New Copper cylinder - Advice sought

glog

So my current copper cylinder has sprung a tiny pin hole leak on the shoulder of the top fitting.
The tank is at least 10 years old and we have well water.
So, i think a replacement is the best approach.

I have found out that the current cylinder has the following spec:
- 18" x 42 "
- insulated
- Rapid Recovery Coil (1 flow/1 return)
- Top immersion
- Bottom immersion ( i think there used to be a night meter, previous owner)

We use the immersion rarely, heating the water with the Oil boiler instead
The Night meter is no longer active.

With this in mind i'm thinking of replacing it with:
- standard insulated 42 " copper tank
- standard coil
- standard top immersion only.

Is there anything i need to look out for regarding this replacement?
Can i use the existing top immersion in the new tank?

Appreciate any input.
gLog.

John.G

glog wrote: »

So my current copper cylinder has sprung a tiny pin hole leak on the shoulder of the top fitting.
The tank is at least 10 years old and we have well water.
So, i think a replacement is the best approach.

I have found out that the current cylinder has the following spec:
- 18" x 42 "
- insulated
- Rapid Recovery Coil (1 flow/1 return)
- Top immersion
- Bottom immersion ( i think there used to be a night meter, previous owner)

We use the immersion rarely, heating the water with the Oil boiler instead
The Night meter is no longer active.

With this in mind i'm thinking of replacing it with:
- standard insulated 42 " copper tank
- standard coil
- standard top immersion only.

Is there anything i need to look out for regarding this replacement?
Can i use the existing top immersion in the new tank?

Appreciate any input.
gLog.

You need a 11" immersion, the old one, if side mounted probably isn't, its also >10 years old so probably makes more sense to install a new one. You could also consider installing a dual immersion 24"(or 27")X11" and just connect up the top immersion, you can always fit a sink/bath c/o switch later or when installing it, difference in cost between a 24" dual immersion and a 11" single is < €5, something like €26 vs €23. The only draw back is that a single will be 3 kw and the dual top element probably 2.5kw so a quicker heat up with the single but no big deal as you are only heating 30 litres or so.

glog

John.G wrote: »

You need a 11" immersion, the old one, if side mounted probably isn't, its also >10 years old so probably makes more sense to install a new one. You could also consider installing a dual immersion 24"(or 27")X11" and just connect up the top immersion, you can always fit a sink/bath c/o switch later or when installing it, difference in cost between a 24" dual immersion and a 11" single is < €5, something like €26 vs €23. The only draw back is that a single will be 3 kw and the dual top element probably 2.5kw so a quicker heat up with the single but no big deal as you are only heating 30 litres or so.

Thanks - The existing immersion is a top entry and is already wired for Sink/Bath.
TIH467 Dual 36"/11" Copper Immersion Heater & Thermostat
So i may just replace anyway with the same.
AFAIK the bottom immersion was used on a night meter so is probably wired on a different circuit. I will confirm that by checking the wiring.

One other question. There appears to be an isolation valve on the return of the coil. Using that and the water zone isolation valve on the flow , is there still a need to drain the heating system?

John.G

glog wrote: »

Thanks - The existing immersion is a top entry and is already wired for Sink/Bath.
TIH467 Dual 36"/11" Copper Immersion Heater & Thermostat
So i may just replace anyway with the same.
AFAIK the bottom immersion was used on a night meter so is probably wired on a different circuit. I will confirm that by checking the wiring.

One other question. There appears to be an isolation valve on the return of the coil. Using that and the water zone isolation valve on the flow , is there still a need to drain the heating system?

Probably no need to drain as long as the zone valve is holding tight, just close the return isolation valve which is actually a balancing valve, you might make a note of how many turns it takes to close, it might be 1 to 1 & a half turns open and after installing the new cylinder open this valve the same amount. Just crack open the top coil connection and then drain off the coil contents from the bottom connection but be happy that it stops draining after a few minutes which it should if both valves are holding.

Dtp1979

Don’t be overthinking it.
If you want the best of the best, get s stainless steel well master cylinder.
If you want to stick with copper, get a grade 2 Cyl

cnocbui

I have hard well water. My cylinder went fairly recently, so I replaced it with a stainless steel one. If you replace it with a copper one, expect to be doing it all over again in the future.

Dtp1979

cnocbui wrote: »

I have hard well water. My cylinder went fairly recently, so I replaced it with a stainless steel one. If you replace it with a copper one, expect to be doing it all over again in the future.

If your stainless steel cylinder isn’t a well master or glass lined, then you can expect the same too

cnocbui

The copper one lasted 19 years. The new SS one will be the next owners worry some decades in the future. It was supplied as suitable for hard well water, so fingers crossed.

Dtp1979

cnocbui wrote: »

The copper one lasted 19 years. The new SS one will be the next owners worry some decades in the future. It was supplied as suitable for hard well water, so fingers crossed.

It’s not the hard water that erodes stainless steel. It’s the well water itself. There’s stainless steel and then there’s well master cylinders made of stainless steel

John.G

cnocbui wrote: »

I have hard well water. My cylinder went fairly recently, so I replaced it with a stainless steel one. If you replace it with a copper one, expect to be doing it all over again in the future.

Replaced relations electric immersion only recently due to build up of limescale, strangely enough the heating up time of the cylinder seemed the same but I suppose the element would just keep increasing its metal temperature until it just burned out, the reason I changed it was because of the loud "singing" sound when the sink immersion was on. The coil is still heating up the water in a reasonable time after 11 years and didn't look anything like the condition of yours, post #668.
https://www.boards.ie/vbulletin/showthread.php?t=2057088802&page=45

cnocbui

The immersion element has a thermostat - usually set to 65°C - so it's not going to keep increasing in temperature much beyond that. I have had copper clad immersions go, but it was due to corrosion penetrating the copper and allowing water in to the element and tripping the RCD, rather than burn out. I switched to SS jacketed ones.

As you can see from my photo, the buildup of scale on the element and coils is not infinite. It gets to a certain thickness and then flakes off. The most notable improvement with the new cylinder was that it seems to heat up much faster via the main coil than it used to.