You basically have to go back to the start with that setup.
Yes get a soldering torch. The trick with soldering on an existing installation is to get the system drained down properly so you can solder the fittings. Pipework with water in it won't get hot enough to allow soldering to take. You may have to blow through/wet vac some of the pipework to ensure it is empty of water.
Old solder fittings will release with heat, again it just needs to be empty of water. Once the fitting is removed have a wet cloth with some flux on it, heat the end and quickly wipe the soldered pipe end, the old solder should lift onto the cloth, just watch your fingers with the heat.
Solder ring fittings are fine to use and easier for a novice to create soldered pipe runs with. Just clean the pipe till shiny, use just enough flux on the pipe end and don't heat the fittings too fiercely (heat the pipe 1st then move flame along to the centre of the fitting) until you see a ring of solder appear at the end, no other solder is required.
The old stop tap can be left if it's too difficult to remove, just extend the copper up a little and pop a full bore lever stop valve in above it after the bend to the left. That allows you to work on the rest at your leisure. The trick there will be making space behind the pipe to use tools as it's currently tight to the wall. Use compression fittings for the new stoptap if you can, pushfit can be a little temperamental on old pipe
Trick with the new pan connector is just make sure it's clean in there and that the rubber fins make a tight fit and it has a fall on it.
Aye thanks Rab
You had a really close look at the pics and really saw my predicament
What you and the other chaps advised is given me a better insight to the constraints
Yer a bonny lad, I'm a Boness man, that's near Linlithgow
Cheers
Geof
