Are these words interchangeable? Are they really the same thing? Have I spelled them correctly?
While I'm on the subject: How often do you see 2 installed next to each other, one hot water, one cold? How often do you see foundation guys put platforms with drains underneath them? Do you always mount them on siding blocks, as opposed to just on the siding? What about sillcocks inside the house, or in the garage?
Where I come from, they all mean the same thing.
I once dealt with 3 plumbing supply houses, in the same town - and had to learn 3 different ways of ordering the same fittings! For instance, "male" = "fitting" = "slip". Where I come from we use "plumbers tape;" where I am now, its "hanger iron." Etc. -
I'm not sure where you're coming from on the other questions...
Where I grew up they were always called hose bibs and/or spigots. Out here in Washington state I've heard all three expressions used.
Paul Bianchina's 'Illustrated Dictionary of Building Materials and Techniques' lists spigot and hose bib. No sill ****.
According to Bianchina, a hose bib is a "water faucet with a male thread to receive a female hose connection. A spigot is "the lipped end of a piece of cast iron pipe that fits into the hub end of a similar pipe." (But.."a hose bib, especially one used for washing machine connections.")
Since most of these are located near the sill of the house at the exterior walls, and given the male/female references for hose bib above, I think I know where the term 'sillcock' is derived from. It is probably more a colloquialism than an actual word.
I don't think anyone would have a problem understanding what one meant by hose bib or spigot. But, unless you were in the construction or plumbing trade, sillcock might be a little bit of a mystery to the average joe.
Occasionally, I've seen them inside homes and even garages, but not always mounted on blocks. In fact, most of the time they just protrude out of a hole cut through the siding. I've never seen an arrangement with two as you've described.
I would imagine that a hose bib carrying hot waterwould be a safety issue since it would not be mixed with cold, just water at watever the water heater is set at. I guess a removable handle would help keep anyone from getting scalded by mistake. My father suggested that I install one when I was putting in my water heater. He thought it would be good for washing cars. I wondered if it would be a code violation.
I too have wondered about the hot water hose bib code issues. I've only seen it installed twice. Once for washing cars, and once for a back deck location where the owner wanted it for parties. I don't really know what it was for exactly. Maybe it had something to do with cooking on the grille out there. I had not thought about the water temp and lack of mixing, the installations were twin hose bibs, about 6 inches apart. I think the guy got the idea from his office water cooler, which has the optional hot tap for tea/coffee etc. I wonder if there is a hot/cold exterior hose bib with mixing valve?
Another neat thing I saw a while back was a special setup for the garden hose. The foundation contractor installed a special concrete pad that was sloped like a shower base & connected to the leader drainpipe. The hose was all arranged nicely on the wall off to the side. A great place to hose off those muddy kids before they come inside.
A better idea for hot and cold water at a hose bibb location----My plumber will install a shower valve either above or beside a regular hose bibb to allow you to mix the water temp rather than having either your hose hooked up to cold only or hot only. Works great and the customers love the idea.
Several manufacturers make frost proof hot/cold 'hose bibbs' units. There is one that has a temperature control that you can adjust. Others just have two knobs and one outlet. Of course, anti-siphon is important.