Engine will not Idle
There may be an issue with the carburetor. The carburetor may just need to be cleaned or repositioned. Any blockages here will cause insufficient fuel. Further, gas should not be left in the power washer for more than thirty days. If there is gas in there for thirty or more days, remove and clean the carburetor out. If the engine still will not idle, the carburetor may need to be more thoroughly cleaned, or replaced. An engine not idling can also be caused by the unloader valve. The unloader valve is meant to divert the flow of water from the pump to the loop when the trigger is released. The valve allows the water pressure to be high while keeping the pressure in the actual pump low. The cause of the engine not idling here is because the pressure is too high in the pump. In this case, the valve needs to be inspected and replaced.
If the power washer is leaking water it may be due to the inlet seal. The inlet seal is meant to seal the connection between the hose and the inlet. This coupling can wear and break, so if the leak is coming from the hose connection then the inlet seal may need replacing. Another cause of leakage is from the piston seals. If the leak is coming from the pump and there isn’t any cracks in the pump then the piston seals either need replacing or readjusting. Further, the pump can crack if water is left in the pump and freezes. If there is a leak coming from a cracked pump it is advised that the pump is replaced rather than repaired. Another cause of leakage is the outlet seal. This connects the pump and high pressure hose. If there is a leak coming from this connection the outlet seal may need to be replaced. This is a very simple and cheap repair. Lastly, the thermal release valve can cause water leakage. The thermal release valve keeps the water within the pump at a safe temperature. If the valve is compromised the pump can continuously leak water causing the washer to lose pressure. This replacement is as easy as screwing off the worn valve and screwing on the new valve. It is important to note that this also wears with regular use.
No or Low Pressure
If the power washer is experiencing no low pressure, first check the hose. Make sure there aren’t any kinks and that the water is on high enough. Most washers require a continuous water supply of 4L per minute to operate. If there are no kinks and the water source is good, unhook the hose and see if there is any blockage or debris. Another cause of low to no pressure is the unloader valve. The unloader valve regulates the water pressure and can be adjusted to increase of decrease the pressure. This adjustment should be done in small increments. It is recommended that there is a pressure gauge attached the power washer while these adjustments are being made. It is important to note that the unloader valve should always be adjusted with the machine running and the trigger wand pulled, so water can flow through the system. Nozzles is another cause. If the nozzle at the end of the trigger wand becomes worn of plugged is can result in low to no pressure. Check for irregular spray patterns as that may be an indication of debris blocking the nozzle. Nozzles wear over time with regular use and require replacements. Further, if a new high pressure hose was just installed and there is a noticeable loss in pressure, the high pressure hose may be too big and needs to be replaced with the proper size.
Cannot Shut Off Pressure
If the pressure from the wand is not shutting off there may be an issue with the unloader valve, in which it is failing to switch to bypass mode. If the pressure is unable to be turned off the power washer should be turned off immediately. The unloader valve should then be replaced or fixed if seen to be malfunctioning. The trigger wand may also cause the inability to shut off pressure. There is a mechanism in the trigger wand that causes the blockage of water when the trigger is released. When pressure increases within the trigger wand the bypass should initiate; however, if it does not switch to bypass there is a problem with the trigger wand and it needs replacing. The trigger wand wears with regular use.