Manual air bleeder always has air to let off. [resolved]

[RockstarSD]

I have a Pentair Trition II Sand Filter (built before 1991) that came with the house I just bought. I'm currently fighting algae (kind of. I will be REALLY doing it once my TFT kit comes in - just stocked up on 32 gallons of 12.5% liquid chlorine) but I've noticed that I'm not building any real pressure on the tank even though it's running 24/7. A few days ago I accidentally cracked what I think was the original closure dome trying to fix a leak in the manual bleeder valve, so I replaced it as well as the dome o-ring and bleeder o-ring...

When I stayed at the house for three days in the middle of last month, the pressure gauge read about 14-15 psi the whole time I was there. The owner said this was normal, and that if it got up to 19-20 psi he'd backwash and all would be well.

At this point I'm reading between 11 and 12 psi, even during this algae fight (blue cloudy water right now, added about 30 gallons of bleach over the weekend and monday), I never see the pressure rise, backwashing runs "clean" for a few seconds, then cloudy for 60, then "clean" again, but the pressure on the gauge never changes.

I see no visible signs of leakage from the dome or bleeder, can't hear any hiss either (though not sure I would because the pump is right there) and whenever I open the bleeder valve - it pretty much never shoots water out, just sort of sputters air for minutes at a time.

I haven't the slightest idea what's going on here. Thoughts?

 

[Bama Rambler]

Re: Manual air bleeder always has air to let off.

If there's that much air in the filter you have to have a suction side leak somewhere. An air leak would also explain the lower pressure you're seeing.

Find and fix that air leak and you'll fix your pressure problem.

 

[RockstarSD]

Re: Manual air bleeder always has air to let off.

I suppose it's possible that I've developed a suction side leak in the two weeks I've owned the house, but it's not very likely... Can anyone think of anything else that might produce similar results?

 

[linen]

Re: Manual air bleeder always has air to let off.

Does you gauge go to 0 when the pump is off?

 

[RockstarSD]

Re: Manual air bleeder always has air to let off.

Yes, immediately.

 

[Bama Rambler]

Re: Manual air bleeder always has air to let off.

It is very likely that you've developed a suction side leak when you stop and consider all the places that a leak can occur. A pump drain plug not sealed completely will cause a suction side leak. The o-ring on the pump basket lid is a very common place. Any fittings (including unions) on the suction side of the pump. Even the weir in the skimmer can cause air to get into the system.

 

[duraleigh]

Re: Manual air bleeder always has air to let off.

There are no other possibilities that I can think of. If there is air in the system, it can only come in through the suction side and you do have air in the system.

 

[RockstarSD]

Re: Manual air bleeder always has air to let off.

Hrm. I haven't done anything with the lines or drain plug, but I have removed and replaced the pump basket several times. I will check the o-ring there for damage and replace if necessary and at the least put some regular o-ring sealing goop on it to help it seal better.

I have never had a problem testing for pressure side leaks (soapy water tells you real quick) but I've never had to deal with a suction side leak. Will the soapy water trick work for suction side?

 

[duraleigh]

Re: Manual air bleeder always has air to let off.

Will the soapy water trick work for suction side?

No. You are sucking air into the suction side....not blowing air out. Check the correct fit for all your orings and gaskets. Unions, strainer basket, etc. Check the drain plugs on the pump basket.

With the pump running, how much air do you observe in the strainer basket?

 

[RockstarSD]

Re: Manual air bleeder always has air to let off.

I assume that the strainer basket is the one in the pump assembly, not the skimmer basket.

I don't really see a lot of air - the flow seems great and is all the way to the top of the view area. I'll see if I can shoot a video of what I'm seeing, and I'll make sure I check all of the everything that I know to check.

 

[duraleigh]

Re: Manual air bleeder always has air to let off.

So if you see ABSOLUTELY no air in the strainer basket (Yeah, that's the right one ) then check the drain plugs....air can be pulled from a loose one and straight into the pump and it is almost impossible to see. Make sure the pump motor is connected snugly to the pump impeller and basket. That is part of the suction side and can be a source of air intake.

 

[RockstarSD]

Re: Manual air bleeder always has air to let off.

I think my symptom was a false positive of a suction side leak, and here's what I did to come to that comclusion.

1) Pressure was almost 20 (up from 13 clean + DE, or 12 w/out DE) so I backwashed and rinsed.
2) Switched the multiport back to filter but did not plug the pump back in yet
3) Took the closure off of the strainer basket, cleaned the strainer, and cleaned and lubed the o-ring and all connecting flat surfaces before putting it back together.
4) Took the closure assembly off the top of the filter. Wiped down the top inside of the tank a bit, and wiped some excess lube off of the fittings for the manual bleeder valve. Also took a look inside the bleeder valve, and lo and behold there were about 3 or 4 pieces of pine needles in the sucker. Used an air blower and some needle nose pliers to clean it up.
5) Re-lubed the o-ring and all flat connecting surfaces of the filter/closure assembly and put it back together.
6) Started pump with bleeder open. Air bled for about 2 seconds then shot a nice steady stream of water. Closed bleeder.
7) Waited about 2 minutes, then opened bleeder. Before I had it fully open it was shooting airless water.

I am pretty sure that the clog in the bleeder valve is what was causing the symptoms - it wasn't that I had metric butt loads of air, just normal amounts trying to escape through a very very tiny orifice.

Thanks for all your help, I am going to consider this resolved for the moment!

edit:
I removed, cleaned, teflon taped, and put back in the water and sand drainer plugs from the filter canister. I also tightened the two drains on the pump. I didn't see any signs of leaking on them, but figured why the heck not.