Winterize Outdoor Faucets, Hoses, and Irrigation Before a Washington Freeze
The work is to get the water out of everything that holds it, and the step that decides whether the rest of it works is the hose. Disconnect it, drain it, and store it. A faucet with a hose still threaded on cannot drain, whatever the faucet’s own design does, and the water left standing in the tube through a freeze is what cracks it inside the wall.
The date that governs the job comes from the forecast rather than the calendar. Washington’s first freeze runs from the beginning of September in the mountains to the last weeks of October in the river valleys, and the National Weather Service issues frost and freeze watches and warnings for the week that matters. One item on the list is usually someone else’s work, and it is the one with compressed air in it.
Why a hose decides the outcome
A frost-proof faucet — sold as a freezeless wall faucet, sillcock or hydrant — moves the valve indoors. The valve sits in the heated part of the wall, a tube crosses the wall to the outlet, and when the handle closes, the water left in that tube drains out through the nozzle. Woodford’s installation instructions for its Model 14 and 17 wall faucets state the two conditions: “The tube must have a slight downward pitch for proper drainage,” and “Water Supply Connection Must Be Installed in a Heated Space.” PRIER’s instructions for its 400 Series hydrant repeat both — the valve “must be installed into a heated area of the structure that will not drop below freezing,” and “all freezeless wall hydrants require a slight downward pitch to aid the draining process.”
Anything that seals the outlet defeats that drain. Arrowhead Brass’s guide to its frost-proof wall hydrants traces what follows: with “a hose or other device … left attached to the faucet (such as an irrigation timer, ‘y’ hose splitter, or add-on back-flow preventer), water will remain trapped inside the wall hydrant”; the water in the hose freezes first, the ice moves back toward the seat, “and the pressure inside the copper tubing will exceed capacity and burst.” The maker’s summary is a rule: “Properly installed valves (with downward tilt) will always drain unless a hose or other device was left attached.”
The warning is printed on the product: Arrowhead’s gap spacer wedge is labelled “REMOVE HOSE IN FREEZING WEATHER,” and Woodford’s catalogue warning reads, “Faucet must be installed with downward pitch toward nozzle and hose must be removed in freezing weather or faucet may freeze and burst.” Woodford’s technical note on its yard hydrant names the failure as the only one there is: “the only possible cause of the bursting of the hydrant head or tube is an obstruction such as a hose being left on in freezing conditions or the improper installation of the product that prevents the water from draining.”
What has to come off
Anything threaded onto the outlet is the obstruction the makers describe.
- The hose. Washington Water Service’s instruction is to “remove, drain, and carefully store hoses used outdoors.”
- Splitters and timers. The same maker that names them states that its wall hydrants are “not designed for constant pressure applications (i.e. sprinkler & drip timers, ‘Y’ Shut-offs).”
- A self-closing nozzle. Arrowhead’s instruction is to “always relieve pressure after shut-off.”
- The faucet itself, once the handle is closed. PRIER states that the hydrant “will drain for a few moments,” and that if dripping persists after that, the handle needs a slight turn. Arrowhead gives the duration as “approximately 15-20 seconds” of steady, gentle flow. A faucet emptying itself is not leaking.
Which faucet you have, and what it needs
Two checks can be made from the ground. The first is the angle: the spout should sit slightly lower than the point where the body enters the wall. Arrowhead states that a hydrant installed level or at an upward angle “will not drain properly and may lead to freeze damage,” and Woodford and PRIER both require the downward pitch for the same reason.
The second is which kind of faucet it is. The Institute for Business & Home Safety’s winter checklist states that if you do not have frost-proof outdoor faucets — “homes built before 2010 typically do not” — the alternatives are to “turn off the valve for outdoor faucets inside your home or cover them from the outside.” Washington Water Service names the cover — “purchase insulation covers and cover all outside faucets” — and the City of Bellevue’s water utility states the drain half: “Disconnect outside hoses and drain any water remaining in the hose and hose bib.”
Irrigation: shut off the supply, drain the lines, and know who empties them
The Environmental Protection Agency states the deadline in one sentence: “Winterize your irrigation system by shutting off the water supply and draining the lines before freezing weather arrives.”
What gravity cannot empty is where the damage happens. Hunter Industries, an irrigation manufacturer, states the consequence for its own components: water that remains in a system “can freeze, expand, and crack PVC piping”; polyethylene pipe is more flexible, but “water left inside can freeze and rupture the pipe walls”; and “freezing water in the backflow assembly will damage the internal components and can crack the brass body.”
