# tankless water heaters - what do you think? **URL:** \ **Category:** In My Humble Opinion\ **Created:** [November 25, 2014, 4:07pm UTC](https://boards.straightdope.com/t/tankless-water-heaters-what-do-you-think/705602 "2014-11-25T16:07:37Z")\ **Posts on this page:** 19\ **Page:** 4
**Author:** ![blood63](https://avatars.discourse-cdn.com/v4/letter/b/97f17d/32.png) [@blood63](https://boards.straightdope.com/u/blood63)\ **Post date:** [November 26, 2014, 6:34pm UTC](https://boards.straightdope.com/t/tankless-water-heaters-what-do-you-think/705602/61 "2014-11-26T18:34:18Z")
Also, this tankless system has a sediment component that allows you to remove sediment from hard water before they build up. ---
**Author:** ![Waterman](https://avatars.discourse-cdn.com/v4/letter/w/b2d939/32.png) [@Waterman](https://boards.straightdope.com/u/Waterman)\ **Post date:** [November 26, 2014, 8:22pm UTC](https://boards.straightdope.com/t/tankless-water-heaters-what-do-you-think/705602/62 "2014-11-26T20:22:12Z")
> [@Habeed](#): > > Actually, it’s 54%+ : Google for “[combined cycle](http://en.wikipedia.org/wiki/Combined_cycle)” on wikipedia. > > Essentially, you can either burn the natural gas in a tankless heater for about 50-60% efficiency, or you can burn it in the power station at about 55% efficiency then lose about 10% sending it over the transmission line and lose another 5% in the electric tankless heater itself. Natural gas delivery lines leak a little and have higher costs to transfer energy than electric wires. > > TLDR, it’s very close in terms of real overall efficiency, and the higher upfront cost of buying and installing a natural gas tankless heater means the electric ones may be a better choice. > > Not to mention, it’s probably a better idea to plumb a house with 3 or so small tankless heaters (such as 1 for master bath, one for second bathroom, one for kitchen/laundry) which means there is some redundancy in the hot water supply and the delay for hot water when turning on the spigot is minimal. Very few generating stations in the US are combined cycle. Most are conventional steam electric stations whether they use oil, coal or natural gas as the fuel. ---
**Author:** ![Waterman](https://avatars.discourse-cdn.com/v4/letter/w/b2d939/32.png) [@Waterman](https://boards.straightdope.com/u/Waterman)\ **Post date:** [November 26, 2014, 8:26pm UTC](https://boards.straightdope.com/t/tankless-water-heaters-what-do-you-think/705602/63 "2014-11-26T20:26:50Z")
> [@blood63](#): > > Yes, if my loan were $5000 but my loan is not. Clearly the company wants me to buy into their 10% payment plan because they said nothing about an up front cost. > Their plan is $44 a month for 120 months. The total after 10 years is 44x120 or about $5000. Can anyone calculate the actual 2014 cost of equipment and installation from this? Unless I’m missing something in your posts, there are still two unknowns: the principle of the loan and the interest rate. Need to know the interest rate to calculate the principle which would be the cost of the heater plus installation. ---
**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:** [November 26, 2014, 8:36pm UTC](https://boards.straightdope.com/t/tankless-water-heaters-what-do-you-think/705602/64 "2014-11-26T20:36:44Z")
The OP said that the interest rate is 10%. ---
**Author:** ![Bill\_Door](https://avatars.discourse-cdn.com/v4/letter/b/50afbb/32.png) [@Bill\_Door](https://boards.straightdope.com/u/Bill_Door)\ **Post date:** [November 27, 2014, 1:26am UTC](https://boards.straightdope.com/t/tankless-water-heaters-what-do-you-think/705602/65 "2014-11-27T01:26:26Z")
> [@blood63](#): > > Yes, if my loan were $5000 but my loan is not. Clearly the company wants me to buy into their 10% payment plan because they said nothing about an up front cost. > Their plan is $44 a month for 120 months. The total after 10 years is 44x120 or about $5000. Can anyone calculate the actual 2014 cost of equipment and installation from this? Sorry, I misunderstood your OP. At 10% interest for 10 years a $3,325 loan would cost $43.94 a month. Still a crazy high cost and you’ll never see a profit. It’s a rip off from day one. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [November 27, 2014, 1:31am UTC](https://boards.straightdope.com/t/tankless-water-heaters-what-do-you-think/705602/66 "2014-11-27T01:31:03Z")
