Plastic or metal?

[bazza40]

I was shopping for a new wall water heater yesterday. Looking at Panasonic and Mazumo?

The staff at Homepro were pushing the Mazumo? pretty hard. About the same price, 4000 baht. The Mazumo? internals had a copper water tank inside, whereas the Panasonic was plastic. The Homepro staff claimed the Mazumo? was more durable.

Any truth to this? I would have thought the Panasonic with plastic internals would be safer in the event of tank leakage resulting in a short circuit. The copper tank was assembled as a cylinder with two soldered copper ends. The plastic tank appeared to be a one-piece moulding.

The thought did occur to me the sales staff were pushing the Mazumo? hard because the commission was better, or a directive from management to clear that stock.

[lopburi3]

Suspect you are right - I have two of the new Panasonic models and highly recommend - it is the newest generation design and very waterproof/safe construction. But it also provides better heating than any other unit of same capacity I have used and much better water flow. And currently have 4 other Japanese name brands.

[lj cm]

I am sure it's the commission (or management).

On purchases in HomePro and other places, I've had the same experience, where they are very eager to sell a curtain Brand.

(And then I have been very eager not to buy that Brand.)

Btw; we have always been happy with Panasonic water heaters.

[noise]

I know not the answer, but you might google something like hot hard water, copper tanks and tubing, and plastic tanks and tubing. I would intuitively think the copper is better, maybe only because (a) my water heaters are copper and (b ) copper is used for safe distillation of potable liquids. Now people normally do not drink the hot water, so extended leaching from the plastic may not be an issue. But that will accelerate or suppress calcium deposits in the lines?

Edited November 3, 2015 by noise

[h90]

Panasonic is a well known brand. At same price go with the Panasonic.

[steven100]

I was always told to only buy the copper drum type as they would last much longer than the plastic inner.

[lopburi3]

I was always told to only buy the copper drum type as they would last much longer than the plastic inner.

Believe you were told that years ago? When the choice was copper or the cheaper aluminum/white metal heating tanks?

[steven100]

I was always told to only buy the copper drum type as they would last much longer than the plastic inner.

Believe you were told that years ago? When the choice was copper or the cheaper aluminum/white metal heating tanks?

yes possibly correct, also don't some plastics become brittle & crumble after years of use ?

I remember buying a unit 5 years ago and the sales guy recommended the copper .........

maybe the plastic is just as good now ?

[lopburi3]

Yes in years past there were two concerns - case being metal rusted out so plastic normally recommended - tank of cheap metal was not considered good as quickly became encrusted with lime and blocked so copper recommended.

But this Panasonic is a new generation type unit and replaces there older copper tanks if it looks like below unit.

[ignis]

I have the old type and been happy with 2 Panasonic water heaters, just yesterday replaced the shower head on one, that is with constant use for 12 years.... No idea with the new type..

would say the water flow appear to be less these days so maybe the old copper pipes are gummed up a bit. job to remember what they were like 12 years ago.

[lopburi3]

Are they Panasonic branded or the older National? Thailand was late to get the change to Panasonic models and we still have several National which work well (other than then on/off water flow push switch which never worked good with high pressure pumps). This type?

[ignis]

Are they Panasonic branded or the older National? Thailand was late to get the change to Panasonic models and we still have several National which work well (other than then on/off water flow push switch which never worked good with high pressure pumps). This type?

PANASONIC MODEL DH-3BS1M

[lopburi3]

Guess just showing my age again - seems like they just changed to Panasonic name here.

[rak sa_ngop]

I have the Mazumo silver model because it looks very stylish and matches my polished granite shower walls.

It seems to work well although the temperature control does not have much effect at lower levels, i.e does not increase in temperature progressively so either no heat or hot (but not too hot).

The other niggly thing is that the unit 'hums' with increased humming at hotter temperatures.

Not sure if the above is common to other units, but probably the best you can expect from a Thai machine?

[bazza40]

I know not the answer, but you might google something like hot hard water, copper tanks and tubing, and plastic tanks and tubing. I would intuitively think the copper is better, maybe only because (a) my water heaters are copper and (b ) copper is used for safe distillation of potable liquids. Now people normally do not drink the hot water, so extended leaching from the plastic may not be an issue. But that will accelerate or suppress calcium deposits in the lines?

Copper is used in the distillation of spirits such as whisky, brandy etc. because it reacts with any short-chain acids ( e.g. formic, acetic, propionic etc, )

and prevents these compounds from being distilled over, thus avoiding spoiling of the flavours. I have no idea how copper would influence scaling by calcium deposits. Scaling is more a function of water chemistry.

[dddave]

I've had an inexpensive Toshiba copper tank, wall unit for 10+ years now and so far, no problems. Gets almost no use except for cool season. During warmer months, water gets so warm in my apartment buildings roof storage tanks that it's unnecessary.

[TheCruncher]

The reason they change to the plastic tank is because it is cheaper than a copper tank.

Have you ever known some cost reduction to improve anything?

[kamalabob2]

Mazuma has a PC (company paid salesperson) in HomePro. That PC is partly paid based on sales. Panasonic might not have a PC. I've owned a Panasonic instant hot water heater mounted on the wall in a rental unit and it was very dependable. I currently own six Stiebel Elton 8000 watt under the counter multi point water heaters and they all have copper tanks. I also have Toshiba WH-6000MMP multipoint function hot water heater in a modest village house and it has given me the ability to heat water in a bathroom mixer tap, kitchen faucet and shower with one heater. I was able to safely use a smaller size Schneider Electric circuit breaker and 4.0 grounded electric cable for the Toshiba instant water heater, but a larger Square D circuit breaker for the Stiebel Eltron multi point water heaters. The OP might phone the posted "customer service" telephone number on the Mazuma box and see how well it goes in English and when they will come to his province to repair his Mazuma water heater. Then phone Panasonic and see how the warranty customer service is handled.

[Gonsalviz]

If there is a HOME HUB near you, you might ought check it out I find their prices to be lower.

[baneko]

Copper corrodes at such a slow rate that is negligible unless used with discimilar metal which may cause galvanic corrosion. I would also say it will hold temperature better dependent on its insulation. Plastic does become brittle over time. All items now become with a life expectency. If all were fullproof they couldnt sell another. Check the guarantee may help.