Thread: Instantaneous Electric HWS

Mate to be honest I wouldnt have a clue, Ive never had to replace or repair one, removed a few to make way for storage or instantaneous gas. The stiebel ones have a fair reputation, I dont think Hocking even exist anymore. Im sure one of the other fellas will know.

I personally wouldn't get one unless there's a good reason why you can't use off-peak electric storage, solar, gas, heat pump etc. All of those will be a lot cheaper to run under typical domsetic circumstances and don't impose the nasty (and polluting) peak power demands on the grid that an instant unit will.

Am considering everything Smurf, but didn't want to burden everyone with the old "What sort of X (in this case X being "Hot Water System") should I get?" type question at everyone. You make some valid points, so for what it's worth, current situation is small electric storage system in corner of kitchen cupboard in an upper-floor flat. Unless you've been in such a flat (or even in the flat below) when one of these babies let's go - trying to come to grips with the damage to the cabinets, carpets, and sometimes even ceilings - it's hard to otherwise understand just how good it would be to get away from Storage Systems altogether...

For certain particular reasons, Heat Transfer and Solar are definitely not options, and there is no gas currently on site. I have a short list in mind, but for one reason or another, none of them are either easy or inexpensive.

The subject of this particular thread - Instantaneous Electric - is one of those options. It's principal advantage is that the water path is manufactured entirely from copper tubing, and thus not dependent on the maintenance of a Sacrificial Anode as is the case in a steel-tank Storage System. At present, due to the location of the System, I can't even get the Sacrificial Anode out to check it. Principal disadvantage of Instantaneous Electric is that Single-Phase versions are gutless. Would therefore have to run Three-Phase up to the flat...

Still thinking, but nothing's easy, you see...

Best Wishes,
Batpig.

You might like to try;

Hocking Water Heater Co Pty Ltd

<table cellpadding="0" cellspacing="0" width="100%"><tbody><tr><td class="text" valign="top"> 9 Yallourn Street
Fyshwick ACT 2609
Telephone: (02) 6280-4177</td></tr></tbody></table>

or this web link;


http://www.wilsonhotwater.com.au/htm...antaneous.html

You'll just find that the cost of getting 3 phase in to a flat is prohibitive. I once had a builder provide one to me to fit in a small flat, I thought not about the electric side of it as you do, then the sparky hit the roof about bringing 3 phase in from the board 2 floors down. Might not even have it in the building.
Not sure about that Hocking address in ACT. They used to be in Marrickville but the shop is vacant. Their instantaneous is still in the pricelist of Reece and Plumbers Co-op so maybe they moved down there.

I can see your reasons for wanting one. There's nothing "wrong" with instantaneous electric as such, just that if you had gas or a suitable location for off-peak storage etc then those would be a better option.

One way to make the storage unit safer in the event that it fails is to have a "safe tray" under it. If it leaks then the water drains away. If a drain can't be installed then there is a float valve type of unit (I assume that's how it works) commercially available that cuts the water supply to the heater if the tray starts to fill with water. Both the trays and float valves are easily available and not too expensive.

I'd certainly be checking the availability of 3 phase power and the cost of getting it installed before buying an instant electric water heater. It could cost quite a bit depending on circumstances.

Dear Smurf,

We could get the 50L electric storage onto a copper tray in the current under-bench location, but the problem is running the drain away. You see, even though it's not far from the sink waste, the lack of head height above the HWS in it's installed position means that it can only be slid into the corner on it's tray, rather than dropped into an already-positioned tray that has been plumbed up to the waste pipe. So plumbing from the tray is effectively not possible.

Just by the way, it might be worth pointing out to you that the little 50L storage units that you find in a lot of flats and units are not actually connected to off-peak, because they are too small. Rather, they are in effect a sort of hybrid "instantaneous/storage" system, in so far as the single-phase power available to them (normally 3600w on a dedicated 15A circuit for the HWS) is just too gutless to heat the water up by itself on demand, so it is augmented by the "buffer" created by 50L of stored water that has already been heated before the tap is turned.

The float valve for the tray which you have described sounds great. I had no idea they even existed. But there are other issues...

