Water Heaters For Showers

[Raindancer]

Does anyone know where I can purchase a water heater of 8 KW or above in Chiang Mai to provide sufficient heated water to a power shower.

Many Thanks

[Mrjlh]

Just make sure your wiring can handle the extra electrical load. Couple of years back same discussion on TV. Think you need 6.5mm wire minimum plus circuit breaker needs updating. Double wire might work but not sure. Normal wiring found in buildings is 4.5mm. Best to consult electrician. Home-Pro should carry it.

[Raindancer]

Just make sure your wiring can handle the extra electrical load. Couple of years back same discussion on TV. Think you need 6.5mm wire minimum plus circuit breaker needs updating. Double wire might work but not sure. Normal wiring found in buildings is 4.5mm. Best to consult electrician. Home-Pro should carry it.

I think the wiring is ok...Last night after one shower that my wife took...it just packed in... the current heater is 6 kw. But is probably 6 years old. The fuse is Ok and functioning and the electric current to the heater is working but it is not responding. And we have had also some problems during the winter of the water heating up.

Any thoughts or experience would be appreciated

[lopburi3]

Normal wiring found in buildings is 4.5mm

Believe you are thinking about the US rather than Thailand. Normal wire in Thailand is 2-2.5mm (or less many places). The voltage here is 230 so the US wire size (120v) is not required.

[Mrjlh]

Normal wiring found in buildings is 4.5mm

Believe you are thinking about the US rather than Thailand. Normal wire in Thailand is 2-2.5mm (or less many places). The voltage here is 230 so the US wire size (120v) is not required.

You may be right. I just remember there was a very good thread about it covering the exact same thing. One of our members is an electrician and did some calculations based KW loads involved. It's the load that the wire can carry that is of concern not the voltage.

[Raindancer]

Normal wiring found in buildings is 4.5mm

Believe you are thinking about the US rather than Thailand. Normal wire in Thailand is 2-2.5mm (or less many places). The voltage here is 230 so the US wire size (120v) is not required.

Thanks...How can I ensure that the wiring is correct. But this does not deviate from my original statement of the problems the water heaterI have mentioned. Any views on that?

[lopburi3]

Believe you have Global House and Home Pro and likely other suppliers to contractors up there.

A good calculator for wire size seems to be here - as can be seen even a small 1.5mm wire should work - but I would use 2.5mm if have to re-wire (which you probably will not have to do).

http://circuitcalculator.com/wordpress/2007/09/20/wire-parameter-calculator/

Yes it is the VA which is of concern and that is Voltage times Amps so when the voltage is double as here half the amperage is all that the wire needs to supply (about half the wire size).

Edited April 12, 2011 by lopburi3
Info for 8A rather than 8KW

[Raindancer]

Believe you have Global House and Home Pro and likely other suppliers to contractors up there.

A good calculator for wire size seems to be here - as can be seen even a small 1.5mm wire should work - but I would use 2.5mm if have to re-wire (which you probably will not have to do).

http://circuitcalcul...ter-calculator/

Yes it is the VA which is of concern and that is Voltage times Amps so when the voltage is double as here half the amperage is all that the wire needs to supply (about half the wire size).

Thanks for the info..Will check it out with various suppliers.

[bikerjoy]

get yourself a GAS waterheater...safe, powerful hot water, no electr. shocks and always hot even when they have power cuts...

for around 5000 b. at homepro.

cheers,

[lopburi3]

Actually those gas heaters were all that was available 30 years ago and they were not safe - many people died as they closed bath windows during the coldest day so no venting took place. The electric heaters solved that issue (although they have there own). Suspect many places now prohibit gas containers in residential buildings.

I can say in Bangkok the gas heaters were total overkill and most of the ports had to be blocked to keep temp below boiling on most days of the year. Upcountry during coldest period suspect they would work well but once sun starts to heat water storage tanks they are overkill.

[powderpuff]

So you think that 1.5 mm2 or 2.5 mm2 wire is ok for an 8,000 watt water heater?

I don't. It's pulling about 35 amps.

[lopburi3]

OOps. Read it as 8 amps instead of 8kw.

In that case 4.0mm would seem appropriate.

[Mrjlh]

Here's the answer to your problem:

http://wiki.answers....rom_main_supply

awg 6

inch 0.162

mm 4.1

mm2 113.3

Edited April 12, 2011 by Mrjlh

[BB1955]

I bought mine at home pro and had them install it . Not sure what size it is but it will run you out on full . I think they charged me 500 baht to put it in and the heater was about 3 thousand baht ......

[wolf5370]

8Kw for a shower - sheesh you must like it real hot - just had a 5.5 Kw heater put in (fully fitted - BigC did the fitting for 800Baht plus 80Baht for extra wiring - back to consumer unit and with fused circuit breaker and earth fitted) - shower with ECB was just b1,250 - bargain. Not had it above 1/3rd power (temp) as that is plenty hot enough for me.

[Raindancer]

8Kw for a shower - sheesh you must like it real hot - just had a 5.5 Kw heater put in (fully fitted - BigC did the fitting for 800Baht plus 80Baht for extra wiring - back to consumer unit and with fused circuit breaker and earth fitted) - shower with ECB was just b1,250 - bargain. Not had it above 1/3rd power (temp) as that is plenty hot enough for me.

I was just being extra safe. But the current heater is fine in the summer, but in the winter it barely gets warm. Bear in mind that my water system is pumped to the shower by an electric pump from the storage tank from the garden to the upstairs shower rooms. When I lived in Bungalow without the same water supply system, they had a 4.5KW heater installed and never had this problem.

