Your pressure washer won't build pressure. Six things to check, in order.
A machine that runs fine but won't make pressure is the single most common call we get, and it is almost never the pump.
The reason to go in order is money. The cheap fixes are also the likely ones, and people routinely buy a $600 pump to solve a $9 problem. We have watched it happen enough times to write it down.
- Your water supplyStart here, always. A pump that cannot get enough water cannot make pressure, and it will cavitate itself to death trying. Check that the hose bib is fully open, that the garden hose is not kinked under the truck, and that the inlet screen is not packed with sediment. A 5 GPM machine needs more than 5 GPM at the inlet — plenty of well systems and old spigots will not deliver it.
- The nozzleAn eroded orifice is the most common cause of gradual pressure loss, and nobody suspects it because nothing looks broken. Nozzles wear from the inside out. If pressure has drifted down over a season, put a new nozzle on before you touch anything else.
- The unloader valveIf pressure comes and goes, or the machine spikes when you release the trigger, look here. Unloaders stick, the seat wears, and the spring loses tension. Do not adjust the pressure up to compensate for a failing unloader — you will take out the pump doing it.
- Air in the systemPulsing at the gun usually means air, not a failing pump. Shut down, open the trigger, and let water run until it flows steady with no spitting. If it keeps drawing air, you have a leak on the suction side — a loose fitting, a cracked inlet hose, or a bad o-ring.
- The chemical injectorA downstream injector stuck open bleeds pressure continuously. Pull it out of the line and test the machine without it. If pressure returns, you have found it. Injector check valves are a wear item and people forget they exist.
- Pump packings, then the pumpOnly now. Water weeping from under the manifold means packings, which is a rebuild kit and an afternoon — not a new pump. Actual pump replacement is last because it is almost never the answer. If you have genuinely gotten here, call us before you order anything.
The one that gets people
Cold weather. A machine that made pressure fine in October and will not in January often has nothing mechanically wrong with it — there is ice in the inlet line or a partially frozen pump head. Thaw it fully before you diagnose anything, and never run a pump you suspect is frozen. That is how a $9 problem becomes a $600 one.
If you have worked the list and you are still stuck, bring it in. We are at 665 Laura Ct in Lewisberry, and diagnosis on the bench is free. We would rather tell you it is a nozzle than sell you a pump.