Troubleshooting noisy Hayward pump

[Greenhound386]

I've been battling an issue with a noisy pump for a few weeks now, and ~90% of the good advice has come from Google searches leading back to this forum. Figured I'd start a thread and see if I can get some more direct advice.

The pump is a Hayward SP3400VSP. I think it's right around 5 years old - the pool was installed prior to me purchasing the home.

It recently started making an intermittently loud noise. It almost sounded like it was running dry and/or air was getting in there, and it sounded like a very loud vibration. If I took off the strainer basket lid, you'd hear gurgling while it purged air (not sure if that's normal), and then the unit would run quiet again for a period of time. Within ~20-30 minutes, it would be loud again. I reduced the pump speed by 5%, and while it was significantly quieter for a few days, the issue came back. I originally suspected bearings, but the intermittent issue is puzzling me. I would have assumed a bad bearing would always sound bad. The issue was getting worse as days passed, so I figured something inside the pump was on its way out.

I've been trying to get my pool guy to take a look at it, but he hasn't. That's another story, and I'm either going to move to a different service provider or do it on my own for a while.

Anyway, I took the pump apart yesterday. It was pretty filthy inside, and I cleaned it all out. I put in all new seals (SPXHKIT100 seal kit). The front bearing was basically dry, so that got regreased. I had a new diffuser, and although the existing one didn't look damaged, I just replaced it since I had a new one and the unit was apart. I also put brand-new filters in, as the previous ones hadn't been cleaned in over 2 years (see comment about needing to replace my pool service provider above). I put it all back together this morning.

No leaks, and for about an hour, the pump sounded just about perfect. There was still a slight intermittent vibration noise, and I can't tell if it's coming from inside the unit or is just something on the outside rattling slightly. Overall, it sounded great, and I had assumed I'd fixed the problem. After the hour, that same vibration / dry sound that I was originally trying to fix slowly creeped back. Crud! Again, I take off the strainer lid, the basket burps air, I put the lid back on, and the filter sounds great as soon as I start it up. Even the slightest amount of debris in the strainer basket exacerbates everything. The pump still sounds way better than it did before I took it apart, but ultimately, I'm having the same issue after a brief period of run time. I can get ~20-30 minutes of quiet operation before it gets loud, and then I have to go let air out via the strainer basket lid to quiet it down before the neighbors get upset about it.

I'm trying to determine if I still have an issue with something within the pump or motor itself, or if air is being introduced into the system, and I'm wasting my time by continuing to diagnose just the pump itself.

 

[mas985]

Welcome to the forum!

Sounds like you may be getting air in the pump basket. Can you see any air through the clear cover? There should be none.

Also, you cannot run a pump without it's cover or it will not pump water so don't do that.

If you are getting air in the pump basket and it is intermittent, you might have a problem with the skimmer weir door OR the pool level is to low. Check to make sure the skimmer weir door swings freely and that the water level is at least half way up the skimmer opening.

 

[Greenhound386]

Welcome to the forum!

Sounds like you may be getting air in the pump basket. Can you see any air through the clear cover? There should be none.

Also, you cannot run a pump without it's cover or it will not pump water so don't do that.

If you are getting air in the pump basket and it is intermittent, you might have a problem with the skimmer weir door OR the pool level is to low. Check to make sure the skimmer weir door swings freely and that the water level is at least half way up the skimmer opening.

There's almost no air in the strainer basket when looking through the clear cover - maybe a couple of bubbles or so here and there.

The water level is perfect, and the skimmer weir door is operating correctly.

 

[mas985]

Can you post a video of when the pump starts making the noise and show the pump basket lid?

 

[1poolman1]

I've been battling an issue with a noisy pump for a few weeks now, and ~90% of the good advice has come from Google searches leading back to this forum. Figured I'd start a thread and see if I can get some more direct advice.

The pump is a Hayward SP3400VSP. I think it's right around 5 years old - the pool was installed prior to me purchasing the home.

It recently started making an intermittently loud noise. It almost sounded like it was running dry and/or air was getting in there, and it sounded like a very loud vibration. If I took off the strainer basket lid, you'd hear gurgling while it purged air (not sure if that's normal), and then the unit would run quiet again for a period of time. Within ~20-30 minutes, it would be loud again. I reduced the pump speed by 5%, and while it was significantly quieter for a few days, the issue came back. I originally suspected bearings, but the intermittent issue is puzzling me. I would have assumed a bad bearing would always sound bad. The issue was getting worse as days passed, so I figured something inside the pump was on its way out.

