Tankless - My plumbing supply house pooh-poohed them?

[DansParts]

A whole-house tankless heater would offer me several distinct advantages in my house.  The most important would be the room it would free (eliminating the big tank), so I could re-invent the laundry/entryway room into something that would actually work.  As opposed to the current configuration, which doesn't even allow me room to put in a newer model washer/dryer (most of which are wider than the ancient ones we have), without stacking them - something I don't care for.

So, I read all the posts on here I could find to see what all was recommended, and found not very much in the way of recommendations.

I did see a couple things that I'm keeping in mind, like difficulty in obtaining repair parts on models bought from big box stores (in other words - go to a "real" place to buy plumbing stuff!!).

One thing that may make a difference in all this is that I have an all-electric house, so the tankless would have to be electric.

So, my next step was to ask at my plumbing supply house when I went there to buy parts for a drain renovation project I was doing.  While not in the exact words, the guy there pretty much said, "You don't really want to put one of those in, do you?"  Implication, of course, was that I wouldn't be happy with it, and they use WAY too much electricity.  He did quote me a price on the only unit they carry - a Bosch - at what seemed to be a fairly reasonable figure.  I don't know if he was reacting out of personal preference/experience, or something else when he made those comments.

I did check the other plumbing supply house in town (this one the counter looks like they're still in the 1940's, which makes ME feel comfortable, since I'm old, too [just ask my wife...]), and they refuse to carry them.  Too hard to get parts, they said.

So, next I inquired of people I knew, and found that my son's in-laws put in a whole-house one in their house, and they absolutely LOVE IT!  However, this is a fairly new house, 3 yrs old max, and may not have had time to develop any problems that need remedying.  And, it is gas.

At other sites, I see dire warnings regarding scale build-up, and need for removal/regular cleaning, which worries me a little because of our very hard well water (even though run through softener).

So, to that subject, I remember seeing postings about those electric "softeners" that rely on wires wound around the pipes, which theoretically should reduce that scale to let it simply pass through without collecting.  There seems to be no middle ground on those - they are either "snake oil" worthless devices, or they work just great!  Even though there are probably shills or people with a particular axe to grind against the opposite technology posting on some sites, most of the postings at least seem to be genuine.  But, they are about evenly divided about yea/nay on the subject.

So, my questions here are:
Why would you, or would you not recommend a tankless (whole-house)?
Does it make a difference for you to recommend a tankless if it is gas-fired or electric?
What about scale build-up?  Is removal or preventative the best method to keep heater in good condition?
Recommendations as to brands (in reference to obtaining repair parts)?

Thanks for the help.

[electro_doc]

I have a Stiebel Eltron, DHC instantaneous Water Heater.  Pretty sure it's a model 10-2.  I love it.  It is all copper and I've had it for 3 years  with no problems.  I've had it all apart to clean an internal screen that got restricted with sediment.  That is the only flaw I've found.  The next model up has a screen you can clean on the outside so you don't have to take it apart.  I've found no sediment on the heater or tubing and I live in Costa Rica where everything corrodes really fast.  I would recommend the copper.  This one is from Germany and is really well made.  It does use a lot of electricity but it's only on when you use it.  I have found it to be about the same as my old water heater in total kilowatts used.  They have a representative down here and really good service and a 3 year warranty.  I have gone to them for parts to fix other peoples that were out of warranty.  So far only replaced a high limit thermostat and some wire connections burnt due to bad connection.  I would check in your area for a good German made one or at least one with copper tubing inside.  Also check for a service rep in your area.  Other than that I'm very happy with mine.

 

 

Doc

[DADoESTX]

I have a whole-house electric tankless, 9 years old.  I didn't choose it, it was in the (new) house I bought.  I was leery of it but have found that I like it.

 

I won't cite the brand as the manufacturer is long out-of-business.  Had two problems with it.  1) A tiny leak on a fitting (not quite tight enough) at the outflow port caused a wire to corrode after several years.  2)  The incoming flow sensor went bad due to the unit not having been de-limed in 6 years (at the time, I do it yearly now, I'm on well-water and do not have a softener).  I did find a replacement part.

 

Retrofitting a tankless to an existing tank system can involve other required service upgrades.  A whole-house tankless may pull a very large energy-flow (gas or electric) when operating so the electric service or gas service drop to the house may have to be upgraded.  My unit pulls 120 amps (28,800 watts, four 7,200-watt elements) at full capacity.  That rarely happens in my case (your usage patterns may be different) but the circuit must be able to meet the maximum requirement.

