Pump loses prime after passing multiport vale

Hi everyone,

I really need your help! My pump can prime IF I let the outcoming water from the pump pour to the ground, the flow is weak at the beginning but builds up quickly. However, it doesn’t prime if I connect to the multiport valve or slightly raise the pipe so that it’s harder for the initial flow to get out. Can you please let me know what the problems are?

Thank you for kind your help!

Tom

Hello Tom - Thank you for contacting Inyo. We have a few questions. Do you have an inground or above ground pool? What is the make and model of the pump and filter? Has either the pump or filter been replaced recently? What is the size of the pool? Can you post a picture of your equipment setup?

Hello Rob,

Thank you for your response! It’s a 16x32 inground Grecian type pool, so I think it contains about 15000 gallons. No, the pump and filter haven’t been replaced recently.

Here are some photos of my pool, pump, and current equipment setup. When I detach the connector from the pump outlet to the multiport valve, the pump can prime and the water flows and builds up as expected. The bottom diverter valve controls the water from the vacuum. For the other two inlets, I’m not sure which one is from the main drain and which one is from the skimmers. If I open the connector and leave the setup that way, the pump will prime after 5-10 secs. I close the connector, the pressure gage shows 0 psi, the pump sucks water from the inlets, and then nothing soon after.

Thank you for your help!

Your 2HP pump requires a lot of water to keep it primed. It looks like you have two of the three suction lines closed. Try opening up one or both lines. This should allow more water to enter the pump and help it stay primed.

Let us know if that doesn’t work and we’ll try to come up with additional solutions.