Multi-Point Water Heaters

[T_Dog]

Anyone have any experience with the 6KW Carte water heaters? Looking to buy one and appreciate any advice out there.

[thatguy]

Are you running a shower and a few sinks? 6kw seems a little light. I ended up with the highest watt shower only unit before we got reliable winter showers. I think it was 8kw. This was in Issan, never checked the incoming water temps over the year.

[T_Dog]

We had a 12 KW Siemens unit in a rental house and had to disconnect half the elements as it was just too hot. Turning down the mixing valve at the shower to make the water a comfortable temperature would cause the heater to switch off, so it was either too hot or freezing. At 6 KW it was about perfect. Would buy another Siemens unit if I could find one, but they don't seem to be on sale in Thailand any more.

[lopburi3]

If not available suspect for that reason as found them useless in hotels I stayed that used them as scolding hot or none as just could not control as normal cold here is almost hot. In years past had gas heater that had to block 75% of burners (but that was single tap so all water was heated). Our ice field solutions often do not work well here. But electric heaters should be able to compensate if designed properly. Obviously these were not designed for Thailand (below Loei province).

[T_Dog]

If not available suspect for that reason as found them useless in hotels I stayed that used them as scolding hot or none as just could not control as normal cold here is almost hot. In years past had gas heater that had to block 75% of burners (but that was single tap so all water was heated). Our ice field solutions often do not work well here. But electric heaters should be able to compensate if designed properly. Obviously these were not designed for Thailand (below Loei province).

That would be the Siemens unit! I found though that they are very easy to configure for less power. Inside there was a terminal strip that you moved jumpers on to get it to the correct power setting for your application. I doubt any electrician that installed them ever went through that step though. Construction quality was excellent.

[sotsira]

If not Siemans, then go for a 6kw AEG they are similar in quality and service, and readily available

at most retailers.

[T_Dog]

If not Siemans, then go for a 6kw AEG they are similar in quality and service, and readily available

at most retailers.

Had a friend that bought the AEG and they complain about not having enough capacity for a shower. Did you have one?

[sotsira]

If not Siemans, then go for a 6kw AEG they are similar in quality and service, and readily available

at most retailers.

Had a friend that bought the AEG and they complain about not having enough capacity for a shower. Did you have one?

Are you sure your friend's one was a multi point?

Also everyone's water pressure is different, i use the AEG multi point 6KW in my condo and in 3 other condo's

all work very well but the water pressure is high and that is important for any water heater to work efficiently.

They cost 5000bt. and had them for over 4 years now.

[T_Dog]

If not Siemans, then go for a 6kw AEG they are similar in quality and service, and readily available

at most retailers.

Had a friend that bought the AEG and they complain about not having enough capacity for a shower. Did you have one?

Are you sure your friend's one was a multi point?

Also everyone's water pressure is different, i use the AEG multi point 6KW in my condo and in 3 other condo's

all work very well but the water pressure is high and that is important for any water heater to work efficiently.

They cost 5000bt. and had them for over 4 years now.

Yes, I've seen it and it is a nice looking and very compact unit. Could very well be a pressure related problem he has. Guess I have to put the AEG back on the list. Thanks for your inputs.

[T_Dog]

Still shopping for a water heater. Mex (Thai manufactured/Italian designed) makes a 9000 watt heater that looks pretty nice. Anyone buy one yet? They are actually available unlike most other brands that are not so it is on the current radar.

[PattayaParent]

I can recommend Stiebel Eltron.

I've a couple of 4500W units in my flat in Pattaya and the water is too hot.

[T_Dog]

I can recommend Stiebel Eltron.

I've a couple of 4500W units in my flat in Pattaya and the water is too hot.

Ended up buying a Stiebel Eletron 9000 watt single point heater and could not be happier with the choice. It is very configurable and we tuned it down to 6000 watts and even then, a front panel switch allows further adjustment. The flow sensor works really well as we can turn the shower mixer valve down to nothing without worrying about a burst of cold water. Two showers pulling water at the same time are no problem.

[regedit]

Other than size, what's the difference between the multi-point electric water heaters (that look like a shower unit) and the 'mini' multi-point electric water heaters (they're about half the size), assuming both are 6kW ? Are the mini's more for sinks than showers+sink ? Lower temperature ? Thanks.

[lopburi3]

Not sure what you are talking about but perhaps the units designed for full hot usage with hot/cold mixing taps? The wall shower units are designed for adjustable temp control of output water that is not mixed with cold.

[regedit]

To clarify, see attached pictures. I think you're right - the mini seems to be for use with mixer taps. I have the plumbing in place for mixer taps to the shower and sink. Just wondering if one eWater Heater type is better than the other in terms of performance. Thanks.

[lopburi3]

Expect the unit designed for full temp will be better if using mixer taps as shower units are not designed to heat the water hot enough to actually mix with cold. This will also provide you better water flow having the two sources. The only issue I have with such units is they often do not work well with low water pressures found in Thailand. Recall several hotels in Chiang Mai using them that could never get anything but scalding or cold from taps.

[TongueThaied]

I bought a 10 KW Panasonic, model no. DH-10BM1T Multipoint, 7,900 baht, that has a front switch that allows it to be switched from 6KW to 8 KW to 10 KW. Takes a hell of a cable, though, that 10 KW, 13 mm and a 50 amp breaker.

[electau]

The problem with instantaneous hot water systems is the electrical demand in amps/ kW on the electrical supply and on the supply network.

If there is no other alternative to instantaneous systems one should limit each one to less than 20A and a single phase connection.

Storage systems solar thermal or storage systems with a heat pump are the best way to go if practicable.

