Just to expand on HJ's comment about saddle valves. As he says, no pro would install or recommend a saddle valve, but they are often used by homeowners and/or hacks for a quick and easy way to add a supply for ice makers, and humidifiers. What should be used is a tee in the main water supply line and fittings to adapt to a copper line going to the appliance. There actually are a couple of other ways this can be done satisfactorily as well. Main thing is to avoid saddle valves. Yes, a bit more work is involved and a little expense, but worth it.