Installing water heater

[Aforek]

Hello, 

I intend to buy a water heater  and install it in one of my bahtrooms

first, do you have a brand to recommend ? I see prices on Lazada, and there are many in range 2800 -3000 bahts; inexpensive but are they good ? 

I have read that water heater can be dangerous ( electrocution ) , so I shall ask a Thai man who worked for me already and who seems to be a good professional electrician to install it for me 

are there any special precautions to take ? last year, this electrician installed a new Schneider electric meter following the advices I received on this forum ( I don't rembember the technical name, but it was from the recommandations of Crossy ) 

thanks 

 

 

 

[Peterw42]

You have answered your own question, a quality unit (with earth leakage ELCB/RCD protection) correctly installed by a professional electrician. Maybe an outlet like homepro where they sell known brands

Edited July 30, 2020 by Peterw42

[scubascuba3]

Have a look online at powerbuy, good choice there and prices. I like Japanese products as very reliable, all are in the similar price range. Usually 3500 watt or 4500 watt on offer, 3500 watt seems perfectly fine in Thailand

[bankruatsteve]

If you stay within 4.5kW, using a separate circuit from your CU (if possible - but in any case) run 2.5mm²  wires minimum for L,N,E.

[johng]

I would  recommend a unit with a copper heating tank  and as few internal circuit boards as possible.

This one Joven 2000   lasted many years until the water flow sensor sprang a leak..no spare parts too old !!!

 

I bought 2 cheapo  "Haier"   all singing and dancing heaters with 2 circuit boards inside  they both failed within a few months   but  where fixed under warranty.

 

 

[lopburi3]

Have had any types over the years and like the current Panasonic models very much - cheap/safe/very good water flow and easy to install and use.

Be very sure ground is attached.  And best to have upstream RCCD as well as the built in unit to provide protection for fault to line into the unit (the Panasonic model is well protected by plastic but some others are not).  As said use 2.5 wire.  3500 should be fine for Bangkok/south but in upcountry mountains 4500 might be better - normally you can slow water flow to make hotter on coldest days.

[Metropolitian]

There's now a Homepro Expo going on in Muang Thong Thani (Nonthaburi province, near Bangkok.) . 
If you do live not far from there, it's worth the visit and you can see the brands they offers (and inside the heaters).

They offers the heater with promotional prices.

 

http://www.impact.co.th/index.php/visitor/event_detail/en/36902/homepro-expo-ldquo-happy-home-healthy-living-rdquo

Now till august 2nd.

[moontang]

On 7/30/2020 at 10:57 AM, lopburi3 said:

Have had any types over the years and like the current Panasonic models very much - cheap/safe/very good water flow and easy to install and use.

Be very sure ground is attached.  And best to have upstream RCCD as well as the built in unit to provide protection for fault to line into the unit (the Panasonic model is well protected by plastic but some others are not).  As said use 2.5 wire.  3500 should be fine for Bangkok/south but in upcountry mountains 4500 might be better - normally you can slow water flow to make hotter on coldest days.

That is the one I bought. The 3500w Very reliable, and well designed to keep water out.  Can run it on a 20 amp circuit and 3 x 2.5 wire (if you can find 3 wire, lol.).   Bought mine on Lazada for about 2300.

[sometimewoodworker]

8 minutes ago, moontang said:

That is the one I bought. The 3500w Very reliable, and well designed to keep water out.  Can run it on a 20 amp circuit and 3 x 2.5 wire (if you can find 3 wire, lol.).   Bought mine on Lazada for about 2300.

It will only need a 16A breaker and the cable only needs to be 2.5 x 2 & 1.5 earth.

[moontang]

3 hours ago, sometimewoodworker said:

It will only need a 16A breaker and the cable only needs to be 2.5 x 2 & 1.5 earth.

Most electrical codes require the ampacity of continuos loads to be increased by 25%.  3500÷240x1.25=18.xx.  I am not an electrician, but neither are the people working on electrical appliances, here.  Would be glad to look at someone else's calculation method.

 

The guy from Siam TV that had to redo my install six years ago on a 4500w, did give me a good tip, and that was to turn it off with the water running, and cool it down for 5 seconds or so...not as necessary on the 3500, but I still do it.  It prevents a sizzling effect if it is going to be used before it would normally cool off.  He also used the instruction booklet guide on how to precisely cut and strip the wires, which I did two years ago on the Panasonic, and it fit almost as good as OJ's glove.  The problem with the Siam TV install (free) was he stripped the jacket off the wire to slightly before it entered the unit, and did not install the rubber ring, leaving 2-3 mm of daylight around the wire.  And that was an Electrolux that wasn't nearly as well designed with safety features.

[sometimewoodworker]

28 minutes ago, moontang said:

I am not an electrician, but neither are the people working on electrical appliances, here.

Really??? Your knowledge is from?
 

