Is my Hot Water Cylinder Coil holed?

[doitall]

Thats why he's testing the temperature, if its warm then it has to come from the cylinder.

To be honest the water can't come from too many places unless something is connected wrong

 

[IanPlumber]

Hi all,
I am having a similar problem at home. Over the last few days my f+e tank has been filling with hot water.
I have tried several things but nothing has cured it.
I have a feeling that i may be a cylinder problem but am unsure.
What is the easiest way of telling if this is the case?
So far I have shut off the cold supply from my storage tank to the cylinder and ran the hot taps for a while until the water stopped. The F+E tank did not fill or empty.
It says on a sticker on the side of the cylinder " ???crificial cylinder with anode" (first part of the sticker is missing). Also it says on another sticker "Churchill 1.5hr recovery with gravity".
Not quite sure how these work inside so if anyone can enlighten me i would appreciate it.
The F+R to the cylinder are 28mm and there is a 22mm pipe from the return going to the F+E tank with the expansion pipe off of that.
The cylinder does not have a stat as far as i can see and i can't find a zone valve anywhere.
Please help as i am starting to run out of ideas here.

 

[Softus]

I have a feeling that i may be a cylinder problem but am unsure.
What is the easiest way of telling if this is the case?

Did you not read this topic before you hijacked it?

So far I have shut off the cold supply from my storage tank to the cylinder and ran the hot taps for a while until the water stopped. The F+E tank did not fill or empty.

Which goes to show why that's an inconclusive test.

It says on a sticker on the side of the cylinder " ???crificial cylinder with anode" (first part of the sticker is missing).

It probably says "cylinder with sacrificial anode".

Not quite sure how these work inside so if anyone can enlighten me i would appreciate it.

It has a coil. Read the Wiki for other details.

The F+R to the cylinder are 28mm and there is a 22mm pipe from the return going to the F+E tank with the expansion pipe off of that.

You might have a vent and a cold feed, but there's no such thing as an "expansion pipe".

The cylinder does not have a stat as far as i can see and i can't find a zone valve anywhere.

You could save yourself some gas/oil then, by fitting more controls when you replace the cylinder.

Please help as i am starting to run out of ideas here.

Have you searched the forum for people with the same symptoms? (I mean technical symptoms of the heating system, not the symptom of not reading things for yourself).

 

[Redhotferrari]

Guys, thats very much for all the posts on this on....

UPDATE.......................

Bit the proverbial bullet and changed the cylinder last wednesday, all problems seem to be solved, no more rising levels or overflowing.......

So is would appear all is now fine, apart from a dent in the wallet, not to mention 3 and a half hours to change the bloody thing! Not exactly the largest airing cupboard in the world!!!!

Once again thanks for all the advice.

 

[Softus]

...3 and a half hours to change the b****y thing!

So, you couldn't diagnose the fault, but you can change an indirect cylinder in 3.5 hours. Pull the other one.

 

[Redhotferrari]

Give me all the bits in boxes on a table and I could build a PC in about 10 minutes, does not mean I could tell you what is causing a blue screen crash.......

Time did not include draining, filling and bleeding system, literally just changing the cylinder...sorry to mislead you

 

[Softus]

Give me all the bits in boxes on a table and I could build a PC in about 10 minutes

That's just another lie.

Time did not include draining, filling and bleeding system, literally just changing the cylinder.

I already knew that it didn't include everything involved in changing a cylinder.

sorry to mislead you

Let's be sure of one thing - the only person you're fooling is yourself.

 

[Redhotferrari]

gonna let the 'lie' comment go. I am not bothered in your thoughts of me, but your diagnosis and plumbing tips are spot on, thank you

But I would like your expert opinion if you are happy to give it?

I cut the cylinder up out of curiosity to see if I could see the problem, once I had managed to get through the limescale build up!!! I cut the coil out at the connections and inspected it thinking I would almost see a split bearing in mind my F&E was filling up in less than 24hrs, but I could not see any thing! It did have loads of limescale attached to it, but I expected that.

Woud a hole to small to see still cause this type of problem? if so I am truley amazed.

 

[Softus]

But I would like your expert opinion if you are happy to give it?

Naturally.

Woud a hole to small to see still cause this type of problem? if so I am truley amazed.

In my experience the flow out of most worn out coils isn't dramatic, and the hole isn't large.

Imagine a hosepipe with a tiny jet of water escaping through a pinprick hole. If you could fill a milk bottle in 45 minutes from such a jet, then the same flow rate would fill your F&E within 24 hours.

 

[Redhotferrari]

When its explained like that it makes sense, the F&E is not that big after all!!

You prob cant really answer this, but does the manufacturing of the coil make a weakness in the copper that is not replicated in the making of the cylinder then? Obviously the cylinder and the coil is made at the same time and the cylinder was in near perfect condition. OR does the chemicals that is added to the CH system eventually eat away at the coil?

 

[Softus]

Hm. I guess you're asking why the coil fails before the cylinder?

Well, many cylinders do fail before the coil - it's a lottery.

However, the coil is subject to two effects that the cylinder isn't:

1. Wear by water abrasion
Water is circulating through the coil, and, ignoring all other factors, it's only a matter of time before it wears all the way through at the thinnest point. Cylinder surfaces suffer nowhere near the same amount of abrasion.

2. Electrolytic corrosion
It's a constant battle to lessen/stop the dissimilar metals (copper and steel) in an oxygenated electrolyte from removing copper atoms and depositing them somewhere else.

 

[hut27]

Hi, The coil would not have been made at same time as cylinder. Cylinder is constructed out of sheet copper, coil is made out of soft copper tube. We had a lot of perforated copper tube in the late 50s early 60s and had a meeting with manufacturers of tube and The Copper Development Association and were told its invariably caused by tiny specks of Carbon left on the inside of the pipe from the extremley hot extrusion process. Electrolysis then sets in around this carbon deposit. This Carbon should be removed by steam cleaning but sometimes a little gets missed. Regards,Hut27.

 

[littleleaks]

Should the f&e tank not be higher than the cws tank? At least thats what i was thought.

 

[seco services]

Should the f&e tank not be higher than the cws tank? At least thats what i was thought.

lower.

 

[kevindgas]

Should the f&e tank not be higher than the cws tank? At least thats what i was thought.

it actually doesn't matter so long as the F+E tank cannot leak into the CWS tank (have seen a few over the years) the overflow from CWS is sometimes piped into F+E which again is not good practice (and the other way is very very bad)