 

A trick to getting satisfactory performance and most economical operation is to not overheat the water.  A tank unit must maintain a standing supply of water heated to a higher temp than is needed so as to have reserve capacity, otherwise you'll run out of heated water on that 30-minute luxury shower, or even a 10-minute shower if the washing machine, dishwasher, and/or another bath are running at the same time or a few minutes prior.  A tankless unit can produce heated water all day long without running out so there's no need to overheat for reserve capacity.  If 105°F is comfortable for a shower, set it at 105°F and run only the hot tap (no cold mixed-in).

 

To be sure, tankless units will moderate the energy usage in response to varying water flow rates to maintain the target temp (within the capacity limits) ... so running 140°F water slower (with some cold mixed-in at the tap) will give pretty much the same energy consumption as running 105°F water faster.  But, tankless units have a minimum required flow rate to activate and stay activated.  Cutting the 140°F flow rate too much, the unit will shut off completely, causing a COLD shower, which triggers the bather to crank up the hot tap ... then the tap is cut down again ... cold shower again.  Ping-pong.  Running a moderate temp at a faster rate (only the hot tap for a shower, unit set AT the desired temp, NO cold mixed-in) will insure the flow-rate stays high enough and the unit doesn't shut-off mid-shower.  I understood from the start how to make best use of the unit, never have had that occur.

 

Remote controls are common nowadays, mount one in the bathroom(s) for ease of adjustment.

[Cactus Bob]

"My plumbing supply house pooh-poohed them" And so do I  .  for the amount extra they cost , the problems they have , i do not recommend them .

A tank style water heater is safe and long lasting . Provides a 30-50 gallon source of clean drinking water if or when your water supply get interrupted .

 

A tankless is none of the above

[DansParts]

Cactus Bob -

 

Thanks for your reply.  I know they're more expensive, but have I overlooked other problems with them?

 

Thanks.

[Patricio]

Cactus Bob, good to hear from you again.  I have missed your professional input.  Had a lot of heater repairs over this cold, wet winter that has kept you busy?

[Cactus Bob]

DansParts : the problems i have seen mostly come from electronics in the heater , sensors are second . the electric ones need two 240v supplies and are expensive to install, if there not going to be close to the breaker box

 

I used to like the old ones from the 70's , these had no electronics and where triggered by a drop in temp of the inlet water . these kept the water in the heater a little warm all the time and turned on 4 water heater elements to quickly heat the water as it ran through the unit .these where great , lasted for years and only needed replacement of elements once in a while

 

Not so with the new ones . these can freeze if installed in an unheated room . water leaks and the need to sometimes run water a long time to trigger the unit on and heating

these units may not heat when using a low flow shower head , in this case you may need to run the sink water when showering to get hot water

 

All in all most plumbers that are not selling them , hate them

[Cactus Bob]

Patricio: I am in Arizona so we really do not have winter here . but we do have Snowbirds and collage apartments that keep us busy all winter long .

It was 70+ degrees almost every day this winter , so AC demand was high and so where breakdowns

this was a banner year , the old farts came and brought us a lot of money and the collage apartments landlords did too .

Best year in years !!

Now we take a break for a month until we hit summer , then it's off to the races again . we hope . 

 

I hope this winter was as good for you as it was for us , best wishes

Edited April 5, 2014 by Cactus Bob

[DansParts]

Cactus Bob -

 

Hmmm.  That's something to consider, and just exactly why I came back here - to get advice from people with experience.

 

While a couple of the problems you mentioned won't be a problem here (it's to be installed about 2 feet from the breaker box in a heated room), one thing you mentioned does bring up old memories.  My softener had problems with the electronics, which was an expensive waste of money.

 

When you say water leaks, do you mean internal leaks, like from possibly defective assembly of the unit at the factory?  Or the plumbing attachments to the units?

 

Too bad I couldn't buy one of those heaters from back in the 70's, but I imagine there's not a chance of that happening.

 

I still haven't gotten around to checking the water flow everywhere in the house, but I don't think that will be a problem either.

 

Still, I'm not as sure as before.

 

I'll have to decide whether the benefits will outweigh the [potential] drawbacks.

 

I'd appreciate also hearing from anyone else on this subject.

 

 

Dan

[micabay]

If you own a dishwasher, I wouldn't recommend going tankless...  Most dishwashers don't fill at a fast enough rate to trigger the heater.  Then it fills with cold water.  Filling dishwashers with cold water isn't recommended by most manufactures.  Also, on some designs of dishwashers, it will lock you out if it takes too long for the water to reach the proper temp.  The heating element helps, but isn't always good enough to get the water up to temp.

[J5*]

If you own a dishwasher, I wouldn't recommend going tankless...  Most dishwashers don't fill at a fast enough rate to trigger the heater.  Then it fills with cold water.  Filling dishwashers with cold water isn't recommended by most manufactures.  Also, on some designs of dishwashers, it will lock you out if it takes too long for the water to reach the proper temp.  The heating element helps, but isn't always good enough to get the water up to temp.

