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Water Heaters - Small Instantaneous Units


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Has anyone bought and installed one of the subject units (usually screwed to the wall by the shower)? Now that the weather has changed cold shower water plays h3ll with my low discomfort/pain threshold. As everyone is aware tutsi is big and bad but I have to admit that I am a puss when it comes to bathing in water that is significantly below ambient bathroom temperature.

My water supply is off town mains and I get excellent pressure after 10pm so that overcoming the dp across a small heating unit would not be a problem in my upstairs bathroom...I would also install a bypass arrangement when heating is not required. Also can anyone discuss the wiring arrangement required for this type of heater?

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Interesting that you should mention this. I have seem the BARE 2 wires stubbed out before next to the shower head without the units installed.

Talk about an area that should be grounded!!! If I could I would have a separate

GFI breaker or at least set up a GFI recepticle to plug the unit into.

Actually knowing what I do now about Thai wiring. I would make everything GFI if I could.

Again no can do without three wire grounded system. There is the possibility of grounding to the recepticle box if it's all metal with metal conduit. It can make a ground but it's not a "true" ground.

If your systen is not three wired it's kind of a mute point.

It's always bothered me, adjusting these heaters when I've been in the shower. I guess was just not my time to die... :o

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TUTSI;; Nuthin to it my friend,I got em all over the house,even in the kitchen so we do our dishes in hot water[ no hepa for us] coarse I already had it.

Figure where ya gonna put it, then get it and you will have a drill template,drill the holes and mount it [you will pobly get the screws and plastic wall inserts with it],,mount it and run some of that 2 wire cable that you got at your building supply,should be 2--2.5 at least.

mount a 15 amp breaker outside your shower right by the door,run your wires from that to your shower heater,and be sure to connect a wire inside where instructed for the ground and run it either to a steel pipe or outside to a ground rod driven in the ground, Get some of the hose that has the fittings on the ends like you used under the sink and hook to a valve at your water supply,you will want a valve to shut it off so you can clean the little filter in the water inlet to the heater,then run your 2--2.5 wire from someplace to the breaker and enjoy.

if your supply is very far and you do not have the water supply in the shower now,then run some 1/2 or 3/4 plastic pipe in close to the heater.And if you got 3 wire service then hook the green wire to the grounding lug inside the heater.and you will pobly have to route it around the breaker as I never found any with a place for the 3rd wire.

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You are correct,and due to the fact that they are mostly plastic , they are in fact "double insulated" and a ground wire from the internal lug to earth is all that is needed unless you have 3 wire grounded system in use in your house.

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1. The GFI will function without a ground connection. It measures the current flow on the hot and netural side. If there is a difference, it trips. Of course it's better to had a ground connected to the unit.

2. It is possible to have the entire house running via a GFI.

These are sold at Home Pro or other building supply places.

Good luck.

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Have five of these units of the shower type. The ELB is indeed a GFI device and all the Japanese brands come with it as part of the unit. But it should still be grounded and there will be a terminal for this. Even if only a wire out the window to your aircon ground do it. Some units (at least in the past) could be prevented from trip by the mechanical test button so don't place your life on the ELB working. I would also advise looking inside and making sure that there is a a plastic or ceramic connection between the shower hose and the metal pipe out of the heater tank. Also advise not changing shower house to metallic type, even if it looks better.

Have found the 3500 watt units to be fine here in Bangkok. Up in Loei might want a hotter unit. There is a thermostat for changing the temp. Some have a push type on/off for water flow (which can fail) or you use control valve into the unit for amount/on-off control. You don't need any bypass.

Less common type is the tank units, usually from Europe, that are designed for multi point operation. These usually hold a tankful of hot water and heat more on demand. I had a hotel room in Chiang Mai using these and would never buy after that experience. But admit they probably had not been installed correctly.

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If you install your own ground/earth and it is not referenced, connected to the power company grid ground, your ground can end up becoming 'live', referencing the entire neighborhood. Connection to the power company grid is a direct mechanical cable connectiion to the transformer from which your power is sourced.

A friend and I once dealt with a trailer park where the ground, soil itself, itself floated at about 100 volts. Over 50 ground rods at individual trailers were useless as the entire area was 'hot'.

