View Full Version : Instant Water Heaters
09-01-2004, 07:56 PM
Glad to see your site is back up, Terry. Ol' John Bridge told us over to his place that you had to shut down. Didn't know what I'd find over here. :)
Don't seem to be able to search for information on the old forums from this new one, so I'll just post what is probably a much-answered question:
My customers insist they want an instant hot water heater for a bathroom I'm gonna add to an existing structure rather than a storage-type heater. They travel all over the world a lot and see these things everywhere they go. Everywhere but here in the US of A.
I have no experience with them at all, nor has my regular plumber. I've told the customer that I don't believe we have enough electricity available to operate such a heater that is capable of serving a large bath tub (that will see substantial use) and shower, but I don't know if the truth is with me on that. LP gas is available, but with substantial effort required to get it to that building.
My question is mostly about what brands or styles or sizes I should seek out and which ones I maybe should avoid.
Any help appreciated.
PS: Your site wouldn't allow me to add an avatar to my profile. Like your new format, very user friendly, very familiar. :)
09-01-2004, 08:10 PM
You're right about needing to upgrade the electric in the structure to accommodate an instant electric water heater. Another option would be to install an electric (storage type) tank near the new bathroom, although this may require more juice than there is as well.
Try this link to search the old board for additional info.
09-01-2004, 08:22 PM
I saw that archived site on my way here, but there doesn't appear to be a search feature there.
09-01-2004, 10:01 PM
Ok, I'll paste it back on the page.
These are Bosch gas tankless (http://protankless.com/html/protankless/index.html)water heaters
Powerstream Electric tankless (http://protankless.com/html/whpowerstream/rp27pt.html)water heater
I don't know as much as I'd like, they are getting more common so I will be adding them to my site soon.
I will add them to my shopping cart (http://www.terrylove.com/store/)when I get some time.
It looks like you can go with either the gas or the electric for your situation.
Wiring for the electric can be seen on the pdf file, the one pictured uses three double pole breakers of 240 volts.
09-01-2004, 10:46 PM
Looks like the small electric unit wants 80 amps. I only ran 100 amp service to the building when it was built and it has a two ton heat pump, among other electrical loads, already. That ain't gonna work.
Hafta put a pencil to that gas unit. Lotta ditch to get the Propane to it.
I think they need a nice little storage tank heater. Bet I get some agreement when they see the price tag on making that "really efficient" unit work there. :)
The ones I have seen and used have a "huge" pressure drop in order to slow the water down enough so that it stays in the heater long enough to get hot. An electric one needs about 120 amps for any reasonable capacity. One customer who had a "staged" triple unit complained that one or more were constantly needing to be reset. I have several other issues with them, but will be meeting with a representative in a couple of weeks to see if he can enlighten me about them.
09-02-2004, 07:56 PM
One other significant thing to consider with a tankless system is the maximum rise. Most are only spec'ed to raise the water temp up to 70 degrees. Now, if you live in the tropics, that is more than enough. I have one, and am going to replace it for the following reason: in the late winter time around here (and last year was nasty), the incoming water temp gets around the low 30's. Bump that up 70 degrees, and then run it a ways, and you only get lukewarm. To get that, they put a flow restrictor on the system. Mine, using a 100Kbtu system, can flow 3.5 gallons/minute for the spec'ed temp rise. In the winter, it takes forever to fill a large tub (but you can keep doing it over and over again!).
09-02-2004, 09:52 PM
Appreciate the comments, gentlemen.
The property in question is on a private water well, and I think we run a pretty consistant 55 degrees on the water temprature in this area, so that part shouldn't be a big problem if a 70 degree rise is the norm.
On the downside, one of the major features of this add-on is a very large soaking tub. Might be a problem with a storage heater, too, but sounds like there could be a pretty high level of filling time frustration with the tankless unit.
Can't say as I'm hearing a lot of major advantages being expressed on behalf of these units. :)
09-03-2004, 08:46 AM
I researched them while milking along my tank and Envirotech (http://www.envirotech.com/) seemed like the best one based on research and reviews.
09-03-2004, 11:41 PM
I sometimes wonder if when people insist that they should have a tankless water heater because they have them 'all over the world' except North America if they are perhaps comparing apples and pears.
