Joven Vs Stiebel Heater

[longball53098]

Hey All,

I have been trying to decide what brand and size water heater to use for our new bathrooms (2) and also one for the kitchen sink. Someone suggested a brand (Joven) I never looked at before and have no knowledge of. I am skeptical of this brand from Malaysia.

The kitchen sink unit I will purchase a known brand in a smaller wattage not an issue. But the bath unit is where I have questions

I thought I was sure I wanted a bigger model of Steibel-Eltron specifically the DHF 13C which is a 380 volt 3 phase unit. This unit should supply plenty of hot water to at least 3 points at the same time. I emailed the Stiebel office here in BKK explaining my needs and over the course of a few emails the rep pointed me to this model as one best choice. I have emailed again about my questions but thought I would post here to the field of experts and see what you all have to say.

I am still pretty convinced this unit will serve my needs for several long years and many showers. But a point about this model was brought up and I cannot find an answer to this question?

Many if not all of the heaters for showers have the safety device built in known as the ELCB. It has been recommended to add a RCCB device in the consumer panel for added protection even when a heater has the ELCB.

I notice the DHF model does not have this and the installation manual does not suggest installing one. Being a novice DIY electrician I am in a confused state here. Due to this model requiring 3 phase power does that change the need for a ELCB or RCCB? I know an earth wire should be provided as well as the 3 phase power but what about a safety RCCB?

I guess I don't understand something here.

Can one of the experts in the sparkie field shed more light on this, please?

[Gary A]

My opinion is that other than the on demand hot water showers the on demand heaters are a royal pain. You NEVER get the right temperature mixture. If you want several different hot water locations, the best answer is a tank type heater. People will tell you that they are not as efficient as the on demand heaters, but I disagree with that. They keep the water hot and the wiring required is much easier to deal with. There is no need to string heavy cables with many breakers to every point. Tank type heaters do require an intelligent plumbing design so the heater is fairly close to every hot water location.

[Crossy]

You should use a 3-phase RCBO (that's an ELCB / MCB combined) if you can get one, otherwise a 3-phase ELCB and MCB will be needed and a good ground is vital.

Any reason you didn't opt for one of the electronically controlled units (DHE series), which allow you to precisely control the water temperature rather than the off-half-on control of the DHF ? They also remove any danger of scalding

The DHE can also take pre-heated water from your solar set-up and save money on juice

As noted by Gary, powerful instant heaters can be a pain to get right.

[Crossy]

Just to clarify the above.

If you already have a 3-phase ELCB / RCD / GFI you don't need to add another, just run the heater from the existing via a 3 pole MCB. Check the rating of the RCD and MCB and verify the cable size for your monster heater

3-phase RCBOs seem as common as hens teeth (and twice as expensive) so forget that idea

Important Note do NOT attempt to use 3 single phase MCBs or RCDs, it is vital for your safety that only proper 3 or 4 pole units are used.