Cleaned filter, cant get air out of system

emdoller

Well-known member
Dec 27, 2010
110
El Dorado Hills, CA
I have a pentagram variable pump and 4 c4000 cartridge Hayward filter.

Today I cleaned the cartridges like I always do, put the lid back on, primed the pump with water.

As always, it looked like everything was fine until the pump kicked down in RPM. A rush of air came in. I tried holding the RPM high for a few minutes and it looked great but once the RPM kicked down, air came rushing in.

I decided to pull it apart again (filter and pump top) put it back together and I get the same result.

I let it run for 30min and I still does the same thing.

The pump is working but I know something is wrong. When I shut it off I can hear the air and when the pump goes to the lower RPM setting air rushes in.

I’ve done this plenty of times before and have not encountered this. It was working fine yesterday.

Any ideas?
 

jblizzle

Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
43,232
Tucson, AZ
When you turn the pump on high, are you opening the air release valve on the top of the filter to let the filter purge and fill with water?

Sounds like you are not. And then the air in the filter is compressed, and then when you switch to low speed the air is expanding pushing back into the pump.
 
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emdoller

Well-known member
Dec 27, 2010
110
El Dorado Hills, CA
Thanks for the reply! Yes, I open the valve on the top of the filter. I tried leaving it open as well as closing it once I don’t hear anymore air. I’ll try that again to make sure.

Right now I’m running it on high (3100 rpm) to try and flush it out. It’s running fine but we will see when I turn it to lower RPM.

Stay tuned, and thanks!!

Ed
 

Rocket J Squirrel

Bronze Supporter
Jun 7, 2018
472
Alamo, CA
Yes, I open the valve on the top of the filter. I tried leaving it open as well as closing it once I don’t hear anymore air. I’ll try that again to make sure.
You need to leave the valve open until water rushes out in a strong stream. Otherwise, you’re leaving air in the filter. Just listening is not sufficient. If water never flows out of the valve, that’s a problem.
 

emdoller

Well-known member
Dec 27, 2010
110
El Dorado Hills, CA
Hi

Yes, I left it open till water shoots out. Yes, I lubed the ring on the filter and the pump.

Here’s a video of what happens.


I just ran it for 30min on high and there was no air in the pump basket and none in filter (when I opened it just water). When I shut it off it was fine as I didn’t hear any air.

I then started it like I normally do and when it switched from high to low rpm, air came in. Very strange.

Ed
 

jblizzle

Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
43,232
Tucson, AZ
Can you tell where the air is coming in from? Is it from the suction pipe or from the pump lid?

Perhaps there is a problem with the pump lid and when on high it is pulling enough vacuum to seal the lid, but on low it does not pull hard enough and opens up a large air leak.
 

emdoller

Well-known member
Dec 27, 2010
110
El Dorado Hills, CA
It’s really hard to tell. It looks like the suction side but not 100%.

I just put it in spa mode to bypass the pool suction and everything worked fine.

So that does point to pool suction but I’m not sure why doing what I did would impact pool suction unless it was already there and I haven’t noticed.

Not sure why if it were pool suction it would be a one time burst after the RPM switched.

Very strange.

Ed
 

emdoller

Well-known member
Dec 27, 2010
110
El Dorado Hills, CA
I isolated my two slimmers after seeing that my spa worked. My deep end slimmer door is stuck and it’s running very low hence the issue. Now I need to figure out why the door is stuck.

Stay tuned and as always, thanks for the support!!

Ed