Are copper HW cylinders a thing of the past?

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rob_man, Dec 8, 10:15pm
I just bought a Rheem cylinder and it's vitreous enamel on steel. What's the story!

raven71, Dec 8, 11:18pm
Are you sure that's not just the outer wrapping!

farwest, Dec 8, 11:20pm
Low pressure cylinders are still copper. For mains pressure you're better with a stainless steel cylinder (I don't think Rheem do them).

trade4us2, Dec 8, 11:37pm
I install plastic ones. They keep springing leaks!

rob_man, Dec 9, 3:01am
It does appear to be enamel over steel. I'll know when we pick it up.

cowlover, Dec 9, 4:35am
So you have bought a Mains pressure cylinder rathr than a low pressure cylinder.If its enamel dont drop i cause that will crack the enamel and then its useless.

cantabman1, Dec 9, 11:22am
To answer your question, I really dont know! but a plumber might.
I can tell you that Hot Water Cylinders use up 40% of the monthly power bill which is a bloody lot, so any ideas to save money in this area would be worth considering. Solar,Rheem,wetback; anything to save $$$.

lythande1, Dec 9, 12:07pm
Yes copper is still used.
Some don't though. The enamel Rheem are not a good idea.

wunderbar2, Dec 9, 3:07pm
Enamel HWC are a"cheap" way to build HW cylinders . Manufacturers love them because it meansthey can sell you another onea few yearsdown the track . Now like someone said - transport one of them " horizontally" instead of standing up = and your warranty is gone out of the window ! because it can crack the liner in the inside . Thats usually the reason when those things start leaking after 2-4 years ( because the guy that dekiverd it cucked it in the back of his van.Besides that maximum temperature they can Handelis 72C centigrade - so they are no good for wetbacks or solar systems or if your Elements goes"woffti" and boils the water in your HWC . Apart from that they are cheap as chips .( Don't Worry , but having a strong religious believes helps ). (:-)( just kidding )Look if you buy a HWC get a copper one for low pressure setupsand if you need mains pressureuse 2mm thick stainless steel Cylinders if you can ( they are as solid as ) yesthey do cost a bit more - but replacing HWC is also an expensive Hobby .
How do i know !, well I sell those things

studio1, Dec 9, 4:12pm
There is a little-known issue with enamelled-steel hot water cylinders but it causes them not to last as long as they should.
It's called a sacrificial anode - much like what you have on a boat, or attached to an outboard motor.
The ones in the cylinders are in the form of a long rod which is screwed in from the top. If you have a look you'll see a cap or grommet in the centre of the top of the cylinder.
Take this out and you'll see a brass hexagonal nut. Undoing this and lifting it out brings the rod with it.
The rod should be replaced every few years, or the life of the cylinder will be greatly reduced.
The majority of plumbers don't even know this sacrificial anode exists, much less where to buy a replacement one from.
Naturally, when the cylinder starts leaking (because the steel lining has been corroded away) they are more than happy to sell you a new one.
Replacement anodes are available from the manufacturers of the cylinders and can be ordered through any plumbing outlet.

farwest, Dec 9, 4:15pm
They crack inside if transported horizontally because they have an anode dangling from the top, which can touch the enamel if not kept vertical. This anode is to prevent rusting of the iron if the enamel is holed.and it doesn't last forever. It may need replaced after 5 years or so.

farwest, Dec 9, 4:18pm
A cylinder with a stainless steel tank costs a little more, but doesn't have the same corrosion potential.

mabeyc, Dec 9, 6:44pm
We have gone through 6 elements in our stainless-mains pressure-wetback cylinders in the 2 years that it has been in. Turns out our bore water is not too good, and since it won't react with the stainless, it reacts with the element. The plumber & electrician are now muttering about a DIY sacrificial anode, either way the wetback has ended up being quite expensive.

elect70, Dec 9, 10:32pm
Wunder bar is right,its glass lined& steel shell , cheap . Cant beat good oldthick wall copper.I replaced mine 3 years ago with newECon oHeatcheaper thean rheem & far better quality, didnt like the idea ofglasslining .

