It was warm enough today to shut off the boiler and replace the reduction valve and relief valve. Drained the whole system and heated up the copper pipe to pull an elbow apart so I could get the valves out. Got it all back together and refilled the system to find two leaking joints. Neither of them were mine. My five joints were water tight. It was the factory joints that I assumed would be fine. Oops. Drain it all again and do it over.