leaking soldered copper joints !

[Dc]

Can anyone advise how to cure a soldered joint on our central heating system which drips once every 10 minutes. I have not fired the boiler up yet and have the pressure at 2.0 bar. I have drained the system down 3 times to fix other leaks but missed this one.( bloody idiot!) Has anyone any ideas how to fix it or know of a product here in France that would do the business. Any help gratly appreciated.

dc

 

[Opel Fruit<P><BR>Opel Fruit, Dept. 53<P>]

The only way to cure it is to resolder it. Which means draining and ensuring the joint is dryer than dry. Which is not usually practical.

Alternatively, cut the offending joint out and use a couple of bicone joints (compression) with a short length of new pipe. Then it doesn't matter if there is a trickle of water.

Not sure why the joint is leaking, (or the others now fixed) but you shouldn't have the cold pressure at 2 bar! It is far too high. Depending on your expansion vessel pre-charge, you should have no more than 1.3 bar cold, all bled.

 

[Nick Trollope]

[quote]Can anyone advise how to cure a soldered joint on our central heating system which drips once every 10 minutes. I have not fired the boiler up yet and have the pressure at 2.0 bar. I have drained the ...[/quote]

Apart from wrapping those 2-part resin sticks around the joint, I would drain down, disassemble the joint & do it again!

Isn't 2 bar rather high for a sealed system? Someone who knows better will probably correct me....

 

[Dave&Olive]

hi

      do not think you will ever reseal this joint even if you drain the system ,without  separting it cleaning it and  re fluxing  it .

the solder will not suck into a hole unless it is clean and fluxed!!

sorry that last line sounds like it come from a shadey movie

pressure on sealed systems ,,, my own view min 1/2 bar cold max 3 bar hot .

                 dave

[Opel Fruit<P><BR>Opel Fruit, Dept. 53<P>]

Sealed system (cold) pressure is wholly dependant on the expansion vessel pre-charge. Anything else is misleading.

0.5 bar is too low for any EV, 3 bar is on the relief limit. If your system is doing this, Dave, you have a major problem! Either your expansion vessel is too small, or it has lost its pre-charge pressure. I strongly suggest you sort it immediately.

If you need any guidance, let me know.

(The topic is covered in the sticky.)

 

[Jonrev]

A piece of rubber and a hose clip will sort it until you have time to fix it properly. Ive seen leaks in high pressure steam valves repaired like that and have lasted for more than six months.

[Dave&Olive]

[quote]Sealed system (cold) pressure is wholly dependant on the expansion vessel pre-charge. Anything else is misleading. 0.5 bar is too low for any EV, 3 bar is on the relief limit. If your system is doing...[/quote]

 

hi

   if you read what i posted i do not have a problem , i just posted the min and max preasure  settings..

     dave

[Opel Fruit<P><BR>Opel Fruit, Dept. 53<P>]

Which are wrong....

the nominal minimum pressure is dependant on the vase d'expansion pre-charge, and is generally 1.2-1.3 bar.

the nominal max pressure with the correct vase d'expansion is 2-2.2 bar at 80C flow temp.

If anyone has pressures outside these figures, they have a problem.

[Dave&Olive]

hi

         just think old french wood/oil burners with no low preasure sensors in the system !!! they will work away quite happy on no  cold preasure in the system as long as they are full off water that is ...

                         dave