If you install your own ground in a non power company referenced area, you should use a minimum of 3 5/8 inch thick copper rods, each 8 feet or longer. The rods must go into the water table at the seasonal lowest point. This may not be adequate. One dry hilltop location had to bury 200 feet of galvanized pipe 10 feet down. The transmitter for the local Coast Guard on top of a high bluff had to have 1200 feet of copper grounding rod. One inventive person placed rod alongside two 30 meter long leach lines for his septic system which seemed to be effective.

If you use an ohm-meter to check ground, the target resistance is 1/2 ohm maximum. This reduces the current availability to a theoretical /below lethal/.

Acceptable current leakage for appliances under normal circumstanced is 20 milli-amps. For compromised persons, as in wheel chairs, 50 micro-amps.

GFI or GFCI. Ground fault circuit interrupters. These sense when there is current flowing in a ground wire and open the hot leg or legs. Some GFI units also incorporate ELB circuit control.

Disadvantage: there must be a solid reliable ground to the GFI unit as described above.

ELB. Earth leakage breaker. These match the current between two hot legs or hot and neutral. If current goes elsewhere, through a ground wire (or through you), they disconnect the current.

Disadvantage: The current sense accuracy can be as much as +/- 20% depending on quality of manufacture.

For the ELB to be effective, you MUST ground the appliance. Otherwise the leaked current it checks may be the current going through you. Most of these devices are rated by the manufacturer to trip at 15 milli-amps (to stay under the 20 milli-amp rule of thumb, above). A ground specifically for the protected appliance, isolated from all other current sources, is acceptable.

If you do not have a power company grid connected ground or fully effective ground you have installed, multiple ELB units in a household electrical system can be defeated if the ground potential above zero volts. That is, the ground itself contributes some of the current leakage which the ELB ignores.

When in doubt, find an electrical engineer with a clue. There is no truer statement than, 'In application, Murphy's law supersedes Ohm's.'     

Bite the bullet, shower in ambient temperature water don't be so soft.

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ELB. Earth leakage breaker. These match the current between two hot legs or hot and neutral. If current goes elsewhere, through a ground wire (or through you), they disconnect the current.

Disadvantage: The current sense accuracy can be as much as +/- 20% depending on quality of manufacture.

For the ELB to be effective, you MUST ground the appliance. Otherwise the leaked current it checks may be the current going through you

Read para one and then two. You can't have it both ways. In fact called GFI/GFCI/ELB/ELCB they do preform without a ground (and that is why the name GFI/GFCI is so controversial) as they compare what is on the hot side and what is returned on the neutral. If the current is finding another path to ground (like through you) it shuts it down. If you ground the unit it should trip before you touch it so that is an added protection. They are great and am a strong supporter of using them (installed on my present home here in Thailand in about 1977).

As plugs are not polarized here any ground is better than none. Even if floating it will still work to activate protection.

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1. The GFI will function without a ground connection. It measures the current flow on the hot and netural side. If there is a difference, it trips. Of course it's better to had a ground connected to the unit.

2. It is possible to have the entire house running via a GFI.

These are sold at Home Pro or other building supply places.

Good luck.

bangsaen bob,

You sound pretty knowledgable about this.

I have tested GFI recepticles here in the states that did not have the green ground wire on them. The tester showed and open ground fault code.

From what your saying though the recepticle still fuinctions.

I live in an area of San Diego where all the houses, built in 1964, are two wired with no ground wire. Exccept at the sinks and washing machine recepticles, where the third wire is clamped to a copper plumbing pipe.

All the rest have the white/neutral wire tied to the earth ground in the circuit panel.

Is this how two wire systems are run in Thailand?

I have asked many electritions about this and they say its a ground but not a true ground?

No one I know has ever been shocked either. Except by the bill :o

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I never use hot water, my gf does. I'm thinking of installing a simple plastic bypass since I've tried connecting the showerhead directly to the water tap, much more pressure that way even if the unit's pressure adjustment was set to FULL.

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That is because of the smaller diameter of the tubing thru the heater unit and possibly because if is hooked up with a flex hose ,the inner dia. of the hole in it is smaller than regular pipe. And also the fine screen strainer in the heater unit intake might be partially plugged.

