The Unloader valve is designed to respond to an increase in pressure or a change in water flow. ... The trigger shuts off the water flow, causing the unloader valve to re-circulate the water back to the header tank or alternatively back to the inlet side of the pump. This is sending the water into bypass.

How do you know if your unloader valve is bad?

Water leaks and inconsistent behavior are also signs of a potential failure in the near future. González: The typical signal when there is an unloader malfunction is a reduction of flow through the nozzle, which results in pressure loss. Dean: Typical symptom of an unloader failure is a sudden smooth pressure loss.

What happens if unloader valve is bad?

A failed unloader valve can cause high pressure at the nozzle. The unloader valve recirculates water to the pump inlet when the pump is running but the spray wand isn't in use. ... A defective pressure regulator can cause high pressure at the nozzle.