Since the OP is looking for opinions, let’s move this to IMHO. Colibri General Questions Moderator ---
**Author:** ![Melbourne](https://avatars.discourse-cdn.com/v4/letter/m/b5e925/32.png) [@Melbourne](https://boards.straightdope.com/u/Melbourne)\ **Post date:** [November 27, 2014, 2:10am UTC](https://boards.straightdope.com/t/tankless-water-heaters-what-do-you-think/705602/67 "2014-11-27T02:10:40Z")
> [@Caffeine.addict](#): > > I replaced the water heater in my old house because it was 14 years old and I figured it was time to change it out. > [@blood63](#): > > I wonder if anyone has any insight into how long my current water heater should last if it is 10 years old now. They service agent gave me some scary scenarios that it might burst etc. > [@Leaffan](#): > > I’ve been in my house for 19 years and am on the third water heater, mind you it’s electric. I seem to recall that 7 years is the average age. > [@I.Dunno](#): > > My gas water heater is 15 years old and working fine. I replaced it myself when the old one started leaking water onto the basement floor. It was a small leak and I let it go about 2 weeks until I got around to replacing it. An old water heater is not likely to suddenly burst apart. Around here, tanks have a long thin Sacrificial Anode. You should have that replaced about every 7 years, because it sacrificially corrodes away, protecting your tank. Most people (around here) don’t replace the sacrificial anode, which means that after about 15 years the tank leaks, and needs replacement. ---
**Author:** ![jacobsta811](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jacobsta811/32/2893_2.png) [@jacobsta811](https://boards.straightdope.com/u/jacobsta811)\ **Post date:** [November 27, 2014, 6:43pm UTC](https://boards.straightdope.com/t/tankless-water-heaters-what-do-you-think/705602/68 "2014-11-27T18:43:26Z")
> [@Melbourne](#): > > Around here, tanks have a long thin Sacrificial Anode. You should have that replaced about every 7 years, because it sacrificially corrodes away, protecting your tank. > … You ever try to get one of those out ? I read about that on the internet and tried on my water heater when it was about that old. An air impact wrench at 150 PSI didn’t move it, neither did a 2 ft long breaker bar on the socket wrench or a hammer. Finally just gave up and have the new bar sitting around somewhere. Edit to add, have since replaced the water heater, but it lasted another 5 years after that. ---
**Author:** ![Suburban\_Plankton](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/suburban_plankton/32/219_2.png) [@Suburban\_Plankton](https://boards.straightdope.com/u/Suburban_Plankton)\ **Post date:** [November 27, 2014, 9:01pm UTC](https://boards.straightdope.com/t/tankless-water-heaters-what-do-you-think/705602/69 "2014-11-27T21:01:27Z")
We had a clogged pipe a while back, and had to call a plumber out to fix it. I noticed on his website that he was a dealer for a particular brand of tankless water heater, and since we haven’t replaced our water heater since we bought the house 20 years ago I asked him about it. He told me: a) due to the way our house was laid out, a tankless heater wouldn’t deliver hot water much faster than our traditional heater b) given the amount of water we use, it would probably take at least a decade to recoup the extra expense c) after examining our existing heater, despite it being 20+ years old, there was no reason to replace it at this time. He gave me a ballpark estimate of $1200 for purchase and installation of a new water heater, including some modifications to the existing plumbing to meet new codes…when it becomes necessary. ---