I've been trying to get my pool guy to take a look at it, but he hasn't. That's another story, and I'm either going to move to a different service provider or do it on my own for a while.

Anyway, I took the pump apart yesterday. It was pretty filthy inside, and I cleaned it all out. I put in all new seals (SPXHKIT100 seal kit). The front bearing was basically dry, so that got regreased. I had a new diffuser, and although the existing one didn't look damaged, I just replaced it since I had a new one and the unit was apart. I also put brand-new filters in, as the previous ones hadn't been cleaned in over 2 years (see comment about needing to replace my pool service provider above). I put it all back together this morning.

No leaks, and for about an hour, the pump sounded just about perfect. There was still a slight intermittent vibration noise, and I can't tell if it's coming from inside the unit or is just something on the outside rattling slightly. Overall, it sounded great, and I had assumed I'd fixed the problem. After the hour, that same vibration / dry sound that I was originally trying to fix slowly creeped back. Crud! Again, I take off the strainer lid, the basket burps air, I put the lid back on, and the filter sounds great as soon as I start it up. Even the slightest amount of debris in the strainer basket exacerbates everything. The pump still sounds way better than it did before I took it apart, but ultimately, I'm having the same issue after a brief period of run time. I can get ~20-30 minutes of quiet operation before it gets loud, and then I have to go let air out via the strainer basket lid to quiet it down before the neighbors get upset about it.

I'm trying to determine if I still have an issue with something within the pump or motor itself, or if air is being introduced into the system, and I'm wasting my time by continuing to diagnose just the pump itself.

If it was a bad/dry bearing, grease won't solve the problem, it needs to be replaced. The bearings are sealed, but a leaking seal can wash the lube out of them. Then either the balls themselves, the race, or both will wear very quickly and there is no fix, just replace.

 

[Greenhound386]

Can you post a video of when the pump starts making the noise and show the pump basket lid?

I can certainly try! Will do it tomorrow or Sunday and can post it up.

Also, I guess I should be more clear about my question: I am trying to determine if an air leak on the suction side could be correlated to pump noise. And can air 'accumulate' in the pump where it doesn't make noise at first, but then starts after ~20 30 minutes of run time?

On that note, I do now notice a few very small bursts of bubbles from the returns going into the spa. I suppose that would point more specifically to an air leak, but troubleshooting that is really well documented on this site, and I'll start there. But, still want to know if that's correlated to the pump noise or not, as that's ultimately what I am trying to remedy.

 

[proavia]

Post the serial number of the pump.
Someone may be able to then tell you the manufacturung date of the pump.

What RPM or RPMs are you running the pump at when the noise is present?
What RPM has the pump been running at when you notice the air bubble under the pump basket lid?

 

[1poolman1]

I can certainly try! Will do it tomorrow or Sunday and can post it up.

Also, I guess I should be more clear about my question: I am trying to determine if an air leak on the suction side could be correlated to pump noise. And can air 'accumulate' in the pump where it doesn't make noise at first, but then starts after ~20 30 minutes of run time?

On that note, I do now notice a few very small bursts of bubbles from the returns going into the spa. I suppose that would point more specifically to an air leak, but troubleshooting that is really well documented on this site, and I'll start there. But, still want to know if that's correlated to the pump noise or not, as that's ultimately what I am trying to remedy.

Air can be pushed through the pump along with the water and will then be released from the filter by its internal air-relief screen (most sand filters don't have that). Air will not remain in the pump and "accumulate."

 

[Greenhound386]

@mas985 Uploading the video now and will post that shortly.

@proavia The noise happens at all RPMs. The pump will run fine and sound great when I burp the air from the strainer basket and then run it. It will be loud for a moment, and then it quitets down and sounds totally normal as soon as the strainer basket fills with water. Within about 20-30 minutes, the pump sounds like it has air in it and is running dry, but the strainer basket is still full of water. Again, I can essentially reset the process by removing the strainer basket lid, allowing the air to burp out, and then restarting the system. The pump basket also presents the same amount of air / water no matter what RPM. You'll see this when I post the video; there's little to no air in the basket.

I can't tell if I am trying to diagnose a single issue with air getting in from the suction side, a hardware issue with the pump, or both.

 

[mas985]

I can certainly try! Will do it tomorrow or Sunday and can post it up.

