replacing old compression fittings with combi install

[JohnD]

Tue Oct 16, 2007

 

[spacethegas]

You are going to have much higher pressure hot water than before with the new boiler(assuming old boiler was a conventional one) and may get small leaks from old/not well done joints and from taps to start with (especially on the domestic hot water supply side). Best thing to do if you are not going to renew old pipe work and old rads is to redo the joints that fail and fix leaking hot taps, assuming not all and only a few fail (small leaks i.e. drips not proper) - should be quite easy. I am an expert at this as i have recently had a new combi boiler and re-did all the pipe work in my maisonette in chrome pipe after using the old boiler to beat Fernox round the system for a month prior to installing the new one. There's loads of lovely chrome pipe on show as the floor is concrete! So new combis is in loft and all pipe work comes through ceiling to rads.

What about the old system?- your "plumber" will need to do some pipe work to install the boiler and run the new cold in feed and domestic hot water supply. Central heating pipe work shouldnot change too much if new boiler is going in same place as old one. Presumably you are going to have to lose the old hot water tank?

Not all Corgi guys are any good at plumbing. For defs!

i cant possibly visualise all these chrome pipe runs & imagine them looking "lovely".
can you show us some pics ?
what sort of fittings did you utilise ?
how did you get on with it in the benders ?

 

[heatingman]

Always reminds me of public toilets, sorry.

 

[Bahco]

Theres no flies on you Mr perfectionist!

 

[Perfect1onist]

Ah ha, are there any public loos left? Naw up market hotel or something? Come on! The photos are to follow-when i figure out how to do it-can be arsed.

Bending 15/22mm chromed copper pipe is no probs as long as the pipe is standard the normal pipe bending kit is what i use, just a small dab of WD40 on the former (the bit that glides against the pipe) and take it slow when using them to bend 90 degree angles. The compression fitttings, from screwfix, although ballofix are good (available from Plumbcentre).
I pre assemble as much as i can so i can get a good crunch on them but not too far, just far enough so the olive is just showing all the way round the inside of the nut snug around and against the pipe.

Then de assemble and apply a little ptfe tape along the olive and around the thread, re-assemble in place and good tighten back up. Apply the water pressure and check for leaks. Small amounts of little drips are acceptable as long as they go away after a week or so. Place some old newspaper underneath and check for big drips.

If there are small drips dont worry beacuse in time (after a day or two) the copper olive starts to oxidise as it comes into prolonged contact with the water along with the ptfe the joint gunges up inside and the seal is made for good. If not a small amount of tightening will usually cure small drips. Not too tight though (dont know my own strength some times) cracked a nut on the mixer shower feed once.

Nightmare - had to cut the pipe and re-do! Nothing-nothing leaks now and wont either!

 

[spacethegas]

i'm gonna learn so much.
cant wait for pics.

 

[spacethegas]

by the way i think you mean the 'guide' not the 'former'.

hang on you might be right.

which bit glides ?

leaking chrome compression ooooo lovely.