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I live in an area of San Diego where all the houses, built in 1964, are two wired with no ground wire. Exccept at the sinks and washing machine recepticles, where the third wire is clamped to a copper plumbing pipe.

Having been around that long can say the your outlet box itself should be at ground if everything is still connected. Rather than use wire the steel conduit connecting everything should be the ground path (again assuming they used it). When people wanted a ground in those days they tied a pigtail to the screw on the cover plate. This depended on a number for screw type connections remaining tight and free of corrosion so is not too reliable. Another methods was to tie each outlet box together with a green ground wire and that was better but most people continued to just use the old non ground outlet strips.

Here in Thailand there is seldom steel conduit used, plastic for everything. Most wires are surface mounted on the cement walls and until recently two wire. Few homes have neutral grounded in power panel (if they even have a power panel) but there normally is a ground at the power pole feeding the home. Copper is not used for plumbing here.

As for the GFI receptacles believe what Bob said is the GFI still functions - the receptacle will turn off in the event of leakage. You can check that by plugging something into it and tripping the test and see that power is stopped.

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When I built my house I opted for 3 phase elctrical, even though I don't understand it, as it was supposed to be better.

As a result I was pointed to a Seimens automatic electric water heater and have two installed. They work fine, PROVIDING, you have enough pressure. I didn't, so stainless steel tank and water pump bought and installed.

Then the water was too hot. Evidently, a temperature controlled water valve is required so the hot and cold water is mixed by the valve, otherwise too hot or no hot.

Out came the repairmen again and they were able to reduce the amount of the voltage to the untis so they work at half capacity and I can use the water at full hot and it is comfortable.

What I have learned, and wished I did differently, was to buy one of the many Japanese units available at different prices at a lot less than the 9k I paid, that have a temperature control knob on the face of the unit and place the unit in the shower so you can adjust the temperature. Relying on a mixer valve to mix the hot with the cold to reach a compatable temperature is just too complcated and I am not sure to this day whether it would work properly.

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When I built my house I opted for 3 phase elctrical, even though I don't understand it, as it was supposed to be better.

As a result I was pointed to a Seimens automatic electric water heater and have two installed.  They work fine, PROVIDING,  you have enough pressure.  I didn't, so stainless steel tank and water pump bought and installed.

Then the water was too hot.  Evidently, a temperature controlled water valve is required so the hot and cold water is mixed by the valve, otherwise too hot or no hot.

Out came the repairmen again and they were able to reduce the amount of the voltage to the untis so they work at half capacity and I can use the water at full hot and it is comfortable.

What I have learned, and wished I did differently, was to buy one of the many Japanese units available at different prices at a lot less than the 9k I paid, that have a temperature control knob on the face of the unit and place the unit in the shower so you can adjust the temperature.  Relying on a mixer valve to mix the hot with the cold to reach a compatable temperature is just too complcated and I am not sure to this day whether it would work properly.

I have the same problem now that you had. I have a Stiebel Eltron (German) heater in the bathroom. Only when the water pressure is high enough (e.g. after it has rained) or the water temperature in the well is cold enough, can I get WARM water. The heater has two settings and both are too hot. I have to turn the cold/hot mixer tap to "hot" to get the heater to come on, and then when the water is hot enough I have to turn the mixer towards "cold" to get warm water. But then the heater goes off because the pressure is too low! So after all the warm water has gone (30 seconds) I have to move the mixer again to "hot" and repeat the process.

I would very much like peope with good heaters (that is, ones with variable temperature control on the heater and ones which work with medium to low water pressure) to post the make and model of their heater. I think a lot of people have this problem and would love to know which one to buy. Thanks

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RDN: You described my problem much better than I did!!

If you have your installation or operating instruction book you might check to see if they have variable wiring options. Within the unit, there may be various contact points, that when varied, give you various voltage options. I was able to lower my water temperature that way, and it is a lot better, since I use it full hot and the water is comfortably warm. Far from ideal, however.

My shower control valve is a Coto, and certainly not a temperature control model.

In western countries, there are shower control vlaves that have a temperature control feature that adjusts the temperature of the water it emits automatically as the temperature varies from the supply side. A mandatory feature when you are in large buildings where water is supplied from central water heaters and demand varies the temperature markedly. They are more expensive than a normal mixing unit.