Also, I guess I should be more clear about my question: I am trying to determine if an air leak on the suction side could be correlated to pump noise. And can air 'accumulate' in the pump where it doesn't make noise at first, but then starts after ~20 30 minutes of run time?

On that note, I do now notice a few very small bursts of bubbles from the returns going into the spa. I suppose that would point more specifically to an air leak, but troubleshooting that is really well documented on this site, and I'll start there. But, still want to know if that's correlated to the pump noise or not, as that's ultimately what I am trying to remedy.

Yes, the pump noise most definitely could be due to an air leak especially if it is significant. When a pump loses prime, it sucks a lot of air which can make a lot of noise. I will be able to tell more after I see the video.

 

[Greenhound386]

Here's a link to the video.

The video starts with the pump having already run for a period of time, and it is now very loud and sounds like it is dry. In the video, I demonstrate the process of removing the lid, burping air from the strainer basket, and restarting the pump.

Yes, the pump noise most definitely could be due to an air leak especially if it is significant. When a pump loses prime, it sucks a lot of air which can make a lot of noise. I will be able to tell more after I see the video.

So that video was taken yesterday. Video starts with the pump after it has run for a while, and it's loud. I proceed to turn it off, take off the strainer lid, let the air burp, and then it sounds normal when I start it back up.

Funny enough, started the pump today, and it ran for hours and sounded great. It eventually turned off automatically since it is set on a timer, and I turned it back on within 5 minutes. Noise immediately returned. Did my normal routine with the basket lid, and let it run for several more hours with a normal noise output. The random nature of the issue is completely puzzling me.

 

[Greenhound386]

2 more puzzle pieces, and please excuse my ignorance. Only had the pool for 3 years and have had someone taking care of it the entire time. Lots of issues, and trying to learn some stuff myself while I look for a replacement provider.

This video shows what sometimes happens when I turn the pump off. Air will just start bubbling into the strainer. Sometimes it doesn't do this until I remove the strainer lid.

This video shows what happens when the pump is being loud, and I toggle the vacuum switch. Vacuum is plugged into wall of the pool. Moving the lever to the left (towards the ground) reduces vacuum suction, and pulling the lever up opens the valve and increases pressure. Moving that valve back and forth a tad will make the pump loud, or return it to normal volume.

 

[mas985]

The gurgling and bubbling in the filter is normal when you remove the pump basket lid. That is just air entering the plumbing.

The noise after the restart is not normal. It sounds more like interference than it does air. Have you removed the motor/impeller assembly from the wet end to look at the volute and inspect the impeller for any interference?

The second video indicates an air leak somewhere. Probably in the pump lid gasket.

 

[1poolman1]

Here's a link to the video.

The video starts with the pump having already run for a period of time, and it is now very loud and sounds like it is dry. In the video, I demonstrate the process of removing the lid, burping air from the strainer basket, and restarting the pump.

So that video was taken yesterday. Video starts with the pump after it has run for a while, and it's loud. I proceed to turn it off, take off the strainer lid, let the air burp, and then it sounds normal when I start it back up.

Funny enough, started the pump today, and it ran for hours and sounded great. It eventually turned off automatically since it is set on a timer, and I turned it back on within 5 minutes. Noise immediately returned. Did my normal routine with the basket lid, and let it run for several more hours with a normal noise output. The random nature of the issue is completely puzzling me.

The noise you hear is a pump that is running dry. You are not "purging" air when you open the pump lid, but allowing water to drain from the system, both down the suction line and out of the filter and it sounds like an old water cooler that "glugs" when you fill a water cup as air enters. There is definitely some bearing noise in that motor.
Look for an air/suction leak. Could be in the pump-lid O ring that may need to be lubed/replaced. Could be in the valve in front of the pump needing the stem and lid O rings lubed or replaced and lubed.

 

[Greenhound386]

Thanks for the replies!

Regarding the pump lid: I put in a brand-new O-ring (with Jack's lube from Hayward), and that didn't seem to change anything. I swapped the lid from the pump basket from my waterfaill / slide feature, and it's doing the same thing. I'm gathering that the air leak must be from another component, or I suppose there could be an issue with the basket itself and not the lid. I'll troubleshoot the air leak further.

On a related note: pump has been running for 2.5 hours so far today and sounds fine. It 'runs dry' for a second or two at a time here and there, and it's very intermittent. Curiously, the basket has a much larger air bubble than usual and is frothing a lot at the top.

