Air in the return line, normal or not?

[Squeeken]

I just installed a new Intelliflo variable speed pump to replace my single speed. I've never had a pump that can run this slow before so I'm not sure if the air bubbles I'm seeing are normal or not. I've got the pump set up to run at 2500 RPM from 8:00am to 11:00am for the pool vac and then 1000 RPM from 11:00am to midnight for circulation. The pump is off from midnight to 8:00am. I have a spa that spills over into the 18000 gal pool and no other water features.

When the pump is running at 2500 RPM, I can see some small bubbles in the pump intake basket. When the pump runs at 1000 RPM, there is an air bubble about the size of a quarter in the basket and it just sits there at the top while the water flows through the basket. When the pump is running at 1000 RPM, I see grape size bubbles slowly rising from the return jet furthest from the pad and I can hear what sounds like trickling water from the return lines near the heater and chlorinator. If the pump has been running at 1000 RPM for awhile and then I bump it up to 2500, as soon as the RPM kicks up to 2500, a big burst of air comes out of the return jet closest to the pad for about 2 -3 seconds. After that, no more bubbles, except for tiny ones that I assume are coming from the chlorinator which is currently set at 50%. Can the chlorinator produce enough tiny bubbles that they get stuck in the lines at the low pressure of 1000 RPM and then get forced out when the high pressure of 2500 RPM kicks in?

My water level is perfect. My pump basket seal is new and on tight. My intake union is new with a tight seal. I don't know what else it could be. I'm thinking that this shouldn't be happening, but I've never had a variable speed pump before. Is this normal?

 

[duraleigh]

It does seem to be fairly normal.....others have reported it. Eliminating every suction leak is often tough. A quarter size bubble is no big deal and you can live with what you are describing.

When you shut the system off, how long will your pump basket hold prime?

 

[Squeeken]

It does seem to be fairly normal.....others have reported it. Eliminating every suction leak is often tough. A quarter size bubble is no big deal and you can live with what you are describing.

When you shut the system off, how long will your pump basket hold prime?

Thanks for your reply duraleigh.

I'm not sure what you mean when you say "hold prime". The pump goes through it's self prime procedure every time it turns on. The pump has been off since midnight; its now 7:00am. In the pump basket right now at the top of the lid is a bubble, the size of a quarter, in each of the six little partitions of the lid, and a bunch of tiny BB sized bubbles in the basket mesh. So if "holding prime" means that the basket stays full of water, then I think it's doing that pretty well. Is that what you mean?

I will watch what happens this morning at 8:00am when the pump comes back on for its daily cycle. It will come on at 2500 RPM. I expect it will shoot out a burst of air from the first return jet, like it does when I ramp up the RPM manually.

This may all be perfectly normal. I never really paid attention to it until now that I changed out my pump. That's what I'm trying to determine. Is this normal, or do I need to keep troubleshooting? I figured you guys are the best source of help for that knowledge. Like many of you, I'm one of those guys that likes to do things himself, and still wants it done right, but it helps to know what "right" looks like.

 

[duraleigh]

Is that what you mean?

Yes. and the fact that it held water in the basket overnight is VERY good. I think you are all set and I would disregard the tiny amount of air you have.

 

[Squeeken]

Is that what you mean?

Yes. and the fact that it held water in the basket overnight is VERY good. I think you are all set and I would disregard the tiny amount of air you have.

Ok, that's great to hear. Now I have two more questions that I almost hate to ask, because the answers seem obvious, but I don't want to make any assumptions.

1. The pool vac will climb the wall and suck air a few times a day. Is that ok for the pump or do I need to prevent that from happening?

2. The Intelliflo manual says, "Install the pump in a sheltered well ventilated location protected from excessive moisture, (i.e. rain, sprinklers, etc.)"
Really? I do not have an equipment room; my pool pad is outside. It will get rained on. In fact, it got rained on last night. Do I need to buy a cover to protect the pump?

 

[Squeeken]

Anyone... anyone...

 

[alanpaul]

At a retail Pool Store, or perhaps online, you can purchase a snap-on plastic cover or cowl that straddles the pump motor, protecting it from rain and sun, yet allowing air to circulate around it. Good luck.