Should be used where 37010 series electric toilets are installed below the waterline line to ensure maximum electric toilet performance and primeability when installing a vented loop in the inlet hose. Install a loop on the inlet plumbing rising at least 8" above the highest waterline level, and installing a vented loop fitting at the top of the loop to stop water siphoning over the loop and flooding the vessel. Solenoid valve attaches directly to Jabsco vented loops and is wired to the toilet's on/off switch. It closes whenever the toilet pump is operated and ensures full pump priming. Use with Jabsco 290150000 vented loop