But thanks for the info about Big C and its prices.

[Raindancer]

Thank you to everyone who took the time to provide all the excellent information. And also thank you to the member who PM'd me with what might be a simple test and solution for the existing heater.

I will now check out all the options open to me.

[jackr]

Don't scrimp on cable size with showers. You should have 10mm2 cable in there for 9kw (up to 41 amps @ 220v); 6kw would be 6mm2 min. How the cable is run (conduit, on the wall, in the wall) as well as cable length also have bearing on current drawn. Have 6kw showers with booster pump in CM and find them plenty enough.

[Raindancer]

Don't scrimp on cable size with showers. You should have 10mm2 cable in there for 9kw (up to 41 amps @ 220v); 6kw would be 6mm2 min. How the cable is run (conduit, on the wall, in the wall) as well as cable length also have bearing on current drawn. Have 6kw showers with booster pump in CM and find them plenty enough.

Many thanks.

[noise]

get yourself a GAS waterheater...safe, powerful hot water, no electr. shocks and always hot even when they have power cuts...

for around 5000 b. at homepro. cheers,

When I first came to Thailand, that was all I saw, the gas ones. I agree, they are great (other than needing a place to put the gas tank as they had pilot lights).

All your other replies were focused on different aspect of the wiring. Here is another thought. I have 2 types in my house. One that has the potential to have to fill a bath tub with hot water is a high wattage one wired with 3 phase wiring. If you do not have the 3 phased wiring to the bathroom, it may limit your options.

Another thought applies to both your old one that you think died and buying a new one. This heater I have has a pressure switch/governor on the power. If the water pressure (equating to water flow) is not great enough, the switch opens. The theory being the heater will burn out if there is not enough water flow to conduct the heat away.

So, does your old one have that (not all of them do)? And if you buy a new one, you need to ask about that and make sure you match it to your house pressure or reset your pump output to match the heater.

[Raindancer]

So, does your old one have that (not all of them do)? And if you buy a new one, you need to ask about that and make sure you match it to your house pressure or reset your pump output to match the heater.

Not sure. I will have a look at it with the electrician and ask the question. If the old has died, I will certainly ask the question regarding any new one that I purchase.

Thank you.

[simoncnx]

my advice:

Dont use electrical one - too much current and most over 6kw are 3-phase. I suggest you use a gas powered 1

[harrry]

I have just installed a 6kw panasonic and I am pleased with it. Plenty of hot water for a really good shower though I must agree not good eough for a bath.

Install with 6mm. Your hose and families lives are worth more than the saving from 4.5mm. Also ensure it is fully and correctl earthed and the earth line has the capacity to handle full failure current.

[Raindancer]

I have just installed a 6kw panasonic and I am pleased with it. Plenty of hot water for a really good shower though I must agree not good eough for a bath.

Install with 6mm. Your hose and families lives are worth more than the saving from 4.5mm. Also ensure it is fully and correctl earthed and the earth line has the capacity to handle full failure current.

Thanks. Harry. The cable is 6mm and I also have Safe T Cut for the whole house. Just going to have a few further checks carried out on the variable power/heater flow switch to ensure that it is also not faulty.

Thanks everyone.

[Dellboy218]

I am a little surprised at people getting 3 phase for a 6kw shower. Showers in the UK are generally avaailable up to 10.5kW on single phase and one maker recommends for showers up to 8.5kW a cable of 6mm if it is surface mounted or mounted in a conduit and 10mm if it is fitted inside an insulated wall. Your average 25000BTU air con runs close to 8kW and they are single phase. ( Doubtless someone will pipe up and tell me they have a 9000BTU running on 3 phase.)

[Naam]

Your average 25000BTU air con runs close to 8kW

that would be a real energy guzzler! make that max 2.5kW for an old rattler

[Raindancer]

Your average 25000BTU air con runs close to 8kW

that would be a real energy guzzler! make that max 2.5kW for an old rattler

To everyone who has replied. Many thanks for all your helpful ideas/suggestions. I wish to close this topic as I have everything I need now and the matter is resolved.

Of course you may wish to go on debating many answers on this subject with each other and I wish you all well and happy discussions.

Good to know that there are so many helpful people out there.

[Dellboy218]

Your average 25000BTU air con runs close to 8kW

that would be a real energy guzzler! make that max 2.5kW for an old rattler

1 British Thermal Unit (Btu) = 0.0002928 kW

[Crossy]

Your average 25000BTU air con runs close to 8kW

that would be a real energy guzzler! make that max 2.5kW for an old rattler

1 British Thermal Unit (Btu) = 0.0002928 kW

Indeed, but a modern A/C will pump about 3 times it's input power, so a 25,000 BTU unit will draw about 2500 Watts.

[Dellboy218]

Your average 25000BTU air con runs close to 8kW

that would be a real energy guzzler! make that max 2.5kW for an old rattler

1 British Thermal Unit (Btu) = 0.0002928 kW

Indeed, but a modern A/C will pump about 3 times it's input power, so a 25,000 BTU unit will draw about 2500 Watts.

Indeed you are right, I recently scrapped an old machine which was closer to the 'official' figure than the 1/3rd, I was a little worried when I checked the current drawn hence it was scrapped. I presume somewhen they might redefine the BTU or introduce something else. Which makes yours a new(er) rattler not an old one!