Pentair Intelliflo - replace motor or keep?

[markw]

I started having a buzzing or vibration type noise over the weekend. Not high pitched. I disassembled the motor tonight expecting to find debris in the impeller but nothing. Then, when getting to the last step with the four bolts on the almond seal plate, after loosening the two upper bolts the plate came loose on its own.
The bottom two bolt receptacles had corroded and failed completely. Likely a result of my salt water over many years of having this pump. I suspect the noise was either due to that poor seal or connection, OR the enamel finish that is corroding off inside and flapping. The motor still runs, but given infiltration and failure of the enamel coating past that seal plate, I'm on the fence about whether to just replace the plate and bolts (cheap), or to replace the entire motor (expensive). I peeled off the failed enamel around the motor spindle area and it's fairly corroded in a manner similar to how an anode looks.
Just looking for some wisdom and/or opinions on what to do. I'm thinking replace the motor, but if they are robust and I get all new seals around it, maybe it keeps going.
Thanks

 

[Jimrahbe]

Mark,

We have seen this before on non-saltwater pools so I would not jump to the conclusion it has anything to do with saltwater..

Seems to be some kind of electrical issue with bonding or grounding, but I am not sure if anyone knows for sure..

If this were my pump I would replace the parts and try it again.. I only say this because I always try the cheap way first, not because I know for sure it is the best option..

Let's see what our other members have to say...

Thanks,

Jim R.

 

[JamesW]

I suspect that you likely had a seal leak, which caused some corrosion.

When the bolt receiver grommets failed, the motor can sometimes pull back just enough to cause the impeller to rub on the seal plate. That might have been the noise that you heard.

Look for evidence of scraping between the impeller and seal plate. Both should show wear.

How old is the pump?

Do you have a picture of the pump?

I think that the motor is partly aluminum or magnesium. Once they begin to corrode, the corrosion can be quite fast.

 

[markw]

Mark,

We have seen this before on non-saltwater pools so I would not jump to the conclusion it has anything to do with saltwater..

Seems to be some kind of electrical issue with bonding or grounding, but I am not sure if anyone knows for sure..

If this were my pump I would replace the parts and try it again.. I only say this because I always try the cheap way first, not because I know for sure it is the best option..

Let's see what our other members have to say...

Thanks,

Jim R.

I suspect that you likely had a seal leak, which caused some corrosion.

When the bolt receiver grommets failed, the motor can sometimes pull back just enough to cause the impeller to rub on the seal plate.

Look for evidence of scraping between the impeller and seal plate. Both should show wear.

How old is the pump?

Do you have a picture of the pump?

Thanks both. It's coming up on 7 years of service. Here are some pics of the motor and some associated parts. Apologies for the quality given had to use a flash with parts outside and dark here now.

 

[JamesW]

You can see the scrap marks on the seal plate where the impeller was rubbing. That's probably the sound that you heard.

That happens when the motor pulls away from the seal plate.

I would test run the motor to see how the motor sounds while running to see if the bearings sound ok.

If the bearings sound ok, I would clean and paint the motor to prevent further corrosion.

Then, get a new seal plate and a new seal and you should be back in business.

 

[JamesW]

Get a good seal, not a cheapo PS-1000.

Get a PS-3865R or a PS-1905.

You can also see wear on the impeller.

You should be able to feel the wear on both parts as well.

You will probably need a housing gasket and diffuser gasket as well.

 

[markw]

You can see the scrap marks on the seal plate where the impeller was rubbing. That's probably the sound that you heard.

That happens when the motor pulls away from the seal plate.

I would test run the motor to see how the motor sounds while running to see if the bearings sound ok.

If the bearings sound ok, I would clean and paint the motor to prevent further corrosion.

Then, get a new seal plate and a new seal and you should be back in business.

Thanks. I just ordered the plate and new seals. Pentair 071734S, and the housing gasket and diffuser gasket. All genuine Pentair. Friday delivery. Weather permitting, I'll clean the rest of the flaking enamel off and lightly sand the corrosion, then mask and hit it with rustoleum spray paint or will see if there's anything better.

 

[markw]

I’ll try to post some pics later, but wow one of the lower corners of the motor housing is corroded to the point of missing substantial metal material. Fortunately, the bolt hole is still there and appears to be beefy enough. This is the lower part of the motor one of my seals must have failed long ago. I’m actually amazed the motor itself was not compromised. I just cleaned the exterior with a stainless steel brush, wiped it all down and masked things good (especially around the spindle) before painting with some rustoleum. Fingers crossed that once I assemble it all tomorrow with the new plate, seals and bolts, I can get a few more years out of it!

