Anyone ever have experience with an EEMAX tankless water heater. Looked at one the other day. UL Listed. The heating element is a BARE nichrome coil IN the water stream!! Available in voltages up to 277 single phase and 480/277 three phase as far as I know. Any thoughts about having bare energized conductors in domestic water piping??

jes,
There shouldn't really be any problem with this type of system, as long as the whole Hot Water system is Earthed properly.
There is also the Electrode-Boiler system,
that uses the Electrical resistance of the water itself, to heat the water, this also uses bare, live "elements", in contact with the water.
Hope this helps.

Electrode boilers were once fairly common in the U.K. for commercial use. The big 3-phase ones could run on 440V.

Personally, I've never been quite happy with the concept......

I'll agree with Paul — 1 megawatt+, 480V electrode boilers in industrial applications aren't that tough to find.

I don’t know if it's a requirement, but those I've come across in plants have used a dedicated secondary-unit substation with a medium-voltage-primary transformer.

Industrial applications adide, I'm talking RESIDENTIAL here...say hooked up to your sink or shower!!

Conventional elec. water heaters with a blown heating element can cause all kinds of tingles when the system is poorly grounded/bonded.

For residential, I definitely don't like the idea, especially for feeding a tub or shower.

I know this type of tankless heaters with nichrome coils are common in some countries. Does anybody know how the "power showers" which are rather popular in the UK and Germany works?

I had a look at EEMAX homepage and in my always humble opinion, it appears like a low-cost alternative but if UL has approved it, it can't be blatantly unsafe, can it?

(I looked at the models on the Norway site and noticed that for the 40 Amp heater a 25A breaker and 4mm2 (#12) cable is the recommended minimum. A bit tight, in my humble opinion)

Test

Those units (I call them demand units because they just warm the water on demand) are very popular in Puerto Rico and other parts of the carribean where homes don't need heat and don't have hot water tanks as a rule.
The most common unit is right in the shower head and cord & plug connected. It's just plugged into the outlet in the bathroom. BTW most of the bathroom outlets I've seen in that region are not GFCI protected.
OSHA Professor
Grizzy

jes,
What I forgot to say, was that these things, over here in NZ, no matter what size, are invariably fed via some sort of Earth-Leakage protection, normally 30mA for ordinary personal protection, 10mA for Hospitals and other Medical areas.
These types of heaters are becoming more common for use,over here as shower water heaters instead of using the traditional Hot water Cylinder, I hate the damned things,
they are such a nuisance to wire.

Hey guys, i just wired one of those tankless heaters 2 weeks a go in a new home! A 125 amp sub feed ! This heater came with its own panelboard and breakers. 4 30A breakers,and each circuit i think was about 22A. Sorry i do not recall the brand.

One of the Architects I work with like EEMAX and so we have them installed in several locations. I have not been informed of any problems yet. Some other brands of instantaneous water heaters I have heard complaints about, but they have been "the water is cold still".

You have peaked my interest and I will watch them a bit closer.

Shane

The "flash heaters" that Grizzy The OSHA Per-fesser has described are also big in parts Peru, that tend to be cold but people don't want to spring for a real boiler.

In Colombia, if you want hot water you buy a real hot water heater (tall tank or a short large kettle connected to electricty -- usually 220 volts hot-hot) just like in the USA. Town-gas models are also for sale now that town-gas use is getting popular.

In fact, cosmetically they look the same. However there are some locally-made brands (Haceb and Icasa are the two major national manufacturers) and imported models. However, flash heaters (calentadores de paso) are also available for people who live in apartments or don't have the ability to use a normal heater.

Here in New York, the local Quiznos hot sandwich shop around the block from my office has a flash heater connected to the bathroom sink. It's powered off a 220 volt hot-hot socket underneath the sink (not GFCI protected at the outlet, maybe at the breaker box?).

The damned thing doesn't work! It's bull! You run the water, the light on the little plastic box turns on....but the water is still ice cold in the winter (and cold in the summer)!!!!!! I'm starting to think it's just a box with a lightbulb.

Isn't there a health code that says you must have hot water in your restaurant bathroom?

[This message has been edited by SvenNYC (edited 02-20-2003).]

The major problem with these "instant" showers and water heaters is that the element heats the water THRU a certain temperature range rather than TO a specific temperature.

The temperature of the emerging water depends upon:
(a) the temperature at which the cold water enters
(b) the power of the element (naturally!), and
(c) the rate of flow.

Given that you have no control over the first two variables once a system is installed, the only way to increase the water temperature is to reduce the flow rate. Some people have gone with underpoowered units here only to discover that to get anything like even lukewarm water in winter they have to reduce the flow to little more than a dribble.