**Author:** ![MacSpon](https://avatars.discourse-cdn.com/v4/letter/m/34f0e0/32.png) [@MacSpon](https://boards.straightdope.com/u/MacSpon)\ **Post date:** [November 27, 2014, 10:52pm UTC](https://boards.straightdope.com/t/tankless-water-heaters-what-do-you-think/705602/70 "2014-11-27T22:52:59Z")
A year ago, I moved from a house with a tank, to a house in the same area but with a Rinnai instant (tankless) heater. My combined power/gas bill dropped by about 30%. I _love_ mine. ---
**Author:** ![usedtobe](https://avatars.discourse-cdn.com/v4/letter/u/ec9cab/32.png) [@usedtobe](https://boards.straightdope.com/u/usedtobe)\ **Post date:** [November 29, 2014, 8:41am UTC](https://boards.straightdope.com/t/tankless-water-heaters-what-do-you-think/705602/71 "2014-11-29T08:41:09Z")
> [@jacobsta811](#): > > You ever try to get one of those out ? I read about that on the internet and tried on my water heater when it was about that old. An air impact wrench at 150 PSI didn’t move it, neither did a 2 ft long breaker bar on the socket wrench or a hammer. Finally just gave up and have the new bar sitting around somewhere. Edit to add, have since replaced the water heater, but it lasted another 5 years after that. After all that: Did you remove the anode from the new heater and wrap the threads with teflon tape? Apply anti-seize compound? ---
**Author:** ![ZenBeam](https://avatars.discourse-cdn.com/v4/letter/z/3ab097/32.png) [@ZenBeam](https://boards.straightdope.com/u/ZenBeam)\ **Post date:** [November 29, 2014, 2:06pm UTC](https://boards.straightdope.com/t/tankless-water-heaters-what-do-you-think/705602/72 "2014-11-29T14:06:56Z")
> [@usedtobe](#): > > After all that: > Did you remove the anode from the new heater and wrap the threads with teflon tape? Apply anti-seize compound? If you do this, wouldn’t you need to somehow ensure an electrical connection between the anode and the rest of the heater? You’re essentially trying to make a battery, and an open circuit would impede that. (I just checked mine, and there _is_ some white stuff near the threads, but it might just be corrosion of some kind.) ---
**Author:** ![RickJay](https://avatars.discourse-cdn.com/v4/letter/r/bb73d2/32.png) [@RickJay](https://boards.straightdope.com/u/RickJay)\ **Post date:** [November 29, 2014, 2:18pm UTC](https://boards.straightdope.com/t/tankless-water-heaters-what-do-you-think/705602/73 "2014-11-29T14:18:34Z")
\*\*Never, never, never, never, never, never, never, never do business with someone who comes to your door about water heaters or furnaces. \*\* Allow me to say it again: \*\*Never, never, never, never, never, never, never, never do business with someone who comes to your door about water heaters or furnaces. \*\* There are two kinds of people who sell water heaters door-to-door; scam artists and thieves. There are no other kinds. I don’t care what kind of deal he was offering (and this deal was an outrageous scam; you could buy three water heaters for that) or if he offered a pot of gold with it. If a person comes to your door talking about water heaters or asking to see your utility bills, order them to leave your property immediately. NEVER give them the time of day. ---
**Author:** ![Waterman](https://avatars.discourse-cdn.com/v4/letter/w/b2d939/32.png) [@Waterman](https://boards.straightdope.com/u/Waterman)\ **Post date:** [November 30, 2014, 4:19am UTC](https://boards.straightdope.com/t/tankless-water-heaters-what-do-you-think/705602/74 "2014-11-30T04:19:22Z")
> [@RickJay](#): > > \*\*Never, never, never, never, never, never, never, never do business with someone who comes to your door about water heaters or furnaces. \*\* > > Allow me to say it again: > > \*\*Never, never, never, never, never, never, never, never do business with someone who comes to your door about water heaters or furnaces. \*\* > > There