argentum47, Dec 10, 12:46am
Check your PH level . ( water ) that may be the Gremlin - or a pretty high mineral content in the water.( which is a major problem inBalclutha for example

wunderbar2, Dec 10, 12:55am
To add a small comment onto the above .
When you buy a new HWC - try to avoid the" How much $ " question in the first sentence . (:-)I get that a lot : goes like that :
Hi Mate , I am after a new180L HWC - How much can you do it for !
I usualy say : No problem - how long do you want it to last !. (:-)

The reason is this : They all look pretty round on the outside , and come h buffed and polishedas well . Thats what you see . The interesting part is on the inside of them . Cut them openand you will findsome stainless steelCylinders are paper thin = 0.4mm in thicknessand othersare 1mm / 1.5mm /1.6mm /1.8mm and even 2mm thick . Here is the interesting part of it all . the thicker the stainless steel is , the longer they tend to last you , but the more they also will cost to make .And as you knowreplacing HWC is quite an expensive hobby - ( + the Plumber ) so you dont want to do that too often . (:-) if possible !

cantabman1, Dec 10, 1:52am
I have learnt something new today about these cylinders. We have a very old one from when the house was built in the 50's, about a 30gal tank. When the new wetback log burner was replaced last year the plumber was trying very very hard to upgrade us to a new one but we said no as what we had was ok. Thank god for that as im sure as, we would have ended up with what you described.

wunderbar2, Dec 10, 3:35am
Yepthey dont make them like this anymore !Yours got made as copper was still cheap and Plentiful - the only wayto get anything as close as possible ( what you have now ) is to grab a medium pressure HWC bit still run it as a low pressure Cylinder ( they use a thicker gauge copper in them ) and if the water is not all that brilliantyou also can pop a protective layer in it as well.But be prepared to keep an eye on your HWC - it is getting on a bit .(:-)I think the oldest one I replaced so far was about 49 years old. most of them go after about 30-35 odd years where they spring a leaky leak

rsr72, Dec 10, 1:53pm
-.Cancelled your order yet!

supernova2, Dec 10, 10:12pm
Before we pulled out our mains pressure gas rheeme I rang them about the annode.The dud said he didn't think it would be available as he hadn't heard of the model number (quoted off the label) and it wasn't worth replacing it anyway as undoing the cap would probably wreck the lining.

Graet aftersales service and confidence in their product - not!

elect70, Dec 10, 10:23pm
Smiths Elements make an "incalloy '1 forhard wateri put them inforbore waterhouses, where ordinary have lasted less than 5 years .n 10 years havent had to replace any incalloy ones

rob_man, Dec 10, 10:34pm
Thanks for all the replies, I'll have to run with it now and hope for the best. Amazing that something so fundamental can change without the general public muttering about it.

aredwood, Dec 11, 1:28am
The short answer - because people want mains pressure. A copper cylinder would have to be ridiculously thick to handle mains pressure. That's why they are all enamel steel or stainless steel. Otherwise youneed a Hunson, or an elephant HWC. They are a tank with a very big coil of copper pipe inside. With mains pressure water going through the coil and low pressure in the tank itself. Problem is they cost heaps.

wunderbar2, Dec 11, 2:14am
To add to the message above -
Elephant Cylindersare a old fashiond way to getmains pressure out of alow pressure HWC ( however saying that there are a few good applications for that particular HWC ). The Coil in those Cylinders is about 60m long !Now next time you go to bunningshave a look what 5m of copper pipe costs you . then times it by 6and that will give you a ruff Idea of how much just the coil will cost youif you buy one of those Cylinders + add the cost of the HWC as well( that was just the price for the coil ) . you just worked out .

trade4us2, Dec 11, 7:02pm
But they don't NEED mains pressure. A shower and all appliances are quite happy with an ordinary low pressure cylinder, if that is installed on the same floor as the shower.