Pump losing prime on filter -- following a comedy of errors

[NewHomeowner]

$750 ($250 troubleshooting and $500 pump) poorer and i've learned my lesson....

Turns out I'm an idiot. On the upper side of that large union (plumbing to multivalve), I always put a rubber stopper to prevent any water from going in (which is not necessary since it is upside down)....
Removing that plug solved the problem.

I probably didn't have to buy a new pump, didn't need to buy all these new gaskets, and certainly didn't need anyone to come troubleshoot for a few hours... sigh... Hope someone learns from me!!!

 

[NewHomeowner]

Ok, turns out there is still a problem. Had a guy come and replace all the above ground plumbing with all new valves and unions to the pump. The pump, seals, and gaskets are all brand new. The filter grids in the DE filter are all now also brand new....

Pump now loses prime on filter after about 15-20 minutes.

I read a similar issues from another person on the thread, who unfortunately, ended up finding a leak under ground relating to tree roots.

All of my plumbing is under concrete... so won't be as easy to troubleshoot....

The only saving grace I know of at this time,... is that the large air bubbles and eventual loss of about 1/4 of the water in the pump basket occurs only on the "filter" setting on the multiport valve (replaced in its entirety last year, not just spider gasket). It seems to hold prime on the "recirculate" setting...

When on "filter", I tried to keep the pressure gauge valve open to release water for a while per another post. That didn't help.

1. Do you think it may be a bad DE filter gasket that sits around the belt line of the two filter tank covers (have a Hayward DE-6000)? That is an old gasket, but there is no water loss from the tank.
2. For future reference, could a clogged DE filter also cause what would look like a suction side leak? The pressure on the tank gauge would go up, but would that cause a large bubble?

Thanks all!

 

[Soupy]

Who is "a guy"? My first concern would be with the plumbing job.

 

[NewHomeowner]

Its a one man pool company. He came recommended on NextDoor.com. This is his finished work. He changed the old valves with three new Praher Ball valves and a cracked elbow inside the base of the DE tank (Another ~$250 in parts aone ouch!)

The job seems satisfactory and I don't see any leaks. My one pet peeve with this guy is that he didn't shut off my new multiport valve when switching modes. I just changed that thing. Hope he didn't blow the spider gasket.

At this time, I suspect 1. an old gasket around the DE tank or 2. My new filter grids are clogged (installed yesterday) or 3. an underground pin hole leak.

I'm hoping it's not number three since the pump holds prime in recirculate mode.