 

 

most dishwashers fill with cold water

[micabay]

most dishwashers fill with cold water

False. I've yet come acrossed one that wasn't only hooked up to hot water. If you don't run the water at the sink untill hot and fill the dishwasher with hot water, you will have long term wash ability problems. Why would the manufacture require the machine hooked up to hot water if it didn't want you to fill with hot water?

[sh2sh2]

False. I've yet come acrossed one that wasn't only hooked up to hot water. If you don't run the water at the sink untill hot and fill the dishwasher with hot water, you will have long term wash ability problems. Why would the manufacture require the machine hooked up to hot water if it didn't want you to fill with hot water?

J5's profile says he lives in non us or canada, i guess elsewhere dishwashers fill with cold water

[micabay]

J5's profile says he lives in non us or canada, i guess elsewhere dishwashers fill with cold water

Well sheet. That changes everything. If it wasn't for the USA and our "eco friendly" "engery efficient" appliance regulations, you could indeed design and build a good machine that didn't require being hooked up to hot water. I sometimes forget, not everyone on the interwebs resides in the States.

[DADoESTX]

There are a few "foreign" dishwashers available on the US market that can work on a cold connection.

[J5*]

Well sheet. That changes everything. If it wasn't for the USA and our "eco friendly" "engery efficient" appliance regulations, you could indeed design and build a good machine that didn't require being hooked up to hot water. I sometimes forget, not everyone on the interwebs resides in the States.

 

down here in the land downunder most if not all dishwashers on the market cold fill

 

cold fill because proteins bake on when hit with hot

 

we used to have some which had hot and cold fill so depending on what part of the cycle it could take hot water but as you already pointed out it takes time to get the hot anywhere

 

if you have solar hot water then you would want to take advantage of hot water

 

we have goverment testing and energy ratings and i recall a few years ago seeing ratings for both cold and hot fill and the energy consumption of hot fills was higher due to i guess taking into account the cost to heat the water heater  of the house

 

we dont have long term wash issues here where i live, and that is prob because we have pretty good water , but in other places of the country there is varying water and funny eough when i have gone to work in different parts i saw different problems in washing machines that i can only put down to water quality

 

but back to the original question , if the local plumbing places advise against the tankless then why not heed the advice ?

Edited April 11, 2014 by J5

[telefunkenu47]

Okay, so the power company burn oil or gas or whatever at approximately 70 percent efficiency, so assuming oil at 115.000 btus in a gallon of oi,l less 30 percent is 80,000 btus give or take. Now they send it down 8 million miles of power line losing oh, I don't know, 10 percent line loss, so now we are down to 72,450 btus for the 115,000 you had to pay for. So, now we sell it to you at a profit after figuring in cost etc, I would estimate that you just paid around 7 dollars a gallon for the 115,000 btus  you would have gotten if you had just burned the oil, propane or natty gas right in your home in an ultra modern high tech new fangled 85 plus demand water heater like the rinnai continuum or even a halfway decent tank type heater taking up precious space in the utility room of your home. Electric demand heaters just plain suck for all of the reasons listed above, unless you live next door to a nuc-you-ler power plant. Just sayin...

[Hiroshi]

I have an on-demand water heater, but it is gas operated. Except for hearing the burner ignite when you turn the "hot" handle, it has been quiet, reliable, and heats the water as hot as I have ever wanted it. It can run the washer and dishwasher simultaneously, but mind you, I only like the gas one- I had an electric version in a condo and hated it as it never gave hot enough water fast enough- even on the highest temp setting. During the winter, FORGET ABOUT IT! The electric model couldn't heat the colder incoming water well at all...

[jay jay]

Down here in central america, you will see only on-demand units.  Most are inexpensive (cheap) units.  Either gas or electric under $300

Gas is more economical.  But there is only LP gas here, so you have a tank.  100# is $50 USD

Electricity is about $0.17 / kwh

The electric ones do fail mostly because of power problems.  Spikes and such.  When they work, they are fine, but the watthour meter gets a workout.  Check the wattage ratings and calculate the amperage.  Yikes.

The gas ones are no-name brands.  Cookie-cutter units from china.  So when a small part fails, there are no replacement parts.

They are NOT like a tank style heater.  It is a controlled boiler.  The operation needs to be explained to the customer, otherwise you will get call-backs.  Most often it is when Mr customer turns the heat (flame size) up, then complains that the water heater goes cold when in the shower.  Then the teacher has to explain about the boiler and that is shuts off with low flow.  By turning up the flame, now you had to turn on the cold water and the shower flow was divided between hot and cold ..... I then get the Ah Ha !!

Jay