The 16A breaker will happily allow a current draw well over it’s rating for longer (unless you are a teenage girl ???? ) than any user is likely to shower, and the shower temperature it unlikely to be set to it’s maximum for most of the year. So with all of that a 16A breaker is easily big enough.

[moontang]

4 minutes ago, sometimewoodworker said:

Really??? Your knowledge is from?
 

The 16A breaker will happily allow a current draw well over it’s rating for longer (unless you are a teenage girl ???? ) than any user is likely to shower, and the shower temperature it unlikely to be set to it’s maximum for most of the year. So with all of that a 16A breaker is easily big enough.

But not code compliant.  "Likely," "unlikely"...yeah, right.

Edited August 1, 2020 by moontang

[sometimewoodworker]

1 minute ago, moontang said:

But not code compliant.  

55555555555555555

you are sure?

 

[scubascuba3]

anyone know why a water heater would take longer to heat the water than usual? my previous 3500 watt heater did it pretty quick, this one pretty slowly, both Japanese and 5+ years old so I'd expect still to be good

[johng]

Cooler water in and /or higher pressure/flow rate assuming both heater are the same wattage.

Edited August 1, 2020 by johng

[moontang]

14 minutes ago, sometimewoodworker said:

55555555555555555

you are sure?

 

80% Safe Maximum Rule..16 amp breakerx240=3840 watts..but the safe maximum is 3072 watts..avoiding heat for safety, efficiency, and risk of fire.  And if you are in a house in Chiang Mai, that thing will be on max most of the year.

[moontang]

25 minutes ago, scubascuba3 said:

anyone know why a water heater would take longer to heat the water than usual? my previous 3500 watt heater did it pretty quick, this one pretty slowly, both Japanese and 5+ years old so I'd expect still to be good

How many amps is your circuit and what size is the wire?  

[sometimewoodworker]

14 minutes ago, moontang said:

if you are in a house in Chiang Mai, that thing will be on max most of the year.

If you use a water heater that low powered up there then you either like cold showers, have no money or no common sense.

[scubascuba3]

9 hours ago, moontang said:

How many amps is your circuit and what size is the wire?  

I don't know but i wouldn't be surprised if the wrong size wire was used

[Crossy]

11 hours ago, scubascuba3 said:

anyone know why a water heater would take longer to heat the water than usual? my previous 3500 watt heater did it pretty quick, this one pretty slowly, both Japanese and 5+ years old so I'd expect still to be good

 

Low supply voltage would cause this effect as well as the reasons noted by others. Heating effect follows the square of supply voltage so a small reduction in voltage leads toa much larger reduction in power.

 

[Crossy]

 

A while back I did this plot of heater power vs supply voltage.

 

[Crossy]

Since someone has called me out that the above plot "looks linear" here's a plot right down to 0V.

Note that at 50% supply voltage the heater power is 25% of rated.

 

[RichCor]

9 hours ago, Crossy said:

A while back I did this plot of heater power vs supply voltage.

...there are times that make me think Crossy may have vested interests in numerous anonymous Automatic Voltage Regulator companies

[dddave]

I had a 3500 watt Toshiba for 10 years that worked without fail.  I replaced it just because I thought 10 years was long enough and replaced it with a Hitachi 4500 watt unit.  Nice unit but it actually makes the water too hot, even at it's lowest setting.  I have very good water flow so that's not the issue.  I had to run a second cold water supply line into the shower hose to cool it off enough to be comfortable.

[kamalabob2]

If the OP or others are installing the multi point 8000 watt water heaters, they may consider the advice I received from Stiebel Elton:

For your question, the answer is in the red text

 

For 8000 watt multi point Stiebel Eltron

 

1) What size electric cable is best from the load center to each heater?     2.5mm or 4.0 mm or 6.0 mm

 // 10 mm is the best for 8000watt multipoint unit , If choose 6 mm is  ”just” ok

 

2) What size circuit breaker? // 40 amp

 

3) Should this breaker be a RCBO breaker or normal breaker? // RCBO breaker

 

 

Safety is my #1 concern. // Stiebel Eltron, too J

 

 

Further information you require, pls do let me know.

 

Best regards,

     Vivi

[Aforek]

I have bought a Stiebel eltron 3500 w; an electrician installed it and it's ok 

what regular maintenance is there to do ? every year, by an electrician ? 

Thanks 

[bankruatsteve]

10 minutes ago, Aforek said:

I have bought a Stiebel eltron 3500 w; an electrician installed it and it's ok 

what regular maintenance is there to do ? every year, by an electrician ? 

Thanks 

None that I am aware.  Do push the "Test" button once in a while and then re-set.  Some have suggested running vinegar through to remove lime scale.  It seems they either last for a while or they don't.

[moontang]

Some have a removable, cleanable screen at the inlet.  Almost looks like a plug.

[Crossy]

2 minutes ago, moontang said:

Some have a removable, cleanable screen at the inlet.  Almost looks like a plug.

 

And others hide it as the inlet sealing washer so you have to take off the feed pipe to get at it.