I haven't looked locally for such a valve because to tear out the tiled shower wall to install new valves is too daunting for me. Believe me, I am so close to just buying a National luxury unit for around 5K and installing it to solve my problem. Especially when you can just connect it to the outlet pipe and connect your shower head to the heater.

I have a fixed shower head coming out of the wall, my preference, but many prefer the hand held type. Perhaps the National requires a hand held, I don't know.

Good luck and let us know developments. Thanks

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Pro and RDN,

I have a Siemens 'on demand' water heater mounted in the bathroom that provides hot water to: shower/tub; bathroom sink; kitchen sink; and wet bar sink. To put individual heaters at each location wasn't a realistic option. All locations have mixer plumbing (a chrome arm you maneuver left or right) to obtain correct temperature delivery. And except for the shower/tub, all works fine.

Reading RDN's post, I have to chuckle because I have the same problem with my shower -- goose it to the hot position to get the coils to heat, then back-off to something tolerable, only to have water pressure on the hot input fall too low, and thus stop heating. My workaround is to run the water at the sink, which bleeds off some of the heat at the shower, but since water pressure is maintained with the added demand at the sink, I now get the correct mix in the shower.

As far as I know, I don't have a variable switch option in the Siemens that could lower juice going to the coils (at least there's none on the outside of the box). Like Pro, I could reconnect the wires inside; but then the non shower/tub locations would not be optimum, as they are now. Oh well, guess I'll keep heading for the sink before the shower.

Oh, Pro, you're not the only one who doesn't understand three-phase electricity. I got talked into it, although some said it wasn't necessary. I believe I heard it was more stable (less brownouts), but you could have fooled me (thank goodness for UPS). Anyone care to explain the difference between two and three phase electricity? What kind does the Western world have?

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I would very much like people with good heaters (that is, ones with variable temperature control on the heater and ones which work with medium to low water pressure) to post the make and model of their heater. I think a lot of people have this problem and would love to know which one to buy. Thanks

I've got Sharp WH-505 units installed in each of the bathrooms, with a variable temperature on the front etc. All feeding the hot side of mixer taps / shower / etc.

Have had them a couple of years, and never had a problem with any of them.

However we do have a big metal tank and water pump outside, so I don't know how it would cope with low water pressure...

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JimGant: Misery loves company, so the saying goes. Thanks for your post.

Your quite right about the sacrafice. My kitchen sink is fed by the Siemens in Bathroom #1 and since I changed the wiring for shower comfort terperature, the kitchen sink temperature is just warm, not hot, as one likes for kitchen work.

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Anyone care to explain the difference between two and three phase electricity?

Normal home electric supply here is single phase 230v 50Hz power. House meter will have a rating of 5 or 15 amps (they allow much higher power so 15 amps will supply most homes). Those with higher requirements opt for three phase, 45 amp meter supply.

The power transformers you see on poles output three phase. During most local power failures only one of these will have fuse blow so if you have three phase power in you home you may have both alive and dead outlets. If you check the neighborhood you will see some homes still have power and other do not as they try to equal use on each phase so one home will be on phase one and the next phase two etc.

There is no advantage here with having three phase to home and none of the home equipment needs it (industrial motors may). As your outlets will be on phase one/two or three brown outs will occur as with anyone else on those phases.

With the low voltage of the USA/Japan multi phase power is required to obtain 230V for cloths dryers and such but here it is just needed if your home has huge requirements with few other users to equalize the transformer use with. An upcountry home where you have ac and most others have fans might be a good use of 3 phase power (if they wire your home to equalize usage).

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Anyone care to explain the difference between two and three phase electricity?
My ex-colleagues in the UK (still working :D ) always told me to be very careful handling 3 phase because the voltage between any two phases can get up to 440 volts -"very lethal" - compared to a single phase and ground which is only 220 volts -"slightly lethal". :o
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Lop,

Many thanks for the explanation. We actually did have a transformer blow one day, and yes, some circuits worked in the house while others didn't. I was completely mystified.

Just to be sure I understand-----

An upcountry home where you have ac and most others have fans might be a good use of 3 phase power (if they wire your home to equalize usage).

When you say 'wire your home to equalize usage,' you're saying all three phases are coming into my circuit breaker box, but then each is distributed differently around the house (thus explaining why some worked and others didn't when the transformer blew)?

