and can be set for vacation mode.) Also, check with your electric utility. They may offer a rebate for upgrading the water heater. ---
**Author:** ![MindsEye\_Watering](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mindseye_watering/32/3619_2.png) [@MindsEye\_Watering](https://boards.straightdope.com/u/MindsEye_Watering)\ **Post date:** [February 25, 2015, 8:44pm UTC](https://boards.straightdope.com/t/tankless-water-heaters-any-experience-or-advice/713559/31 "2015-02-25T20:44:31Z")
nm ---
**Author:** ![toofs](https://avatars.discourse-cdn.com/v4/letter/t/4491bb/32.png) [@toofs](https://boards.straightdope.com/u/toofs)\ **Post date:** [February 26, 2015, 3:34am UTC](https://boards.straightdope.com/t/tankless-water-heaters-any-experience-or-advice/713559/32 "2015-02-26T03:34:50Z")
Two of my neighbors have them. A Noritz and a Rheem. In our neighborhood, standard tank water heaters are installed in the garage, taking up valuable floor space. Mounted to the wall, the tankless units create a newly usable space for things like motorcycles. I want one to increase my usable garage space, rather than any energy savings. ---
**Author:** ![BigT](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bigt/32/12044_2.png) [@BigT](https://boards.straightdope.com/u/BigT)\ **Post date:** [February 26, 2015, 7:38pm UTC](https://boards.straightdope.com/t/tankless-water-heaters-any-experience-or-advice/713559/33 "2015-02-26T19:38:56Z")
> [@johnpost](#): > > you have 100 A of 220 V. > > not enough. At first I thought you were wrong, since I’ve heard of 100 watt heaters, but they require 67 degree input, and I notice the OP is in Wisconsin. Still, I’m surprised the input water temperature hasn’t been brought up before. ---
**Author:** ![Blue\_Blistering\_Barnacle](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/blue_blistering_barnacle/32/3386_2.png) [@Blue\_Blistering\_Barnacle](https://boards.straightdope.com/u/Blue_Blistering_Barnacle)\ **Post date:** [February 26, 2015, 7:55pm UTC](https://boards.straightdope.com/t/tankless-water-heaters-any-experience-or-advice/713559/34 "2015-02-26T19:55:23Z")
We have an old one that came with our small summer cabin. It works ok, but water temperature “wobbles” as you take a shower. Maybe a function of age. It broke down once- I was able to fix it myelf by swapping out the control board. ---
**Author:** ![The\_Evil\_Prince\_Zorte](https://avatars.discourse-cdn.com/v4/letter/t/e95f7d/32.png) [@The\_Evil\_Prince\_Zorte](https://boards.straightdope.com/u/The_Evil_Prince_Zorte)\ **Post date:** [February 27, 2015, 1:32am UTC](https://boards.straightdope.com/t/tankless-water-heaters-any-experience-or-advice/713559/35 "2015-02-27T01:32:21Z")
I have a gas one, and in summer when water heating is the only significant usage of gas, it cut the bill in half. It does need to run about a gallon of water to get the hot going, and I had to take the flow reducer off of the bathroom faucet. By the time you got the temp from too hot down to lukewarm, it would drop below the minimum flow. Despite those cons, the unlimited supply is great. We have a large tub, and with the tank heater I would have to turn on the hot water only, then when it ran out the resulting cold water would reduce the temperature as it finished filling the tub. ---
**Author:** ![Musicat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/musicat/32/20189_2.png) [@Musicat](https://boards.straightdope.com/u/Musicat)\ **Post date:** [February 27, 2015, 2:08pm UTC](https://boards.straightdope.com/t/tankless-water-heaters-any-experience-or-advice/713559/36 "2015-02-27T14:08:13Z")
> [@Renee](#): > > You’d have to bring in new wires from the street. It’s a major job. The power company brought new wires from the street last year when I had to replace the feed pole into the house (the old one got bent by a falling tree). They didn’t charge anything at all, but of course I paid an electrician to hook everything back up. I think the cost this time would be for a larger service entrance box. > [@](#): > > I know you dismissed the propane option, but if your water heater is on or near an exterior wall, it’s really not a big deal to put a 100lb propane tank outside, and do a direct vent water heater. Nowhere near the $5K you suggested. As a DIY project, I’d estimate about $250 plus the cost of the water heater. The heater location is indeed against an outside wall, but if I put a tank directly outside, it would be a lot uglier than the lake view it would block. I think those tanks are ugly enough no matter where they are. I doubt if local zoning would allow a tank sitting on the beach, and I sure don’t want it on the patio. To be fair, my$5K cost estimate was based on a larger propane tank installation when I was considering converting from fuel oil heat to propane, and lines would have to be run around the side of the house. > [@BigT](#): > > Still, I’m surprised the input water temperature hasn’t been brought up before. It was. > [@Musicat](#): > > My incoming water to the heater will vary from 42F to 65F. The well water comes in to the house at 42F year-round, but sits in a pressure tank in the basement and in the summer, could warm up to 65 max. It looks like I will be going with a 40 gal tank-type electric heater. I found a plumber who will pick up the model I want from Home Depot, 50 miles away, and install it for me, plus removing the old tank. Estimated bottom line, $900 (tank alone, $450). There shouldn’t be any extra electrical work needed. [Previous page](https://boards.straightdope.com/t/tankless-water-heaters-any-experience-or-advice/713559.md?page=1)