Shut off the water at the house valve, drain the line, then match the new faucet to the old one: same inlet type (threaded, sweat or PEX), same length, and an anti-siphon model. Mount it with the spout pointing down and a slight downward pitch so it drains. Restore pressure slowly and check for drips.
What to check before you buy the new faucet
Pull the old faucet's details first. Three things must match.
The inlet connection. This is how the faucet joins the pipe inside the wall. Manufacturers sell the same hydrant with different inlets. Arrowhead Brass lists its 490 series with these choices: 1/2 inch copper sweat, 1/2 inch female pipe thread, and 1/2 inch or 3/4 inch PEX (crimp or cold expansion). Look at the pipe behind the wall, from a crawlspace, garage or the back of the wall, before you shop. Copper in a sweat cup needs a torch. Threaded needs two wrenches. PEX needs the right ring or clamp tool.
The length. A frost-free faucet has a long tube that puts the shutoff seat inside the warm part of the wall. Arrowhead's 490 series, for example, comes in lengths from 4 to 14 inches. Measure the wall thickness, including siding, and pick a tube long enough that the valve seat sits inside the house envelope. Our page on how a frost-free hose faucet works explains why.
Anti-siphon protection. Woodford's Model 17 and Arrowhead's 490 series build the vacuum breaker into the faucet, rated to ASSE 1019. That keeps hose water from being drawn back into your drinking water. If your old bib had a screw-on cap, read how a hose bib vacuum breaker works. Arrowhead also notes its 490 series is made of lead free brass and copper, certified to NSF/ANSI 372.
Do you need a permit?
For a like-for-like swap, no. The City of Phoenix lists "Plumbing - replacing existing fixtures and existing landscape irrigation" among the home projects that do not require a permit. Permits are required to move or add sinks, toilets and tubs. A new hose bib in a new spot, with new pipe run to it, is a different job, so check with your city before you cut into walls. Other Valley cities set their own rules, and their building departments can confirm theirs.
Step-by-step: swapping the faucet
- 1Shut off the water. For most houses, Phoenix Water Services says the house valve "is usually located at the front of the home, near a hose bib." Close that valve, not the one at the meter. The city's advice is plain: "It's important for you to NOT shut your water off at the meter."
- 2Drain the line. Open a faucet at the lowest point in the house and open the outdoor bib you are replacing. Remove any hose.
- 3Disconnect the old faucet. For a threaded inlet, hold the inside fitting with one wrench while you turn the faucet with the other, so you do not twist the pipe. For sweat copper, it is often cleaner to cut back and rebuild the joint than to fight an old one. For PEX, cut off the ring and slide the tubing off the barb.
- 4Prep the wall. Woodford's instructions call for a 1-1/8 inch hole through the wall, with the faucet inserted from the outside. If your old hole is already that size, you are set. Flush the supply line before connecting. Woodford says: "Before installation, flush supply line to remove any debris." A pebble of scale under a new seat is how a brand-new faucet starts dripping.
- 5Mount it pointing down. This is the step people miss. Woodford's rule is "Install with nozzle pointing down," and "The tube must have a slight downward pitch for proper drainage." Use the alignment mark on the tube as your guide, and secure the flange to the wall with fasteners. The flange adjusts to match siding slope on Woodford's model.
- 6Make the connection. If you solder, Woodford says to open the faucet fully first, "For solder connection, open faucet to full open position before soldering," because "Excessive heat can damage valve seat rubber or stainless steel seat and factory solder joint." Keep a heat shield between the flame and the wall.
- 7Restore water slowly. Open the house valve a quarter turn at a time, check the inside joint with a dry paper towel, then open the faucet and watch the spout. If a drip shows at the handle, the packing nut can be snugged. Woodford notes that it "can be tightened to stop the leak."
Phoenix details that change the choice
Phoenix does not freeze like Flagstaff, but it does freeze, and Phoenix Water Services still advises residents to remove, drain and store hoses before a freeze warning. A faucet that cannot drain is the weak point. Woodford puts it directly: "Improperly installed or operated wall faucets may freeze and burst in freezing weather." In the desert, sun is the other wear factor: rubber washers and plastic parts on a sunny wall tend to wear out sooner than the brass body.
Do not leave a hose on the faucet under pressure for days. Woodford notes its ASSE 1019 device "shall not be subjected to more than (12) hours of continuous water pressure." That matters for drip irrigation tied directly to a bib. If your sprinkler or drip line stays pressurized, put a valve and the right backflow assembly between the faucet and the irrigation instead, as covered in backflow preventers for sprinklers in Arizona.
If you want winter-ready habits after the swap, follow how to winterize a hose spigot in Arizona.
When to repair instead, and when to call a licensed plumber
Not every leaking bib needs a new faucet. A drip at the spout or handle is often a washer or packing problem, covered in why an outdoor faucet or hose bib leaks. Replace the whole faucet when the stem is frost-split, the body is cracked, or it has no anti-siphon protection.
Bring in a licensed plumber when the pipe behind the wall is corroded galvanized steel that will not release, when you cannot reach the inside of the wall, when the shutoff valve itself will not close (how to test your main water shutoff), or when you find a wet wall after a freeze. HQ Plumbing and Air handles hose bib replacement as part of residential plumbing service, with an upfront price before work starts.