Reinstalling radiators

[meddyliol]

We have had some radiators removed by a plumber to enable plastering etc. One of the pipes was capped off by a soldered joint. I find that I cannot get a plumber for love nor money so will have to do it myself. Firstly, what is the procedure for removing the soldered cap (I know I have to unsolder it and I do have a small blow torch. If I have to drain the system how do I do it, it's a combi boiler). I can put the radiators back on with no problem!! but the issue is the soldered cap.
Sorry for asking a dumb question, it's probably obvious to most but not me.

Thanks

Brian

 

[AC Power]

Well, you most definitely have to drain the system of some of it's water, at least the water at/around the end cap. The WHOLE system needn't be emptied. And yes, a small torch will likely produce enough heat to remove the cap. Heat the cap up, and use a pair of "water pump" pliers (AKA channel lock pliers, adjustable plyers) to rotate the cap CW, then CCW, CW, then CCW. Keep doing this with the flame applied until the cap comes off.

However, do you know how to re-solder (AKA sweat) copper lines/fittings?

 

[meddyliol]

Thanks for that. Yes, I am OK with soldering.

 

[piglet11]

Capping the pipe off with a soldered stop end/end stop was not the greatest choice especially as it was a temporary measure.
A much simpler solution would have been to fit a push fit stopend like those from John Guest Speedfit.
All it needed was a clean smooth end to the pipe, no sharp bits of presumably copper and just push the fitting on as far as it will go.
Removal is simple and you don't have to clean the pipe up from the previous solder cap.
Worth having some of the fittings for any pipe leak/seal jobs.

As for draining systems, often not necessary.
Just use a pipe freezing kit to plug the pipe before the repair, have your tools etc. ready to hand and you will have about 30-minutes to do the job.
15-mm copper is easy, larger sizes need longer to freeze.

Convenient, doesn't need replacement of stuff like Fernox or repairs to drain cocks that start leaking because they haven't been used for years.

 

[AC Power]

Hands down soldering is the best option. Any compression fitting claiming to seal upon an "uncleaned" pipe is very questionable. Turning the water off to a hot water loop is VERY easy....there is no need for a pipe freeze. Using a pipe freeze for this???....come on.