Hello, I have a problem that I have controlled but would like some advice over if I may. I have made a few solder fittings on my heating system, but on re-filling 1 of them (a tee) leaked - I have drained system again. The system was dry before I soldered, so I am unsure why it leaked? But now need to un-solder it. I have just tried, I put the blowtorch on the joint for a few minutes but no joy - is there any way to fix this leak? Thank you for offering me any help available.