I think North America is more self indulgent regarding high water consumption luxuries such as hot tubs, soaker tubs etc. Europe for example has to be more prudent with their limited resources. I have a European front loading washing machine and it is amazing how little water it uses. Many European appliances such as Dishwashers and Washing machines have their own on board water heater. My European dishwasher enables me to set the desired temperature and the water will be heated up to that temperature.
Therefore I think a tankless water heater would be fine in my home for example where my hot water requirements are low (almost European). However in the typical North American home with soaker tub, top loading washing machine etc. I think it would be really stretching the capacity of the tankless water heater. You are right about the extra power that would be required. I would also like to get a tankless water heater one day but I know I would need to double my electrical panel (currently 100 amps) . I was thinking perhaps of the water heater having it's own panel. I love the idea of the space that would be saved as well as electricity. Because even though it would use a high amperage of juice while heating water as soon as the tap is turned off it is no longer heating the water. Whereas the tank water heaters heat the water even when you are not using it.
Steve, I think when I finally do go for the tankless water heater that I would be choosing the Envirotech tankless water heater.
Everything in Europe and Britain is smaller, because their apartment and housing units have smaller areas which means dishwashers, clothes washers, and water heaters have to take up as little space as possible, therefore, a small tankless is ideal in that environment.
09-04-2004, 10:09 PM
Well, I'm not sure where I got the 55 degree well water temprature I was advertising. I went to the site and measured the water temp coming right out of the well and it was about 70 degrees.
Looking at the data on the Envirotech site, it still looks like 60 amps service would still be the minimum, and 80 would be better. I'm basing that on their 3 gpm specs. Is that a reasonable flow rate for a single bathroom?
09-05-2004, 05:52 PM
3gpm isn't that much. Enough for one appliance - most showerheads are restricted to 2.5gpm, but that is at "normal" pressures, which you won't have with the required flow restrictor. If you ever wash clothes in hot, it can take 45g - 15 minutes to fill. A tub can take anywhere from around 30 to 60 or more gallons to fill - is ten minutes okay to fill for you?
If someone else opens the hot water line while you're taking a shower, it will drop to a trickle. don't try to wash dishes or laundry while you are taking a shower! If none of these are concerns, then you may be okay.
Also, read the specs carefully. They sometimes only get the stated temp rise at lower than max flows. Unless you have a really shallow well, and live in the tropics, or have a geothermal heat source! Maybe in the middle of the summer most places, but still, I wonder. You have to run the water a long time to empty the storage/pressure tank to get a good incoming reading. Now, if you have a big pressure tank in a heated room, then that would really help until you dilute it with actual fresh well water.
I lived in Kuwait for awhile. They had water storage tanks on the roof. In the summer, the cold water was too hot to shower in. We turned off the hot water heater, and used that for cold. God help you if you ran out of "cold" water in the hot water tank - hot mixed with hot!
09-19-2004, 10:13 PM
Once again, thanks all for the information. :)
No final decision at this point. I may have swayed them a little by tellin' them I could install three 50 gal electric tank heaters for less than it will cost for one tankless model in this situation (especially with the new gas line), and that it is really no trouble at all to install a switch so they can turn off the electric to the heater when they're fixin' to be outa town for a couple weeks (frequent occurrence).
Or maybe I'll get to install my first tankless. Quien sabe? But I've added a little more plumbing knowledge to the ol' data base. :)
09-20-2004, 05:24 PM
The Tankless water heater - http://titanheater.com - I have used in my home has worked great. it was recommended to me by a friend who was using one himself.
At first, I was apprehensive about using it. However, based on many testimonials, personal and online, I went ahead and purchased the Titan SCR2.
My home is a two story single family 4-bd, 3-ba. We have never had an instance where hot water was scarce. On the contrary, we have to be careful not get the water too hot! It's scalding.
The price is very reasonable, and outperforms many heaters costing double the price or more. Installation went smoothly. I'm quite handy around the house, so I did all of the work, EXCEPT the electrical. I started by removing the old (30gal tank) heater. I did the soldering for the copper tubing and added a ball valve (there wasn't one) to the incoming water for future convinience. The one thing you have to be careful about is not to apply heat to the tubes connected directly to the unit. The next day the electrician did the wiring and the tankless heater was running.
TitanHeater.com provided great service and quick delivery. They have the Titan SCR2 in different capacity models, but I got the N-120, which is their largest. The prices are affordable and they offer free shipping at times.
All in all, I have to say I'm very happy with the new tankless heater. And the kids like showering once again too! :)