How to winterize a pressure washer before the pump freezes.

This is the storage pass after a season of washing. The job sequences stay where they are: the driveway how-to, the house how-to, and the foam and soap guide for what was allowed in the system. Flush the cannon with clean water before you put the machine away. Bleach never went through the inlet. It does not go in for storage either. If you are taking the gun and wand apart, the quick-connect wand guide is the fitting check.

Gas and electric are not the same job

The pump is the shared problem. The engine is not. Read the book that came with the machine before you borrow a step from a different brand. These are the splits the manufacturers actually publish.

• Gas. Fuel stabilizer in fresh gas, engine run with water flowing, then shut down. Drain the hoses, gun, and wand. Pump saver with the engine switch off. Store it where gasoline fumes are not sitting next to a flame.
• Electric. No fuel, no oil, no stabilizer. Unplug it. Relieve pressure, disconnect, and drain. Pump saver still applies if the inlet fitting matches the bottle. Store it indoors, above freezing, off the furnace.

Fuel, then oil, on a gas engine

Simpson’s winterizing page and Briggs & Stratton’s storage article both treat the fuel before they touch the pump, and both want fresh gasoline plus stabilizer rather than a tank you ran dry. Simpson says a full tank of treated gas is easier on the fuel system than storing it empty. The STA-BIL Storage listing’s own directions are the dose: 1 oz per 2.5 gallons of fresh fuel, tank about 95% full so condensation has less room, then run the engine for 5 minutes so the treated gas reaches the whole fuel system. The listing says that keeps gasoline fresh for up to 24 months, including ethanol blends.

Keep water moving while that engine runs. Simpson’s winterizing page says a few minutes with the water on and the trigger pulled — a nozzle is not required. Their short-term storage FAQ says ten minutes, squeezing the trigger often enough that water keeps circulating and the pump does not overheat. Briggs says about two minutes to circulate stabilizer. Use the longer of the bottle and your engine manual. Do not do this pass with the garden hose off.

Oil is the engine manual’s step. Simpson’s storage FAQ tells you to consult that manual for long-term engine storage. If it calls for an oil change before the machine sits, use the viscosity and the interval printed there. This page does not guess them.

Drain the hose, the gun, and the wand

Shut the engine off and let it cool. On an electric, unplug it. Shut off the water. Point the gun in a safe direction, squeeze the trigger to dump trapped pressure, and set the trigger lock. Briggs and Simpson both want that relief before the hoses come off.

• Disconnect the garden hose from the pump and from the spigot. Drain it before you coil it.
• Disconnect the gun from the high-pressure hose. Simpson says to hold the gun vertical and squeeze the trigger so stored water leaves, then put the gun back on its holder.
• Disconnect the high-pressure hose from the pump and drain it. Simpson says compressed air if a puddle stays in the hose. Kärcher’s electric manuals add one storage rule: do not leave that hose kinked.
• The wand comes off with the gun. Tip it so water actually leaves. A quick-connect that still has water in it will freeze the same as the pump.

Briggs’ storage article then says to pull the recoil about six times to empty the pump of liquid, and only after that to add pump saver. That pull-dry step is theirs. If your manual does not say it, do not sit there yanking a dry pump.

Kärcher’s electric manuals (the K 2, K 3, and K 2500 E family) are a different, shorter purge: disconnect all water connections, turn the machine on for a few seconds until the water that was left in the pump exits, and turn it off immediately. That line is written for those electrics. It is not a gas-engine step. If your manual does not say it, skip it.

Pump saver, with the machine unable to start

Pump saver is antifreeze plus lubricant, made for the pump. Kärcher’s Pump Guard page says ordinary antifreeze is not enough and is not what they recommend. The Briggs & Stratton 6039 listing is a 4 oz antifreeze-and-lubricant formula for pistons and seals, for most brands, before storage and again before next season’s startup. That listing does not publish a freeze-point number. Follow the bottle.

The machine stays off the whole time. Simpson’s winterizing page: engine switch off, attach the pump guard at the garden-hose inlet, inject until the fluid leaves the high-pressure outlet — about 30 seconds — and catch the splatter with a rag. Their FAQ says press until water and pump guard both come out of the high-pressure port, then detach it. Kärcher’s gas manual (Pump Guard 9.558-998.0) says screw the bottle into the water inlet, squeeze, put the stop switch in STOP, and pull the starter until fluid starts to exit. Briggs’ storage article uses a short garden hose, about a yard, on the inlet, with eye protection and a tarp, then two pulls of the recoil. If your pump has a drain plug instead, the manual’s picture wins. Do not invent a third path.

The 6039 listing says to use it before storage and again before startup next season. In the spring, follow the bottle, connect the water, and purge the way the manual says before you point the gun at the house.

Where it sits, and what a cover does

• Gas. Simpson’s winterizing article: a dry, ventilated place with no source of flame — not the furnace, not the water heater. A fueled engine does not belong in a closed basement.
• Electric. Simpson says an electric is the machine that can sit in a warm indoor space such as a basement. Kärcher’s electric manuals are pickier about the room: it must not reach freezing, and it must not sit next to a furnace or other heat that can dry the pump seals.
• Outdoors. Simpson’s manual tells you to store the washer indoors so leftover water cannot freeze, or to use pump guard if it has to sit outside. Pump saver is the freeze protection. A cover is not.
• Cover. The WEN PW31C listing is a weatherproof cover designed for the WEN PW31. It also says the cover fits a machine up to 23 × 20.5 × 39 inches (L × W × H), with a vinyl exterior, a cotton lining, an elastic base, and a drawstring. Measure yours. The manufacturer copy calls the vinyl water-resistant; the feature list also says waterproof. Either way, put it on after the pump is protected.

Picks that match this job

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