Keeping having to prime. Help!

stevepoxy

New member
Jul 7, 2017
4
Peachtree City, GA
Hello,

We keeping having to prime our pump to start pulling in water almost every time we turn it on. This just started happening this summer. We have a Hayward sand filter that we installed brand new two years ago. We didn't open the pool last summer, but the summer before that, we only had to prime once per season, as usual.

But this summer, we have to prime it almost every time, including when we backwash. Did I open the pool wrong by chance? What I mean is, before we had the sand filter, we a DE filter that had a valve on top, and when you opened the pool, you would open the DE's valve to get the air out, and once water started coming out, you would close it. Well, our sand filter has nothing like that (Hayward sand filter with a multi-port valve that came with the filter), so when I opened it, I simply screwed back on the drainage cap near the bottom of the sand filter and turned it on after priming it. Is it possible that I have air in the filter or something? Did I open it wrong?

I should mention that our pool is large, 31,000 gallons, and has a Pentair pump that is only about 3-4 years old and it still works fine. There's no leaks in the pluming that i can see, and we don't lose any pool water even when the system is running for days straight, so I don't think I have an underground leak either. Any ideas why I have to keep priming this thing?

-Steve J
 

needsajet

TFP Expert
LifeTime Supporter
Jan 4, 2016
4,698
Sydney, NSW, Australia
Welcome to TFP! Good to have you here :)

It should prime itself (self-prime), even if the system drains back. It can take a few minutes sometimes. I only mention that to save you the bother in the meantime.

If it's draining back, it may be possible to stop that. Start with easy stuff like the pump basket lid. Is the o-ring lubricated before putting it back on? Another possibility is the backwash line with a slow leak, or the collar on the multiport valve not being tight enough. Do you see any slow water leaks anywhere?
 

stevepoxy

New member
Jul 7, 2017
4
Peachtree City, GA
Welcome to TFP! Good to have you here :)

It should prime itself (self-prime), even if the system drains back. It can take a few minutes sometimes. I only mention that to save you the bother in the meantime.

If it's draining back, it may be possible to stop that. Start with easy stuff like the pump basket lid. Is the o-ring lubricated before putting it back on? Another possibility is the backwash line with a slow leak, or the collar on the multiport valve not being tight enough. Do you see any slow water leaks anywhere?
Thank you for replying! Yes, it is draining back, in that when I shut the pump off, I can hear water rushing out of the sand filter, and, sometimes, I see water coming back up through the skimmer baskets.

I don't see any leaks in the multipart valve, but I haven't inspected the o-ring. I will look at it today and apply some lube to it too and will report if that helps or not.

-Steve
 

Geebot

Well-known member
Aug 19, 2013
895
O-ring is definitely worth checking. My wife and I split pool tasks 90/10 (I'm 90). The other day she decided to backwash (for the first time ever) while I was at work. She did a good job but called me because pump wasn't priming when she restarted. Suggested she check o-ring as a first step, and it turns out that she had not properly seated the cover. May not be your solution but easiest place to start.
 

mikegmi2

Well-known member
Jun 7, 2019
61
Michigan
Welcome to TFP! Good to have you here :)

It should prime itself (self-prime), even if the system drains back. It can take a few minutes sometimes. I only mention that to save you the bother in the meantime.

If it's draining back, it may be possible to stop that. Start with easy stuff like the pump basket lid. Is the o-ring lubricated before putting it back on? Another possibility is the backwash line with a slow leak, or the collar on the multiport valve not being tight enough. Do you see any slow water leaks anywhere?
Hello - When you say 'collar on the multiport valve not being tight enough', do you mean the 10 bolts that go around the perimeter need to be tightened? I noticed this year that I constantly have water in the area where the handle meets the housing of the valve. It's not dripping, but given all my equipment is located in a pool house, the water must be coming from somewhere so I guess I need to tighten these bolts? Or perhaps I need to get a new spider gasket?
 

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