I'm not sure it's a "not priming" problem, but, when I switch from an empty water tank, as indicated by the pump running continuously without building pressure, to a full tank, the pump doesn't successfully resume its duties: it just runs and runs, and never builds water pressure.
It's a Groco 36800-1000 pump, 20 to 40 psi automatic pressure switch. It's sucking on a line that runs down to the tank manifold about 4' down and 10' away horizontally.
It feeds a 2 gallon Jabsco accumulator, a water heater, and the cold distribution line.
I have found a way to resolve this, every time without fail, and that is to loosen the output line of the pump. What I do is shut off the accumulator, which can be isolated via a ball valve, and then unscrew the polypropylene connector on the output side of the pump. Some water spurts out, but then a lot of air, and then the tone of the pump changes and it starts pumping water again. I hurriedly reconnect it, open the accumulator valve, and all is well; until next time.
I'd really like to know why this happens! It's a Royal Pain to empty the cockpit locker, and dive in to do this.
I'm considering a couple of solutions. But, if there's a basic system problem here, I'd prefer to rectify that.
Ideas:
All analysis and ideas are welcome.
BTW, original plumbing is polybutylene tubing with Parker® O Ring/Grab Ring Tube Fittings. For new work I'm using the same fittings (they're great) and Tamco® RT-55D LLDPE Tubing.
It's a Groco 36800-1000 pump, 20 to 40 psi automatic pressure switch. It's sucking on a line that runs down to the tank manifold about 4' down and 10' away horizontally.
It feeds a 2 gallon Jabsco accumulator, a water heater, and the cold distribution line.
I have found a way to resolve this, every time without fail, and that is to loosen the output line of the pump. What I do is shut off the accumulator, which can be isolated via a ball valve, and then unscrew the polypropylene connector on the output side of the pump. Some water spurts out, but then a lot of air, and then the tone of the pump changes and it starts pumping water again. I hurriedly reconnect it, open the accumulator valve, and all is well; until next time.
I'd really like to know why this happens! It's a Royal Pain to empty the cockpit locker, and dive in to do this.
I'm considering a couple of solutions. But, if there's a basic system problem here, I'd prefer to rectify that.
Ideas:
- install a bleed valve remotely, perhaps in the head, that I can open to bleed the air when this happens;
- install an air eliminator, such as are used in home plumbing systems.
All analysis and ideas are welcome.
BTW, original plumbing is polybutylene tubing with Parker® O Ring/Grab Ring Tube Fittings. For new work I'm using the same fittings (they're great) and Tamco® RT-55D LLDPE Tubing.
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