 

[markw]

Here is the motor just before painting - note the corrosion that led to so much metal basically disappearing on one of the bolt holes. Given my experience with this issue, I think it's fair to say that if one has an intelliflo it makes a lot of sense to partially disassemble every 1-2 years and inspect things. I'm guessing my issues could have been prevented with simple seal lubrication or replacement had I caught things earlier. I never saw a visible accumulation of leaking water below the pump, so it must have been very small but still damaging over time.

Here it is primed/painted coat one. You can see the corrosion pitting much more easily.

 

[JamesW]

This is why I always recommend that people get the best seals. The best seals are more expensive, but worth it if it prevents one failure.

Periodically check under the pump with a flashlight. If it's leaking, it will usually be obvious.

 

[markw]

This is why I always recommend that people get the best seals. The best seals are more expensive, but worth it if it prevents one failure.

Periodically check under the pump with a flashlight. If it's leaking, it will usually be obvious.

Yeah I know to do that now. The replacement seals I ordered are Pentair OEM, so hopefully good. I will definitely inspect the pad for any future leaks a lot more closely!

 

[markw]

I reassembled everything yesterday with the new plate and seals. The only thing I had to rig a bit were a couple bolts which I could not source same length locally, so I just stacked stainless washers on them to ensure they did not go too far into the plate's receptacles. I decided to wait until this morning to start the pump up again, in order to give the silicone used around the metal portion of the mechanical seal time to firmly cure. The manual's instructions on reassembly are actually quite good.
Everything appears to be tight, running well, and no longer exhibiting the noise it had before. $75 in parts and some time/sweat sure beats replacing the entire motor in my opinion.
Thanks again @JamesW and @Jimrahbe for your advice in this thread - appreciated!

 

[JamesW]

Nice, glad that you got it working.

 

[setsailsoon]

Mark,

Been following this post with great interest. You've done a great job on this. Problem with pool pumps is the mixed metallurgy as mentioned earlier. They often have cast magnesium alloy front flanges with carbon steel bolts. Cadmium plated or teflon coated would seem more applicable. Then you add a little chlorinated pool water after a seal leak and electrolysis sets in big time. I think these units can last a lot longer with a preventative maintenance program similar to your suggestion. With high-quality seals they can probably even go 3-4 years. Also a little trick I picked up for single speed a two-speed pumps (may work on VS pumps also but I haven't disassembled them for pool pumps). Trick is to remove the long carbon steel bolts that hold the motor together. The metals are sufficiently dissimilar they will freeze into the front flange very quickly and even without a seal leak. You can remove them one-at-a-time and add some anti-seize to the threads then re-install. Most of the time you can do this without removing the pump from the back end of the motor flange. I've found even after a seal leak after 4-5 years of operation this prevents the seizing so the motor can be disassembled for bearing replace pretty easily.

Good luck and thanks for sharing all the great photos of this repair.

Chris

 

[markw]

Update. I must not have caught the situation quickly enough. The motor is starting to make a constant cricket type chirp today, so I’m assuming it’s bearing trouble. I may just have to order the new motor after all.

 

[JamesW]

Possibly bearing trouble. Oh well, it was worth a try.

 

[markw]

Possibly bearing trouble. Oh well, it was worth a try.

Yeah. I don't regret trying to fix it. In any case, I learned how everything comes apart and can easily deal with a motor replacement now if needed.
I'm keeping an eye on it. I shut the pump down last night. When I turned it back on, I heard just a short chirp vs sustained, and now it sounds normal again. I don't know if this means it's just the start of a bearing failure or if something else was going on. I'm definitely not ordering a motor just yet until I can observe things a little longer to see if the sustained cricket/whining type noise returns.

 

[JamesW]

Sometimes a seal can chirp a little from the friction of the faces rubbing together.

So, that might be what you heard.

Hopefully, you will be able to get some more time out of the pump. They're not cheap.

 

[Mayorb]

I have seen this failure a number of times.
Val-Pak makes an aftermarket seal plate for the Whisperflo pumps. (That's what the VS pumps are based on)
I won't install a Whisperflo OEM seal plate anymore.
And in my opinion the 1000 type seal should be phased out, they are not good at heat. Get the ceramic out of the impeller.
200, 201 seals do much better (ceramic is in seal plate).

 

[JamesW]

For a whisperFlo or Intelliflo, the ceramic is in the impeller. There's not much you can do about that.

Why would a seal work better if the ceramic is in the seal plate?

Why reference the 200 or 201 seals as they won't work on Intelliflo or whisperflo and they are the same quality as the 1000?

The PS-3865R or a PS-1905 are the best choices.

There are 3 levels of seal quality.

Basic seals have Buna Elastomers, a Phenolic (Plastic) Primary Ring and a Ceramic Seat. Theses are junk due to the primary ring composition.

"Ozone/salt" seals have Viton Elastomers, a Carbon Primary Ring and a Polished Ceramic Seat. These are acceptable.

The best seals have Viton Elastomers, a Silicon Carbide Primary Ring and a Silicon Carbide Seat.