Weird noise/cavitation intermittently w/ pump. No problems suction or pressure side. I'm stumped.

Skypalace

Active member
Jun 25, 2020
31
Seattle area
Here's the other pic I was going to post. 90 degrees to right of the other one. You can see that it's super tight where the electrical goes into the pump. To see there I need my head about where the screw closure is for the cartridge filter, and I need to thread my hands and arms around various pipes to get in there. So will either pull the pump off the intake/discharge to pull it out more, or remove the cartridge filter to give me a bunch of free space.

Below that is the open panel from when I worked on it earlier. Not too bad in there, it was the upper black B lug that was a little loose (could wiggle it). It's drawing 7.4amps per Pentair specs at full load in 240v mode so it's a bit of current but not a ton.

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Skypalace

Active member
Jun 25, 2020
31
Seattle area
Short answer, I think I need a new motor and might just do the whole pump while I'm at it. It's 8 years old. . I'd love some advice.

Any reason anyone can think of to not just order a new motor and seal kit, for half the price of a full new WhisperFlo? Looks like I'd save (~$300 for motor plus seal rebuild kit vs ~$600 for full pump) but I'm confused by part # changes, some of the motors for this full unit show 1hp/1.25 S.F. HP, vs. the 1hp / 1.65 on mine, and a pump part WF-24 vs my WFE-4. See attached pic of the label on my current motor/pump.

I'm all in favor of getting better efficiency etc. if needed, don't think I need to go variable or multi-speed, but willing to consider if it's straightforward (I have an EasyTouch 4 panel). So if a whole new pump, either WhisperFlo 1hp single speed, or a recommended drop-in replacement is the way to go, that works.

Also would love recommendations on suppliers. I'll be self-installing, so warranty coverage and a good service reputation are always good.

Whatever I do, I definitely want to make sure it's a 100% drop-in physical replacement, I have super-tight fittings (see previous pics) and would need to redo chunks of the plumbing if I had to change locations/sizes of input or output unions in any way, because of locations with no room to cut and splice PVC.

Longer version: Back in town and had time to do more diagnosis. I thought I had it fixed by brushing/cleaning/tightening all spade lug contacts. I replaced the 50uF run capacity while I was at it, even though it tested fine, as the top of it was pretty rusty. Worked fine the first 10 times, went to do some other stuff, tried again, back to goofy mode.

This time I was able to get my meter on things while it was happening. The motor is getting 240v fine (measures 245 at the input lugs into the motor). I am getting some pumping into the pool (about 7psi measured but probably only 1/4 of the regular flow) but the motor is clearly pretty unhappy - it's making the noise, impeller clearly not going full speed, I'm only getting 236v across the run capacitor, that should be higher than the input voltage (I got ~270 when it's not in 'goofy mode') And I get a little 'electrical' smell, and to top it off, the motor will overheat and do a thermal shutdown within 5 minutes.

So something bad internal in the motor it seems. New Pentair 1hp 230v part #177450 is $250 range plus $35 for the rebuild kit,, vs. closer to $600 for an all-new pump.
 

Skypalace

Active member
Jun 25, 2020
31
Seattle area
FYI I did pull and did full cleaning of the terminals. Measured 246v between L1 and L2 so it was getting 240v. Was still having the problems, so I decided to replace the motor with a Centrry VGreen 165.