Fix water leak on copper tubing for radiator. What would have been a much quicker repair took longer because the section of radiator would not drain. I found a short piece of 3/4 copper and 2 couplings and cut into the leaking pipe to force it to drain. Once the water was out of the pipe, the repair was achieved. I turned the water back on and the boiler. Radiators are heating and there are no leaks. It’s an oil burning boiler but customer had no issues with it and was aware that I could not service it.