You also require a reasonable water pressure at the point of use. eg 30psi.min.

[JAS21]

Expect the unit designed for full temp will be better if using mixer taps as shower units are not designed to heat the water hot enough to actually mix with cold. This will also provide you better water flow having the two sources. The only issue I have with such units is they often do not work well with low water pressures found in Thailand. Recall several hotels in Chiang Mai using them that could never get anything but scalding or cold from taps.

The difference between multipoint heaters and shower heaters are that multipoint are flow switch energised whereas single shower heaters are pressure operated.

If you install a flow energised heater for the shower you are very likely to get a problem if you reduce the flow ... ie water too hot so you add more cold and the flow through the heater reduces ... and the flow switch will cut off the electric supply.

That is why you need to be careful when selecting a multipoint as using it just for one shower can cause problems on low flow. We had a multipoint Panasonic and it was renown for tripping out on high temp ... binned it and bought a Turbcra. Great temperature control and haven't had any problem in two years.

[JAS21]

Sorry Guys ... the make is Turbora ... I think from Homepro. The company manuf or importer is in Pathumtani. You can google for the info ... pic attached. I fitted it a couple of years ago ... always ment to tidy the spaghetti.

Edited August 14, 2012 by JAS21

[dave111223]

I need some advise about water heaters in my house that's currently under construction.

At my condo I have a multi-point 6000W Fujika heater which works awesome, very hot if you put it full heat without mixing any cold you'd literally burn yourself badly.

The heater is installed on the wall outside on the balcony, which was a good idea as the connections have zero corrosion after 6 years (which I'm assuming that would have if box was inside the steamy bathroom all the time)

At my house I have 4 bathrooms, and was planning to use 2 multi-point heaters, with each heater powering 2 bathrooms (as the bathrooms are group one above the other). I plan to only be using 1-2 points at a time, but maybe 3 points MAX. I also plan to install the heater on the outside wall.

So I figured a couple of 10000-12000W units should work good.

But I went into Boonthavorn and the sellers now have me confused. They say that multi-points are no good for this situation (I figured if 6000W is boiling hot for 1 shower, 10000W should be pretty hot for 2 or 3 showers? no?) Also we have a 3 phase power hook up to gives us the option of using a 3 phase heater....but when I asked about the 3 phase unit they were making sucking-lemon faces and kept saying that one was "for a factory"...hmmm ok? They kept saying that I should get a water heat tank instead.

However I'm concerned that the water tank is going to use more electricity as it is keeping the water hot all the time, or is this an incorrect assumption? Also if the tank runs dry then you're going to have to wait awhile to get more hot water right? (Not to mention that it will look big and ugly mounted on the wall)

What would you suggest, here are a few options I am considering:

• 12000W STIEBEL ELTRON: 12K THB
  
• SIEMENS 3 Phase heater: 12K THB
  
• 80Liter Tank heater STIEBEL ELTRON: 11K THB
  

[dave111223]

Note I may have mixed which of the instant heaters requires the 3 phase.

[JAS21]

Why don't you just put one 6kW heater in each bathroom ... then they can be individually adjusted for user preference. Going to cost about the same as what you are planning.

I certainly wouldn't go for a shared multipoint heater. Just think ... three people showering ... then two of them stop ... the third person may come running out of the shower looking like a lobster.

[Crossy]

I'm with JAS, I would avoid, but if you are going to run several showers off a multipoint they should all be at about the same level and you really ought to use thermostatic mixer taps (expensive) to avoid potential lobsters.

[T_Dog]

I can recommend Stiebel Eltron.

I've a couple of 4500W units in my flat in Pattaya and the water is too hot.

Ended up buying a Stiebel Eletron 9000 watt single point heater and could not be happier with the choice. It is very configurable and we tuned it down to 6000 watts and even then, a front panel switch allows further adjustment. The flow sensor works really well as we can turn the shower mixer valve down to nothing without worrying about a burst of cold water. Two showers pulling water at the same time are no problem.

Just noticed I used the wrong terminology here as the unit is a multi-point heater. No problems at all using showers with simple mechanical (non-thermostat) shower mixers on two floors. It handles two people showering simultaneously with no problem and no noticeable flow changes with 25 mm PP-R pipe connecting everything from the utility room onward. As JAS points out, multi-point heaters use flow sensors to turn on, not pressure so they do have to be used with mixing valves.

[cmsally]

Just wanted to resurrect this thread. Have been looking at multipoint heaters. From what's available seems to be choice of Mex, Stiebel and Panasonic. Panasonic they only seem to have the 6kW (no 6kW/8kW in stock). The Stiebel is adjustable and the Mex apparently also adjustable.

Any more experiences? Will post models later and also going to look at the AEG mentioned at beginning of thread.

[oxymoron]

Off topic but why use electric (multi-point) if in/near Chiangmai. EGAT at Maeon on highway 1376 have a good range of Solar Storage Tank HWS. All stainless steel and IMHO reasonably priced.

[Negita43]

Here is a question about the use of multipoint heaters: If they are flow controlled do they work with cold water tanks and pumps which themselves are flow controlled?

[Crossy]

Here is a question about the use of multipoint heaters: If they are flow controlled do they work with cold water tanks and pumps which themselves are flow controlled?

There should be no issue working with any automatic water pump, provided the flow is sufficient to operate the switch.

[lopburi3]

It is just a water flow valve that turns the electric on/off so heater unit is on all the time but only heats when there is enough water flow to move that valve (to prevent overheating unit). Most dedicated shower units have been using this system for several decades now as a safety feature and many are rated for multi point operation. I have not turned off a shower in at least 20 years.