Issues with losing pump prime

[bigdaddy72]

Fairly new to the forum. I have a Hayward super pump and a jacuzzi filter on our 18x36 ig pool. We have a large solar array on our roof controlled by a automatic solar controller. Just some background.

My issue is that last fall I kept losing the prime at the pump. I replaced the check valve before the pump and it helped a bit, but this spring, it was doing it again. I decided that my next course of action was to replace the two filter o rings and see if that helped. It didn't. I can hear a hissing sound coming from the multiport at the top of the filter. Could it be the spider gasket?

 

[duraleigh]

The air you hear is coming from the suction side of your system...somewhere between the skimmer and the pump. Often a bit hard to track down, but find that suction leak and the hissing in the multi-port will stop.

 

[Isaac-1]

You can try either shaving cream around suspect fittings to see where it is sucked in, or you can try spraying water on the suspect fittings and watch for the air bubbles to stop when you get water on the right place.

Ike

 

[Richard320]

Is that hissing sound with pump off? And does it look like you're losing water? The reason I ask is that someone else here in the last few days discovered the multiport was leaking to waste and since it was hard plumbed he didn't see a puddle. If you meet those conditions, I could see you losing water with the pump off, maybe even siphoning it out of the pump and causing it to lose prime.

Otherwise, check the usual suspects: low water level, stuck weir in the skimmer, loose drain plugs on the pump, poor seal on the pump strainer basket, and leaks at the fittings, especially any couplings.
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[bigdaddy72]

Here is the suction side setup for our pool inside our garage. The gate at the left is to our deep end drains, the right to our skimmer. I have heard these types of gate valves are lousy. I replaced the backflow rubber inside the piping going from the pump to the 2 suction lines. Should I just bite the bullet and replace the two gates (I hate them anyways so it won't break my heart if I have to replace them).



I also have 2 ball valves outside my garage in our pool area that also control the skimmer and deep end drains for ease of use when I am vac'ing the pool. I added those two years ago. They are the Lowe's style ball valves. Could it be that they are not made for used in a pool environment?



Here is the pic of my entire pump house setup, including solar piping, etc.



Lee

 

[Richard320]

Wow, lots and lots of couplings. I see a can of shaving cream in your weekend.

 

[bigdaddy72]

Is that hissing sound with pump off? And does it look like you're losing water? The reason I ask is that someone else here in the last few days discovered the multiport was leaking to waste and since it was hard plumbed he didn't see a puddle. If you meet those conditions, I could see you losing water with the pump off, maybe even siphoning it out of the pump and causing it to lose prime.

Otherwise, check the usual suspects: low water level, stuck weir in the skimmer, loose drain plugs on the pump, poor seal on the pump strainer basket, and leaks at the fittings, especially any couplings.
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I had an issue a few years ago that I was backflushing to waste was trickling out. I plumbed a shutoff right at the waste line to eliminate that possibility of a leak.

Yes, the hissing is when it starts to back drain. Very quiet.

Let me ask a supremely dumb question...I have been fixing a leak on the pool and dropped the level below my skimmer. So far, I have been using just the deep end side to get it filtering. The gate and ball valves are both closed on the skimmer side. Could it be that the gate valve is causing the issue? Wouldn't the check valve catch and not allow it to back drain.

 

[bigdaddy72]

Wow, lots and lots of couplings. I see a can of shaving cream in your weekend.

I may just bit the bullet and simplify it by cutting out the gate valves. and just going straight to outside the garage. I think it would be the easiest and most thorough way of fixing it once and for all.

 

[Richard320]

Wow, lots and lots of couplings. I see a can of shaving cream in your weekend.

I may just bit the bullet and simplify it by cutting out the gate valves. and just going straight to outside the garage. I think it would be the easiest and most thorough way of fixing it once and for all.

Not if they're not the problem.

An hour spent diagnosing it thoroughly could save two or three hours changing good parts unnecessarily. And a lot of money.

 

[bigdaddy72]

How do I do the "shaving cream test"?

 

[Richard320]

Anywhere you suspect a leak, coat it with shaving cream. When it tries to suck in air, it will suck in the cream and you might see it happening. Or it might seal it up and you won't hear that hissing. So do them one at a time.

 

[bigdaddy72]

I assume you do this while the pump is running? I really appreciate you assistance!!!

So if it sucks it in, it my be and o ring or structural with the joints, unions or gates?

 

[Richard320]

I assume you do this while the pump is running? I really appreciate you assistance!!!

So if it sucks it in, it my be and o ring or structural with the joints, unions or gates?

Try it running first. If you start seeing soap suds coming out the returns, you'll know the cream is being drawn in. If you get nothing, try it with the pump off. If the hissing stops or you see the cream developing a hole and it's not dripping off, you'll know it's being drawn in.

My guess is a gate valve stem seal or an O-ring. Just coat each valve one at a time.

One problem is your top-mount filter. You don't develop an air pocket like a sidemount filter would, so if you're sucking air, it's not always obvious.

 

[bigdaddy72]

Got it. If it is the gate valve, is there a way to coat the stem seal? It looked like it is a sealed assembly. I thought it was just a replace type of item...

You mention the top mount filter. I just replaced the two main gaskets last night, but not the spider gasket. I thought that may have been the issue. The pool is 7 years old and has been in great shape. Just minor little issues...

 

[bigdaddy72]

This is the pool outside. Solar panels all over the back of the garage heat it nicely.

 

[bigdaddy72]

 

[Richard320]

Got it. If it is the gate valve, is there a way to coat the stem seal? It looked like it is a sealed assembly. I thought it was just a replace type of item...

You mention the top mount filter. I just replaced the two main gaskets last night, but not the spider gasket. I thought that may have been the issue. The pool is 7 years old and has been in great shape. Just minor little issues...

I don't think your type of valve is rebuildable. But cutting and replacing one is better than replacing all, don't you think?

 

[bigdaddy72]

Absolutely. That gate is glued right into the T section. That would mean I would need to replace both gates and the piece with the backflow preventer going into the pump? Is there any way to salvage the T or is replacement the only option.

 

[Richard320]

Absolutely. That gate is glued right into the T section. That would mean I would need to replace both gates and the piece with the backflow preventer going into the pump? Is there any way to salvage the T or is replacement the only option.

Aren't you getting a little ahead of yourself, here? You don't even know where the leak is yet.

 

[bigdaddy72]

Yes and no. Just trying to be ready with what I may encounter. My pool supply is near work, would typical home center ball valves work fine in pool environments? I can get parts easily today, but may not this weekend.