 

[mas985]

On a related note: pump has been running for 2.5 hours so far today and sounds fine. It 'runs dry' for a second or two at a time here and there, and it's very intermittent. Curiously, the basket has a much larger air bubble than usual and is frothing a lot at the top.

That is an air leak. You just need find out where it might be. Are you sure there are no vortices in the skimmer and/or the weir door is not stuck. That type of intermittent large air leak is usually from the skimmer.

Also, have you lubed the union in the front of the pump?

Also, in first video and the first part of that video, it looked like the pump basket was completely full of water while it was making that noise. Was that the case?

 

[Greenhound386]

That is an air leak. You just need find out where it might be. Are you sure there are no vortices in the skimmer and/or the weir door is not stuck. That type of intermittent large air leak is usually from the skimmer.

Also, have you lubed the union in the front of the pump?

Also, in first video and the first part of that video, it looked like the pump basket was completely full of water while it was making that noise. Was that the case?

No vortices in skimmer, and weir door is operating smoothly. I'll go double-check that, though!

Not sure what 'union in front of the pump' indicates, so forgive my ignorance there. Do you mean the plumbing before it goes to the pump, or the pipe that is connected to the pump right behind the basket?

Your last statement is accurate. The pump basket was completely full of water and just showing the slightest agitation and bubbles along the edges from time to time. Pump has been running for 4 hours now and sounds fine, and yet I have a signicant air bubble and churning in the basket. Go figure. There doesn't seem to be a direct correlation to what the pump basket looks like and noise. Someitmes it makes the noise, and sometimes it doesn't. I almost think it could be somehow temperature-related and some part of the equipment is expanding and contracting with heat. The issue was much more prevalent a few days ago when we had warmer weather. It's cooled down ~10 degrees in the last 24 hours, and the issue has almost gone away.

 

[mas985]

Not sure what 'union in front of the pump' indicates, so forgive my ignorance there. Do you mean the plumbing before it goes to the pump, or the pipe that is connected to the pump right behind the basket?

Yes, that collar is a union. You twist to remove the pipe from the pump basket inlet. There is an o-ring in there that frequently does not seal well. Also, over time, the vibrations of the pump or temperature changes can loosen the collar and it can start to leak.

Your last statement is accurate. The pump basket was completely full of water and just showing the slightest agitation and bubbles along the edges from time to time. Pump has been running for 4 hours now and sounds fine, and yet I have a signicant air bubble and churning in the basket. Go figure.

There might have been something stuck in the impeller that came loose and is no longer rubbing on the diffuser.

There doesn't seem to be a direct correlation to what the pump basket looks like and noise. Someitmes it makes the noise, and sometimes it doesn't. I almost think it could be somehow temperature-related and some part of the equipment is expanding and contracting with heat. The issue was much more prevalent a few days ago when we had warmer weather. It's cooled down ~10 degrees in the last 24 hours, and the issue has almost gone away.

Temperature differences can affect the union. I would check that for looseness and leaks.

 

[Greenhound386]

Yes, that collar is a union. You twist to remove the pipe from the pump basket inlet. There is an o-ring in there that frequently does not seal well. Also, over time, the vibrations of the pump or temperature changes can loosen the collar and it can start to leak.


There might have been something stuck in the impeller that came loose and is no longer rubbing on the diffuser.


Temperature differences can affect the union. I would check that for looseness and leaks.

Thanks, @mas956! The union that connects to the pump basket is a liable culprit, as I recently took that apart in order to do the pump repairs. Gonna go mess around with that shortly.

I did take some handsoap and spread a light film around all of the various unions on the suction side, and there was no obvious leak in any of those areas.

 

[Greenhound386]

The gurgling and bubbling in the filter is normal when you remove the pump basket lid. That is just air entering the plumbing.

The noise after the restart is not normal. It sounds more like interference than it does air. Have you removed the motor/impeller assembly from the wet end to look at the volute and inspect the impeller for any interference?

The second video indicates an air leak somewhere. Probably in the pump lid gasket.

Realized I never replied to this. I did remove the motor and impeller assembly a few days ago when I was installing the new seals. There was nothing blocking the impeller. There was some stuff that needed to be cleaned out (photo below), and I cleaned it thoroughly.

I ended up having to remove the motor and front bell in order to reattach the little bracket that stabilizes the drive shaft. I'm 95% sure that I installed that brack in the correct orientation relative to the bearing, but I couldn't find an exact diagram / parts fiche in order to be 100% sure.