And I am upcountry, most of the locals have fans, and I (because the wife's postmenopausal :o ) have too many ACs. So, you're saying, getting three phase juice might have been justified? I hope so, as I'm sure I paid more than had I only gotten single phase.

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Pro,

Perhaps the National requires a hand held, I don't know.

Hand helds are easy to get used to, as long as you've screwed in a decent shower head -- and you have a second 'farang' bracket on the wall. Thai-heighth brackets are always too low, even, I think, for most of them -- the water hits you right smack in the chest. Not good. Very easy to mount two brackets, however.

A related observation:

CarreFour's lav in ChiangMai has mounted its urinals too high for many Thais (there is, however, one kiddy urinal that's very popular). I chuckle every time I go in there, as the Thais need to be taller than average, or very well hung, in order to negotiate the urinal's threshhold.

I guess 'American Standard' plumbing comes complete with American standard mounting instructions. :o

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JimGant:

Speaking of mounting istructions: My American Standard toilets, made in Thailand by Thai subsidiary, did come with mounting instructions, however, Thai plumber engaged by my developer had one hard mounted before I caught him not using the wax O Ring.

It was explained to me that Thais prefer a hard mount, that is just placing the toilet over the drain pipe and setting it in a bed of some form of plaster that creates a hard bond. The danger I could see was that the toilet had no flexibility so after a number of hard "jars" from big ass farangs, cracks would occur through which discharge water would seep.

So far, 2 years, no problem with this "hard" mount. The other toilet was installed, upon my insistence, with the wax O ring, per instructions.

The cheap plastic toilet tank mechanism has failed in one of the toilets, regulator leaks, so replaced this week with the U.S. "fluidmaster" replacement kit from homepro. Expensive, but effective.

You might explore availability of temperature regulated shower fixtures. I will. The more I think about it, my shower heads were located on outside walls, by my design, to effect valve replacement, so I could replace my existing valves with temperature regulator types without disturbing my inside tile.

Will advise when my lazyness is dispelled and the desire for a "new project" dvelops.

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When you say 'wire your home to equalize usage,' you're saying all three phases are coming into my circuit breaker box, but then each is distributed differently around the house (thus explaining why some worked and others didn't when the transformer blew)?

Right. If you have several a/c that normally run at the same time they should be on different phases in your home.

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So far, 2 years, no problem with this "hard" mount. The other toilet was installed, upon my insistence, with the wax O ring, per instructions

Yeah, but where in Thailand will you get a replacement when it finally leaks? I know these wax seals are right next to the Fluidmasters at Home Depot (States), but I don't recall seeing any at Home Pro.

I imagine they use hard mounts because every floor over here is concrete. This wouldn't seem too practical, however, on wooden subfloors, like in the States.

Just curious -- did you have to affix a matching flange on the pipe to accomodate the seal and boltdown? I haven't had any problems with the hard mounts; but if I do, might switch to wax, assuming all the parts can be obtained in Thailand(?).

(If we keep this up, we're going to hear from the plumbers' union :o )

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(If we keep this up, we're going to hear from the plumbers' union  )

I wish there was one. If I decide to improve my hot water supply and find a temperature contolled valve, a daunting task is how to find a modern plumber in CMX.

The one the developer chose, failed to connect one of the toilets to the septic tank.

He paid highly for the oversigt when he had to do the job after a month of use and the long run to the tank finally reached its maximum capacity.

None of the usual bolt down metal fittings were present with the American Standard Toilet except the actual bolts that were driven into the concrete to which the base was then bolted to. The wax O ring was merely laid ontop of the concrete floor and discharge pipe. OK so far.

P.S. The hard mount toilet was mounted too close to the tile wall so the tank lid doesn't fit all the way on the tank. I suspect when the rough layout of the plumbing was done, the thickness of the wall and tile wasn't known and there is no standard to follow, so the drain pipe was set without allowing enough margin for error.

If a moderator is reading this, he might suggest to George that we start a new section in the forum for "Home Improvement" or the like.

A thread in the proposed "Home Improvement" topic could be entitled "Beware of: when you are building" I certainly could be a major contributor as I doubt any farang has encountered more "goofs" during construction than I, and that was with two visits to site every day!!

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