Usually it is plastic insulation to cover the copper tank. Seldom see pure plastic heating tank.

see 5:35



see 4:16


This post has been edited by ceo684: Mar 10 2021, 08:35 PM

Nonstandard use with an external water pump that is above the spec of "max water pressure" supported by the WH can cause this issue.

The top part and bottom part is not actually one piece. Usually either glued or o ring or crimped to the lower part. Lower part is usually nylon only, for more electrical isolation.

So if I obediently use back its ori parts should be OK right?

I have never heard of Heating tank made up by plastic tank,,may be it is some kind of fiber glass, ABS, ....

Normally heating either made from stainless steel or pure copper, in IWH could be steel....

The pressure must be very huge in order to burst a heating tank !!

They is 1 key safety device attached along the heater, PRV ( Pressure release valve, or TPV ( Temperature Pressure release valve ).

This could prevent the case like heating tank burst..

Firstly is your Instant Water Heater come with internal pump ?

2nd, is your incoming water pressure super high ?

It is not easy to have element tank burst in normal operation

OR may be it is tank leaking with crack line ?


rdgs.

there is no pressure release valve in instant water heater.

it is designed in such that the outlet is never restricted or blocked.

hence there should not be any high pressure in the tank

Under normal circumstances it should last 10 years easily (w/o additional external pump). If using external pump need to check the pump's pressure doesn't exceed the capability of WH (max pressure it can sustain).

After 20 years I replaced the head and hose for my National 1997 era heater with Pana parts, coz of limescale affecting water pressure. Also condo mgmt replaced whole building piping and restored the pressure to pretty good level (as the original iron pipes all rusted internally)

This post has been edited by ceo684: Mar 11 2021, 01:52 AM

OK, that sounds convincing.
Thanks for your kind advice as you always give.

delete, duplicate

This post has been edited by wailing81: Mar 11 2021, 08:21 AM

hi, it is DSK38ESSMB.

ya, probably my inlet pressure is high cause i added a pump for the whole house.

the stopcock is at outlet as i connect it to a mixer type 3 way water outlet

no, without internal pump.

yes, incoming water pressure high.. but not until super high..

i had 2 unit of same model, one is burst and another one is fine.

That’s the problem.

The outlet should never be restricted.

It is in the manual.

OK, this is the model I'll be getting.

I guess you know what's the issue now...

Most welcome

You mean this one? http://toshiba.com.my/waterheater/dsk38s5mw.html#tab
Max inlet pressure 0.3MPa = 3bar

I think this one. http://toshiba.com.my/waterheater/dsk38es3mb.html

mine without pump...

no idea how much the pressure my pump pumping... never measure...
however will close the inlet valve and only open it during shower.

at the end, any water heater can resist high pressure?

Get Joven, nuff said.

If your water pressure is that high that it can cause the tank to burst, then this Toshiba 3800W heating element should not be hot enough for u.

Higher water pressure = faster water flow = shorter contact time between heating element and your incoming water = lesser temperature rise between inlet and outlet

For high water pressure household, better to use storage water heater, but also try not to go above 5 bars. If u don't want to use those that is installed above the ceiling, CENTON has one model called Nautilus Series that is meant to be installed below ceiling, with a smaller 20 litre capacity.