Here’s what I think might be happening: On your Liberty, it seems you have a single combined tank for gray and black water, not separate ones.
The Headhunter tank sensors might need calibration because they could be misreporting the tank level. When the sensors show 15%, the tank might actually be full.
Opening the gray water bypass allows the contents to drain out onto the ground, which is why it drains when you open it. This part appears to be working correctly.
Here are a couple of steps to address the issue:
- Calibrate the Tank Sensors: Headhunter has a straightforward calibration process. On the remote panels for the tank level sensors, you’ll find dip switches. You should calibrate these sensors when the tank is empty and then when it’s full. If this calibration solves the issue, it could fix the problem.
-
Check the Street Elbows: There are quarter-inch push-in street elbows at the top of the tank where the airline connects. If these elbows fail or leak air, it could cause incorrect tank readings. It’s worth inspecting these fittings first. If they are faulty, replacing or re-seating them should help.
-
Inspect the Micro Compressors: If you have micro compressors (small air compressors used for the system), ensure they are functioning correctly. Look for a red reset button and a green light to verify operation. There are usually three of these, resembling small fish tank compressors.
-
Headhunter systems can be complex and sometimes overpriced, but their calibration procedure should be in the house manuals or available online.
If the street elbows are leaking, trimming a bit off the end of the airline and reinserting it might resolve the issue.