Spa pump debacle. Airlock? Bad switch? Who the heck knows.

[ace789nj]

New here, first post. Hoping someone can shed some light on my dilemma before I set my spa on fire.

So a while back one of my pumps started making a horrible sound. I stopped using it right away. Took off the front panel and saw an indication of a water leak where the shaft goes onto the wet end. Pulled the pump. Took it apart and noticed the front bearing had gotten wet. I replaced both bearings and rebuilt the wet end with new parts. Wait, go back...I had trouble putting on the new bearings, brought it into the shop and used a press. (sigh) By the time it dawned on me to pull out a micrometer, I had bent the shaft. So, I ordered a new armature. Got that squared away and put it back into the tub. Turned it on....nothing, just humming. This motor only has a run capacitor so for good measure I checked and replaced it. Same humming. I assumed it was an airlock giving me problems. I loosened the connection going into the wet end, water flows out, didn't really hear air escaping. Same, humming. I took off the back and and made sure the switch was bent forward enough to make contact and that everything was clean. This helped a bit, but not enough. The situation now, the pump will not get going in low speed (filtration) but if I use the controls to turn on the jets, it'll get turning in high speed (but not nearly as fast as it should). I still get the error message, "FLO".

I'm left thinking I still have air in the system but I've bled that coupling over and over. My next step is to pull the thing again and test it (quickly) dry. See if it'll get running without being connected to that wet end. Other than that, I really don't know what else.

 

[mas985]

Is the motor loud when running? Could be bad bearings.

Have you checked to make sure the impeller area is clear (requires disassembling the pump)?

 

[ace789nj]

Thought I hit reply, post vanished.

The motor makes a noise but it sounds more like the humming of an armature trying to move. The bearings are new. When I use s screwdriver to turn the shaft it spins freely. No grinding or binding. I also completely rebuilt the wet end, should be like new. I think if there was something in there I'd feel it when spinning the shaft by hand.

This btw confuses me, the fact the shaft runs freely and easily when I move it by hand. Shouldn't I feel it tight if there was an air lock?

 

[mas985]

No such thing as an air lock for a pool pump. Anyway it could be a contact problem with the centrifugal switch.

Sent from my SM-G900V using Tapatalk

 

[ace789nj]

Forgive me for not knowing but, I'm talking about a 3hp motor for a hot tub. You mention pool pump, are they one in the same?

 

[mas985]

Pool and spa pumps are both centrifugal pumps and a centrifugal pump will overcome almost any air lock.

 

[OldPoolMan]

It sounds as if you went beyond the call of duty on this motor rebuild, but, I'm like that too. You have a motor issue which is related to your pool rebuild. As someone who has rebuilt motors for 30 years, I would suggest that you disassemble the pump and bench test the motor without the pump assembled and check the switch, wire hookups, and the bearing niches on the front and back plates of the motor. The bearings slipping would cause your motor not to fully start.

 

[Ken24]

I have this exact problem with mine. Same thing. Shaft seal was leaking, replaced entire wet end, new bearings. Now pump hums when it tries to start and just shuts off unless I turn it to high. Then it works..... The motor starts up perfect with the impeller off, but as soon as I screw the impeller back on, it just hums, and shuts off even though it spins freely by hand. If I give it a quick turn while it is humming, it starts up perfectly... I also just have one capacitor. Voltage checks out, but when I give it a shake it sounds like it is full of water. I am going to go pick up a new capacitor tomorrow, take everything apart, and reassemble from scratch again... maybe I put the seal together backwards or something.. or the back bearing spacer or thrust washer is seated wrong..stranger things have happened... I'll keep checking this thread to see what you come up with, and share what I did if mine ends up working....

 

[Ken24]

So here is a copy/paste from my thread about the same issue... Hope this helps you or someone else with the same problem......

"Well... here's the result. Took it all apart one more time. Cleaned of the seal, tightened the impeller, replaced bushing and thrust washer in the back, and put on a new capacitor. Started her up, and watched the shaft at the back opening. The motor turned about an eight of an inch, and then rocked a bit, and then motor stopped, and started humming again until I gave it a helping twist with a screwdriver...... Swore a bit..... not as loudly as last time when my wife came outside and told me to be a little less loud....

Removed the through bolts, Took the end cap off of the back of the motor.... Cleaned and Bent the little start switch a little bit forward hoping for some contact.... turned the breaker back on.......................................................... .................................................. SUCCESS !!!!!!!!!! Started like a champ !!!!!!!!!!! So happy !!!!!!"