You see, our illustrious State Government up here, in it's infinite wisdom, has deemed that from the year 2010 onwards, it will be illegal to sell or install new electric Hot Water Systems. They want us to swing over to more Greenhouse-friendly methods of water-heating. On the face of it, that sounds great, but me-thinks a couple of things are going to happen with our utility bills once this has occurred:
1) The cost per unit (ie. c/kWh) will simply just increase at a greater rate than consumption decreases, so that the new privatised provider companies that now bill you up here will continue to show year-on-year profit increases to shareholders.
2) The combined cost of gas and electricity bills will end up far exceeding the previous cost of the single electricity bill alone. There is a lot of devious psychology in having the energy bill split... Why do all the Insurers and Transport Departments (ie. Rego) now offer monthly repayments that add up to more than a single yearly instalment?
A rhetorical question: Why in their new policy does the State Government not offer the option of retaining an electric system if the address in question is energy-rich (ie. generating more electricity - via solar panels on the roof - than what it is consuming)? Why - because they would have to pay you for electricity, rather than have you pay one of their political-donation-making energy-providers for natural gas...

Anyway, the long and the short of it is that it looks like electric will disappear up here after 2010. Why, then, am I interested in instantaneous electric? Because it has superior life-span to conventional storage due to the lack of a welded-seam steel tank. Might just get me over the line until Solar Cells start appearing on roofs in a big way. Only problem - single-phase versions are gutless...

As stated in an earlier post, Heat-Transfer and Solar are not options. Small 50L in Stainless might be, though, but they are very dear, and you never know when the Government might also ban the sale of the bluddy replacement elements for them...

Gas is ticking away in the back of my mind, even though it is not currently running into the site. Apart from this, one of it's big problems from my perspective is that there is not enough room out on the landing to do gas storage, which means I would have to do a small instantaneous unit hanging on the wall. The chief problem with this - theft... The chief way around this - an internal Rinnai unit with flueing, but it would be as expensive as hell to do, as you can imagine...

Like I said, nothing's easy...
Best Wishes,
Batpig.

Hotman instantaneous hot water system.

This was the unit I purchased off Ebay.

Made by Semens, they seem to have sold a few on ebay about a year or so ago, really made for the US and Canadian market going by all the instructions.

It works off single phase and can draw a massive 60 amps.

Two circuits one 40 amp the other 20 amp.

I intend to modify the 40 amp circuit so it only pulls 20 amps.

On very cold water it produces very hot water with 60 amps, so hoping 40 amps on two circuits will do the trick.

40 amps on the one circuit require 10mm2 wiring. So figured 40 amps split over two circuits with 25amp circuit breakers should be better.

The cost was $157 including delivery.

I only use it for a kitchen sink so not used too much.

The only other I know of is the one you mentioned.

Good Luck

Pulpo

Batpig,
don't know if it will fit but you can get a Saxon copperflow HWS which has a copper tank. Smallest size is 70 L though. I know of several of these systems which are well over 30 years old and still running fine. It's been a requirement in Qld for quite some time that any internally mounted HWS is on a safe tray with a drain.

Mick

Dear Pulpo and Mick,

Thanks for the pointers. Instead of replacing the current HWS now, I am swinging towards the idea of putting the present 50L electric system back into the new kitchen cabinets, but only after first modifying the pipework behind to make the whole setup a little bit "futureproof", by way of perhaps chasing a pair of branch pipes up the back of the wall behind the rear of the new carcasses and tiling. That way I will be able to quickly install something instantaneous - gas or electric - when the 50L lets go, without having to pull out the new cabinets, or rip off any new tiling. The need for quick replacement in a non-electric-system future, without pulling out/up any new cabinets or tiling is really central to the whole issue. Only thing is, don't know exactly where to terminate the said pair of pipes - inside or out - because the wall is cavity brick. Inside termination would most easily and cheaply suit an instantaneous electric system if the current 50L let go before 2010, but external termination would better suit an instantaneous gas unit if I wanted to avoid the hassle of "flueing" the thing to the outside, if the current 50L let go after 2010.

Mick, if I did end up going the way of a longer-life 50 or 70L (ie. something electric that will still do the job on single phase), there is a company down south called Edson that do a little stainless-steel 50L that has a 20 year guarantee on the cylinder. They are very expensive though, and they don't have a distributor up here. I am also worried about the replacement element situation as time rolls on post 2010. Something instantaneous would also free up a bit more space in the kitchen cupboards. But the concept is still on the radar...

Thanks both,
Batpig.

HI BP,

I want to second Micks recommendation of a Saxon system - no dumb sacrificial thingo - no leaks - just continuos dependable hot water for years and years and years.

As I undertsand it you are in a block of flats - to get an instantaneous electric hot water system you will need a fair $ amount of work on mains cabling.