The maker’s instruction on the compressed-air method — the blowout — opens with a caution rather than a procedure: “Due to the potential dangers involved with winterization, it is best to call a professional,” and on the method itself, “It is best for a qualified licensed contractor to perform this type of winterization method.” Two of its limits matter when quotes are compared: the same document sets the ceiling at 50 psi for polyethylene pipe and 80 psi for PVC pipe, and states that compressed air “should not be blown through any backflow device” — the compressor connects downstream of it.
Antifreeze is not a substitute unless a system’s own instructions call for it. Washington Water Service’s instruction is to drain pool and sprinkler lines “following the manufacturer’s or installer’s directions. Do not put antifreeze in these lines unless directed,” because antifreeze “is environmentally harmful and is dangerous to humans, pets, wildlife, and landscaping.”
The drain and the annual test are two different appointments
Washington’s plumbing code requires potable water supplies to lawn sprinkler and irrigation systems to be protected from backflow, and lists the accepted methods: an atmospheric vacuum breaker, a pressure vacuum breaker assembly, a spill-resistant pressure vacuum breaker, a reduced pressure principle assembly, or — where the water purveyor and the authority having jurisdiction allow it — a double check valve assembly. It also requires a testable assembly to be tested by a Washington Department of Health certified backflow assembly tester at installation, repair or relocation “and at least on an annual schedule thereafter,” unless the local authority requires more frequent testing.
The Department of Health’s cross-connection rule supplies the distinction that matters in the fall. Where the protection sits at the point of hazard, “the purveyor may accept an approved AVB on a residential irrigation system, if the AVB is properly installed under the UPC”; an AVB on an irrigation system is inspected at installation, after a backflow incident, and after repair, reinstallation or relocation — not on the annual test schedule that applies to an assembly. The department keeps the list of approved assemblies and certifies the testers who work on them.
Two consequences follow. An air blowout is not a test: air through the pipes in October does not satisfy an annual test, and the equipment maker’s instruction is that air should not pass through the backflow device at all. And a test is not household work: the code names a certified tester for it. Which assembly your system carries, and what your water supplier expects of it, is a question for the purveyor, whose requirements can be more frequent than the state’s minimum.
When the water is due to freeze
The National Centers for Environmental Information defines the median first-freeze date as the date by which a freeze has happened in five years out of ten, and notes that elevation, latitude, topography and development all move it. Its regional summary puts the Northwest’s window between the beginning of September and November, and it cautions that its maps are “a generalization and not absolute.” The watches and warnings the National Weather Service issues for an area are the forecast to plan around.
One forecast office’s long-term averages show how wide that window is inside a single region: Republic, September 7; Colville, September 19; Leavenworth, September 27; Pullman, October 1; Spokane, October 7; Wenatchee and Lewiston, October 21. The same newsletter draws the line that decides whether the work is late: “A frost forms with a short duration temps to 32°. A freeze forms with a long duration of temps to 28°.” A light frost is the warning; the hard freeze is the deadline.
What belongs to someone else
- The blowout. The equipment maker recommends a qualified licensed contractor for a method whose risks have nothing to do with water.
- Anything electrical. Two Washington water utilities name electrical heat tape for pipes that freeze even when insulated; the product’s maker publishes the installation instruction, and this publication does not treat a warmed pipe as a drained one.
- A frozen line you cannot see. The Institute’s checklist is explicit: if water is not flowing, the pipes may be frozen — “shut off the water supply and call a plumber to make repairs.” The maintenance calendar carries that stopping point.
- The backflow assembly. Testing it and opening it up belong to a certified tester.
The next useful action
Work from the forecast. Disconnect and drain every hose and every device on the threads. Close the faucet and let it empty. Look at the angle from the side once: if the spout is not the low end of the run, put a plumber on the list before winter rather than after. Shut off the irrigation supply and drain it, then book the blowout and the backflow test with whoever is qualified for each. Write down the date of the first freeze you see; the fall checklist keeps the rest of the season in order, and the maintenance calendar keeps all four seasons in sequence.
Then run the faucet for the first time after a hard freeze while someone watches the wall, the basement or the crawlspace behind it. A burst tube leaks inside the wall, and a leak shows itself when the water is on.