Connections to a copper hot water cylinder

[Skyedriver]

About to install a copper cylinder, the connections have no olives or seals, is PTFE tape ok for this? Ditto the immersion heater. Had trouble once before with the copper cracking around the immersion boss on an old tank.
Forgot to get a drain for the bottom.....back to Jewsons......

Oh and how many times around the thread with the PTFE tape please?
Cheers

Edited by Skyedriver on Friday 30th July 23:48

[dirkgently]

Skyedriver said:

About to install a copper cylinder,

Edited by Skyedriver on Friday 30th July 23:48

Are you sure you want to do this? Check you insurance is up to date ;-)

[caziques]

Really, really wouldn't suggest PTFE tape - hemp is far superior.

[Mr GrimNasty]

I used a jointing compound/mastic on the course thread of the couplers that screw on to the pipe connectors and have compression fittings on the other end.

The fibre or neoprene washer should seal the immersion OK, but a few wraps of PTFE tape anti-clockwise will be belts and braces and aid future removal. Careful not to cross thread. Do it up hand tight, then a couple of solid taps on the 'spanner' with a hammer - without twisting the tank into a spiral!

[eldar]

Check the connections are all the same size. Some cyls have imperial connectors. My new cyl had a 3/4" outlet.

[Gingerbread Man]

Immersion heater wise, go buy some LSX silicone sealant (jointing compound). Comes in a small tube like toothpaste, yellow and blue box.

Put some of this on the fibre washer and tighten up the immersion with an immersion spanner. PTFE is not needed.


Cylinder wise, you coan buy cylinder unions that go to 22mm compression. Probably your best bet. PTFE round the threaded section ~22 (ish) times and screw tight into the cylinder. You could use jointing compound on these as well if you like - liquid PTFE/ LSX would do if you had some but it should be fine with just PTFE.

Edited by Gingerbread Man on Saturday 31st July 14:26

[Mr GrimNasty]

Ask 10 different people you'll get 10 different answers.

IMO LSX is not necessary as the thread does not make the seal, the gasket does. And although LSX does not set rock solid, it will make it harder to disassemble in the future. But ptfe is also a dry lubricant and will help.

[Gingerbread Man]

Mr GrimNasty said:

Ask 10 different people you'll get 10 different answers.

IMO LSX is not necessary as the thread does not make the seal, the gasket does. And although LSX does not set rock solid, it will make it harder to disassemble in the future. But ptfe is also a dry lubricant and will help.

I said to put it on the gasket, not on the threads. It's just belts and braces, worth doing.
LSX won't make it hard to dismantle in future, I undo joints with jointing compounds on daily and never really had issuses.

[Ferg]

1" male iron fittings to 22 or 28mm copper compression for the cold feed and vent connections sealed with PTFE tape (about 30 wraps). Try to get cone-seat cylinder unions for the heating coil and put a smear of jointing paste on them. I'd put a smear on both sides of the immersion heater washer too, but make sure you don't get any in the thread.

[Skyedriver]

Thanks everyone.
Not using the heating coil, just the cold in, hot out (vented) and the immersion. Of course my immersion spanner is 350 miles away....and today I fitted a new toilet, needed a socket to tighten the holding down brackets to the floor. Came in with the sockets on a bar, and one dropped off. Hole in one and away down the drain, Tiger Woods eat your heart out.

[Gingerbread Man]

Skyedriver said:

Thanks everyone.
Not using the heating coil, just the cold in, hot out (vented) and the immersion. Of course my immersion spanner is 350 miles away....and today I fitted a new toilet, needed a socket to tighten the holding down brackets to the floor. Came in with the sockets on a bar, and one dropped off. Hole in one and away down the drain, Tiger Woods eat your heart out.

Toilets are always a bain of life!

[Smiler.]

Can someone in the know advise on these connections:







The 1st pic shows a valved draw-off for a pumped shower (15mm).

The 2nd pic shows the main hot feed from the HWC & vent (22mm).

The 3rd pic shows the connections for the hot water heating coil.


I need to take the tank out to make some repairs to the airing cupboard & I'd like to re-use it.

My questions are:

1.
Will I (or a plumber) be able to remove & replace the output hot water pipework & be able to get a satisfactory seal? I intend to drop 22mm barrier pipe from the roof space & make a coupling to copper. Can flexible connections be used?

2.
Does the 15mm connection to the pumped shower need a valve at the tank? The existing one is buggered (doesn't fully close) so I've fitted the level ball valve seen in pic 2.

3.
Same question as 1. for the connections for the hot water heating coil connections (pic 3).

Thanks in advance.

[Ferg]

God knows what's going on with that draw off connection!!!

One valve is good enough for the hot to the shower.

I never valve heating pipes, but it's up to you.

[Ricky_M]

Agree with Ferg. I've always used PTFE when dressing a cylinder and never had any problems. Immersions I fit with just the Gasket, never used jointing compound.

I dislike using LSX unless it is an emergency, infact I don't even think I carry it on the van anymore.

PTFE is cheap, just keep trying until you think it is right. I'm always taking fittings back out to re-apply with a few more wraps!

[Smiler.]

Thanks Ferg.

Do you chaps think I can replace the connections in/out of the HWC?

What about flexibles?

[Ferg]

Smiler. said:

Thanks Ferg.

Do you chaps think I can replace the connections in/out of the HWC?

What about flexibles?

I would steer clear of flexible connectors wherever possible. Very few are rated at the sort of temperatures in a heating system anyway. A lot are only rated at 65!!

[Smiler.]

Cheers Ferg, I have since found out that they are only suitable for hot & cold water, & the bore restriction on a 22mm is dreadful.

Anyway, I now need a new cylinder, is this any good?

http://www.screwfix.com/prods/40082/Plumbing/Hot-W...

[Ferg]

Smiler. said:

Cheers Ferg, I have since found out that they are only suitable for hot & cold water, & the bore restriction on a 22mm is dreadful.

Anyway, I now need a new cylinder, is this any good?

http://www.screwfix.com/prods/40082/Plumbing/Hot-W...

Fine.

[Smiler.]

Ferg said:

Smiler. said:

Cheers Ferg, I have since found out that they are only suitable for hot & cold water, & the bore restriction on a 22mm is dreadful.

Anyway, I now need a new cylinder, is this any good?

http://www.screwfix.com/prods/40082/Plumbing/Hot-W...

Fine.

Ta

[Smiler.]

Job done.

I only used PTFE (Plumbers Tape for Everything) for the tank connections & the immersion (with the gasket).

The top connection was not sufficiently plied with tape, so a quick re-app seald it.

Thanks for all the assistance chaps