Is that not supposed to be an outside hose spigot?I followd the copper pipe, and it merges with a pipe that comes out of the boiler, but not from the normal hot water ends.wondering if its not supposd to be an outdoor spigot
Without being able to see it and run some tests this answer is an educated guess! I suspect that your tracing of the pipe back to the boiler conclusion that it's NOT from the normal hot water outlet pipe indicates that it is tapped into the cold water inlet supply pipe TO the boiler. IF that is the case, I also suspect that the spigot is just an outside cold water supply for which whoever installed it did NOT have a normal exterior spigot, and used that yellow handled valve [which by the way is probably a Ball valve which is much better than the ordinary faucet]. Test by opening the valve for a couple of minutes to confirm water flow, and determine IF it's cold water, or hot. IF cold I still stand by my above suspicions.
