Central heating problem

[aga man]

and often creates one - if you check with the main manufacturers you will find they state dry - some use a little paste but this also causes problems at times as it lubricates and causes the olive not to grip.

 

A few years ago I was involved in a major hospital build where the plumbers/fitters put on ptfe - had to strip out large parts of the install due to leaking compression joints.

seems to be some confusion here. i would not advocate puttting ptfe on new olive/compression joints as there is no need for it as bigben pointed out. for a DIY'er replacing a mid posistion valve at home, they will probably use the existing olives and nuts on the pipework [i have seen this many times in DIY plumbing.] in this instance the ptfe tape around the olive will ensure a better seal.

major leaks on new installs like the hspital you mention is uaually down to bad workmanship/incompetance.

[Yellow Bear]

seems to be some confusion here. i would not advocate putting ptfe on new olive/compression joints as there is no need for it as bigben pointed out. Fair enough for a DIY'er replacing a mid posistion valve at home, they will probably use the existing olives and nuts on the pipework [i have seen this many times in DIY plumbing.] in this instance the ptfe tape around the olive will ensure a better seal. Again I disagree - in this case if we are sure it is heating I would say at worst Boss white or green - DIY'ers tend to overuse ptfe and this would more likely cause a leak than prevent.

major leaks on new installs like the hospital you mention is usually down to bad workmanship/incompetence. In this case the cause was due to an old school plumber who was a foreman insisting that dry was no good and to be fair I had banned paste from the project as it could not be guaranteed that the less competent would not use white on domestic services. A big no no and the local appliance officer was **** hot on checking for it.

[-Mongrel-]

seems to be some confusion here. i would not advocate puttting ptfe on new olive/compression joints as there is no need for it as bigben pointed out. for a DIY'er replacing a mid posistion valve at home, they will probably use the existing olives and nuts on the pipework [i have seen this many times in DIY plumbing.] in this instance the ptfe tape around the olive will ensure a better seal.

major leaks on new installs like the hspital you mention is uaually down to bad workmanship/incompetance.

 

Just to throw a curve ball, I've found that it depends on whether you have brass or copper olives. Brass I use jointing paste as they weep quite often, copper don't. Oh, 26 year time served so not just an opinionated DIY'er either. As for wrapping olives with PTFE, never done it never will, the give away of a DIY job that is, as well as wrapping the threads outside of a compression joint.