are two kinds of people who sell water heaters door-to-door; scam artists and thieves. There are no other kinds. I don’t care what kind of deal he was offering (and this deal was an outrageous scam; you could buy three water heaters for that) or if he offered a pot of gold with it. > > If a person comes to your door talking about water heaters or asking to see your utility bills, order them to leave your property immediately. NEVER give them the time of day. Having once embarked on selling water softeners (which also needs to be added to **RickJay** ’s list) door to door I can wholeheartedly endorse your opinions! ---
**Author:** ![usedtobe](https://avatars.discourse-cdn.com/v4/letter/u/ec9cab/32.png) [@usedtobe](https://boards.straightdope.com/u/usedtobe)\ **Post date:** [November 30, 2014, 6:47am UTC](https://boards.straightdope.com/t/tankless-water-heaters-what-do-you-think/705602/75 "2014-11-30T06:47:38Z")
Out of curiosity: What IS the “I just need to see your utility bill to save you TONS of money” scam about? ---
**Author:** ![usedtobe](https://avatars.discourse-cdn.com/v4/letter/u/ec9cab/32.png) [@usedtobe](https://boards.straightdope.com/u/usedtobe)\ **Post date:** [November 30, 2014, 6:50am UTC](https://boards.straightdope.com/t/tankless-water-heaters-what-do-you-think/705602/76 "2014-11-30T06:50:41Z")
> [@ZenBeam](#): > > If you do this, wouldn’t you need to somehow ensure an electrical connection between the anode and the rest of the heater? You’re essentially trying to make a battery, and an open circuit would impede that. > > (I just checked mine, and there _is_ some white stuff near the threads, but it might just be corrosion of some kind.) You need very little area for the electrical contact, but good catch. Anti-seize compounds (generally used on engines, in my experience) are copper compounds, to avoid the problem entirely. ---
**Author:** ![usedtobe](https://avatars.discourse-cdn.com/v4/letter/u/ec9cab/32.png) [@usedtobe](https://boards.straightdope.com/u/usedtobe)\ **Post date:** [November 30, 2014, 6:59am UTC](https://boards.straightdope.com/t/tankless-water-heaters-what-do-you-think/705602/77 "2014-11-30T06:59:21Z")
> [@usedtobe](#): > > Out of curiosity: > > What IS the “I just need to see your utility bill to save you TONS of money” scam about? nm - they get the account number and switch your provider to some rip-off supplier. Presumably, my signature would be required to “lock in” the low-low rate. ---
**Author:** ![Really\_Not\_All\_That\_Bright](https://avatars.discourse-cdn.com/v4/letter/r/e8c25b/32.png) [@Really\_Not\_All\_That\_Bright](https://boards.straightdope.com/u/Really_Not_All_That_Bright)\ **Post date:** [November 30, 2014, 11:54pm UTC](https://boards.straightdope.com/t/tankless-water-heaters-what-do-you-think/705602/78 "2014-11-30T23:54:37Z")
> [@Waterman](#): > > Having once embarked on selling water softeners (which also needs to be added to **RickJay** ’s list) door to door I can wholeheartedly endorse your opinions! So were you a scam artist or a thief? 😃 ---
**Author:** ![Waterman](https://avatars.discourse-cdn.com/v4/letter/w/b2d939/32.png) [@Waterman](https://boards.straightdope.com/u/Waterman)\ **Post date:** [December 1, 2014, 7:48am UTC](https://boards.straightdope.com/t/tankless-water-heaters-what-do-you-think/705602/79 "2014-12-01T07:48:11Z")
> [@Really\_Not\_All\_That\_Bright](#): > > So were you a scam artist or a thief? 😃 A poor college student trying to pick up some extra money in a town blessed with incredibly hard water. A fellow fraternity brother and I established an agreement with a local plumber (for a fixed fee) to install the softeners for a “complete package” system. We did go door to door but that was our best way of contacting people in the late 60’s. We made a pretty hefty markup but we really didn’t scam anyone. [Previous page](https://boards.straightdope.com/t/tankless-water-heaters-what-do-you-think/705602.md?page=3)