Air Release kit (Without the solenoid valve)

Version without the electric open/close valve to stop outgoing water:

Explanation: This kit provides a passive air escape route, connecting the top of the pump head to a thru-hull fitting. Air trapped inside the pump is naturally expelled by the pressure from the water intake. While the pump is running, a small stream of water will flow out of the thru-hull fitting, which must always be installed above the waterline.

If the Jet Thruster pump is not priming correctly, it may be due to an air pocket trapped in the pump housing, which prevents the impeller from moving water efficiently. This issue is more common in fast-moving boats that create a vacuum under the hull, drawing air into the system through the bow nozzles. When the boat slows down and the nozzles return below the waterline, an air bubble may form, obstructing proper water flow. It’s essential that the pump unit is installed below the waterline; the Jet Thruster system will not function correctly if the pump is installed above or too close to the waterline.

If your Jet Thruster main pump unit is installed above the waterline, this valve will not solve the priming issue. Solution: Relocate the pump itself. This kit will not solve that problem. The pump must always be below the waterline.

When the pump is installed below the waterline, it benefits from the principle of communicating vessels , allowing water to naturally flow into the pump. However, the low-pressure conditions may still trap an air pocket that cannot be expelled by the inlet pressure alone. The Air Release Valve provides an escape route for this trapped air through a small 1/8-inch opening. This ensures that the water level inside the pump head rises, allowing the Jet Thruster system to operate effectively as soon as it is activated.

Note that the valve itself does not mechanically create a vacuum to prime the pump. Instead, it facilitates the release of air, relying on the water pressure from the inlet side of the pump to push out any trapped air. The high-quality components included in this kit ensure a reliable and efficient venting process.