First, make sure the blue/black adapter attached to the garden hose and NOT the water inlet on the power washer. This is because the adapter has a water check valve. Water will not flow through the blue/blue adapter when the water is turned on when it is not attached to the clear adapter. In order for water to flow through this adapter, the clear adapter must be fully inserted into the blue/black adapter so the check valve is opened.
ALERT: In most cases, the o-ring installed on the clear adapter is too large. If this is the case, the clear adapter is loose/”wiggly” when installed into the blue/black adapter. It is not fully inserted and therefore does not open the check valve. The fix: Get the correct sized o-ring. Short-term fix: apply petroleum jelly to the o-ring and push the clear adapter into the blue/black adapter very hard.
AIR FLOW TEST: Remove both adapters from the unit and the garden hose. Next, insert the clear into the blue/black adapter. Attempt to blow air from the black collar through the blue and clear adapter. If air flow is OK, then reattach to the unit and try again. Water should flow through the GHA