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brian_mk

I need to replace a leaking hot water cyclinder.
So far I've contacted about 4 plumbers but none have got back to me, so I'm considering tackling the job myself.

hw_cylinder.jpg

I have bought a drop in replacement cylinder with connections in the exact same positions.
I'm hoping to re-use the existing immersion heater as it has never actually been used.

My question is...

Will there be enough 'give' in the pipework to allow me to remove the old cylinder without cutting pipes?
As far as I can see, it means lifting the hot water outlet pipe up by about 1" to pull it out of the compression fitting to allow the cylinder to be slid to the right to remove the pipes to the coil. The horizontal 22mm section of pipe is about 20" long and the fittings are soldered.

The cold feed to the right has a conex conector at the top of the photo just below a gate valve.
You can't easily get to the elbow fitting at the bottom right of the cyclinder.
I'm hoping there will be enough give in the pipework to pull the cold feed pipe down and out of the compression fitting.
 
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It is good practice to fit cylinders on a flat ply base rather than bearers so the cylinder is fully supported. The risk of condensation below on is virtualy non existent if the cylinder is in use.

Bearers are the cause of a high number of cylinders failing as the movement due to expansion and contraction eventually rubs through at the point of contact.
If the cylinder is fully supported the pressure is spread across the full rim.
Next time you remove one that has just been sat on a chipboard floor have a look at the ring that has been worn into the board due to thermal movement.

Years ago we used to mount the cylinder halfway up the kitchen wall sitting on a bit angle iron or 1" mi cut into the brickwork across a corner. All the old heads knew the cylinder would fail at the point of contact so would place a bit sheet lead on the bar to help extend the tanks life.

Just not so common sense really.

Btw pet cocks should be banned but thankfully up this way the standard practice for a cylinder drain off is a sludge cock piped to outside.
 
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tamz said:
It is good practice to fit cylinders on a flat ply base rather than bearers so the cylinder is fully supported. The risk of condensation below on is virtualy non existent if the cylinder is in use.

Bearers are the cause of a high number of cylinders failing as the movement due to expansion and contraction eventually rubs through at the point of contact.
If the cylinder is fully supported the pressure is spread across the full rim.
Next time you remove one that has just been sat on a chipboard floor have a look at the ring that has been worn into the board due to thermal movement.

Years ago we used to mount the cylinder halfway up the kitchen wall sitting on a bit angle iron or 1" mi cut into the brickwork across a corner. All the old heads knew the cylinder would fail at the point of contact so would place a bit sheet lead on the bar to help extend the tanks life.

Just not so common sense really.

Btw pet cocks should be banned but thankfully up this way the standard practice for a cylinder drain off is a sludge cock piped to outside.
Click to expand...


Hell Tamz I thought I was going mad thanks for the support and I apologise for everything we ever did to you and you kind in the past, you know Braveheart and all that, can't watch the end of that film ever again, anyway proper support sod the condensation balderdash


Tony
 
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BTW we never asked this chap where the existing cylinder is leaking, hell I hope it's on one of the 3 x 2 I will sleep well tonight if it is...:60: he's probably fitted the new one whilst we are arguing the toss over condensation, BTW I surely can't have failed due to condensation, he's down the pub now laughing at us, how we made it sound so difficult to do.
 
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They don't corrode on the bearers they rub through due to movement through expansion and contaction.
The seam on a grade 3 is a welt of 1.2 and 0.7mm copper brazed at the seam. If you know how a welted joint is made you will know that the thickness of the part to rub through is the 0.7mm.

Yu know me Jon. I can cause an argument in an emtpy shop too :lol:
 
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They don't corrode on the bearers they rub through due to movement through expansion and contaction.
The seam on a grade 3 is a welt of 1.2 and 0.7mm copper brazed at the seam. If you know how a welted joint is made you will know that the thickness of the part to rub through is the 0.7mm.
Click to expand...

That's why i think the stainless steel cylinders are better than copper ones. Thermal expansion of SS is much less than copper. Every joint is welded and warranty for SS cylidners is usually 10 years compared to 2 yrs for copper ones.

Btw copper cylinders are soldered or brazed? For me it's looks like soldered.

( I know, my english is not perfect )
 
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tamz said:
They don't corrode on the bearers they rub through due to movement through expansion and contaction.
The seam on a grade 3 is a welt of 1.2 and 0.7mm copper brazed at the seam. If you know how a welted joint is made you will know that the thickness of the part to rub through is the 0.7mm.

Yu know me Jon. I can cause an argument in an emtpy shop too :lol:
Click to expand...

Is there anything you don't know?
 
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Cylinder sitting on wood bearers has the advantage that you can check condition of copper base & any source of leaks with a torch & a mirror. Timber should be 2" height. If the timber was about 3" wide also & 3 pieces were used, then very little of the cylinder rim will be unsupported (standard cylinder has a 14" diameter base). Proper way to position the timber was to put the outer two slightly outside the rim edge, thus covering a substantial part of the entire rim & also making the cylinder stable.
Can't see there being much difference in thermal movement on all of the base contacting or on just some of it?
The corrosion I see is either due to the stupid aluminium anodes causing corrosion in base, or the water in certain areas.
 
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I wonder if Brian_mk the author of the original post would be kind enough to put the record straight and show us by way of a photo where the sodding cylinder is leaking, perhaps he has taken a look at this thread and thought this lot have not got a clue what they are talking about and he will never darken our doorstep again, if it is leaking on the bottom due to the 3 x 2 and he puts he back on the 3 x 2 he too will have learnt nowt, on the other hand if its leaking from a brazing on a seam or a boss unconnected with the 3 x 2 he will be confident the the 3 x 2 has saved the day with regard to all the good advice dished out on the protection of the base of a cylinder by the onset of condensation, phew!


Tony
 
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