How to Store a Pressure Washer for Winter

This is the least interesting page on the site and possibly the one that saves the most money. Pressure washers rarely fail from use. They fail from being put in a shed in October with water still inside them.

The mechanism is simple physics. Water expands as it freezes. Water trapped in a sealed pump housing has nowhere to expand into, so it pushes against the housing and the internal seals until something gives. The pump is the most expensive component in the machine, and on a budget unit replacing it costs more than the washer is worth.

The cruel part is the delay. Nothing dramatic happens in January. You find out in April, when the machine runs but will not build pressure, and by then the receipt is long gone.

Draining the hoses is not enough

This is the misunderstanding that catches most people out, and it is worth stating directly: water remains inside the pump housing after the hoses are drained. You cannot see it, you cannot tip it out, and it is exactly where freezing does the expensive damage.

That is why a proper winterizing procedure has a step involving pump saver or antifreeze. It is not belt-and-braces. It is the step that actually addresses the problem, and everything else is preparation for it.

The procedure

Manufacturer guidance puts the whole thing at around fifteen to twenty minutes. Do it on a mild day rather than the first frosty one, and check your own machine’s manual as well — the outline below is general.

1. Shut down and depressurize. Switch off, disconnect from the power supply and turn off the water. Then squeeze the trigger on the spray gun to release the pressure still held in the hose and wand. Do this before disconnecting anything.
2. Disconnect and drain the hoses and gun.Remove the high-pressure hose, the garden hose and the gun. Hold each one vertically and let the water run out, then coil them loosely — tight coils over months set kinks into a hose that never fully come out.
3. Flush the pump briefly. With no hose attached, run the machine for a second or two to push out water still sitting in the pump. Keep it very brief: the pump depends on water for lubrication and running dry for any length of time damages it.
4. Add pump saver or RV antifreeze.The step that matters. Connect the bottle to the pump inlet and squeeze until you see product emerge from the outlet — that is the confirmation that it has displaced the residual water all the way through. Use a proper pump saver or RV-type antifreeze; do not substitute automotive antifreeze unless your manufacturer specifically permits it, as many pumps are not designed for it.
5. Empty and flush the detergent tank. Soap left standing all winter separates and thickens, and a blocked siphon is an annoying spring problem. Rinse it through with clean water and leave it to dry.
6. Clean the inlet filter and the nozzles.Pull the water inlet screen and rinse it. Clear the nozzle tips with the cleaning pin. Debris left in place dries hard over a few months and restricts flow next season — and low flow is exactly what ruins foam cannon performance.
7. Check the cord and the hose. A good moment to look for nicks in the power cable and bulges or splits in the high-pressure hose. Finding a damaged hose now beats finding it under pressure in spring.

Where to put it

Dry, well ventilated, and off the bare concrete. Concrete floors run cold and draw heat out of anything sitting on them, so raise the machine onto wood, a pallet or a shelf. Cover it to keep dust out.

A properly winterized machine is fine in an unheated garage or shed. A machine that still has water in the pump is not fine anywhere that drops below freezing, and no amount of covering changes that.

Store the accessories with it rather than scattered: the cannon, the nozzles, the adapter you had to order separately. Rinse your foam cannonthrough with clean water before it goes away — dried soap in the mesh is one of the most common reasons a cannon that used to foam properly does not in spring.

If you wash through the winter

Plenty of people should — road salt is corrosive and getting it off the car matters, which the winter washing guide covers. In that case the machine is in use rather than in storage, and you want a shortened version after every wash:

• Depressurize with the trigger.
• Disconnect and drain the hoses and gun.
• Bring the machine somewhere above freezing — indoors, a heated garage, a utility room.

Manufacturer guidance is to run the full procedure whenever the washer will be stored for more than about thirty days. So if you wash monthly through winter, the short routine is enough. If you get to the end of November and realize you have not touched it since October, do the full thing.

Bringing it back in spring

Straightforward. Connect the garden hose and run water through the machine with the power off to flush the pump saver out. Reconnect the high-pressure hose and gun, check every connection for leaks at low pressure before you point it at anything, and put a wide tip on before the first pass over paint — the nozzle guide covers which colors should never go near a panel.

If it will not build pressure after a winter in storage, the diagnosis is usually already made. That is what the twenty minutes was for.