Hot Tub Pump won't go on low speed (only high turned on manually)

[Lucian119]

Hello everyone, I am reaching out for some help with my spa problem.

I have a Hydropool spa with a Balboa HPEL1K Mach3 (54394-05) control board that has started to act up this fall. I replaced the pump's run capacitor recently as it was not turning on and making a humming sound.

When starting the spa afterwards I had to turn the jets on high a few times before the pump eventually started to run at low speed and the heater turned on. After a couple of days I noticed the spa does not turn on automatically to circulate water and displayed a flow error. I tried running it without the filter and also opened the union at the pump to get rid of any trapped air but nothing helped. 

After a power cycle, I can hear the relay click for the pump but it doesn't start (unless I turn the jets on high a few times while the heater is on). The top controller jet led is turned on.

I also looked at the dipswitch on the board and it matches the schematics attached to the cover. 

Please let me know what I should check on next.

Thanks!

Lucian

[CanadianSpaTech]

If you can access the back of the motor you should see a dust cap right in the middle. Remove the cap and you will see the shaft of the motor with a slot in it. Use a flathead and try giving it a spin when the motor is trying to start in low speed to give it help starting. If it starts up you likely have a bad start capacitor. 

[Lucian119]

I managed to start the motor in low speed by giving it some help turning. I will need to drain the spa and take the motor out to install a new capacitor but it will most likely solve my problem.

Thanks a lot for your help!

Is there any PM I should consider doing on the motor since I am taking it out? It is a Marathon electric 5KCP49UN9096X.

 

[Lucian119]

Hello again, I took out the motor and found out it is a single capacitor electric motor and I already replaced the bad capacitor.

I noticed the impeller was damaged so I replaced it along with both motor bearings.

After re-attaching everything together the pump runs very quietly on both low and high speeds. I was happy to see it started on low speed "on it's own" after releasing the air in the pluming that was due to refilling.

The "joy" was short lived as the next day my original problem returned: tub starts, I hear the relay click and the jet light turns on but pump does not start on low speed. It does start on high speed when pressing the jets button.

Any ideas on what to try next are greatly appreciated.

 

Thanks!

[CanadianSpaTech]

3 hours ago, Lucian119 said:

I already replaced the bad capacitor.

New?... exact part number and ratings as the old one?

Is the new impeller the exact part and HP rating as the old one?

A higher HP rated impeller can cause a pump to trip out but usually when it goes into high speed and it will run for 2, 3 , 4 mins before internal tripping.

Could remove the pump and test run it without water or the drag of water on the impeller and see if it starts on it's own. You said can start it by helping it to spin/start and that leads me to the capacitor.

If you can spin start it in low and then go to high speed when you go back down to low speed does it run normal and only when it it gets completely shut off will it not start again?

 

[Lucian119]

Thanks for your response!

Yes, the replacement capacitor was new, purchased from a local motor repair shop and it has same ratings as the old one.

The impeller is almost the exact part, the only noticeable difference in size is the overall diameter of the new impeller being ~1/4 in smaller on the new impeller.

When I run the pump in high speed, it works in a similar way as the old impeller (similar flow of water through the jets). When I have the heater on and I run the pump for 10-20 sec several times in high speed, it eventually switches to low speed when turning the high speed off.

I just tried to help spin start the pump by hand and couldn't do it so I suspect the impeller might be jammed/pressed in the wet end. I ran the motor without the wet end assembly with no problem but did not run it with the dry wet end assembly on. Guess I should have...

I will try to run it dry and if it doesn't work will look at a different impeller or whole wet end assembly.

 

[Lucian119]

Good news is I disassembled the pump and motor and managed to figure out what the problem was. 

Main problem was the starting winding on my electrical motor was not connected to power due to an improper contact. Once I fixed the electrical contact problem, the motor started fine every time.

The secondary problem was the impeller tail end was rubbing against the wet end housing seal creating additional resistance to the motor starting. I managed to fix that by installing the impeller on the motor shaft first and only after tightening the 4 bolts that connect the wet end to the motor while making sure there is as little resistance possible to the motor shaft rotation. 

 

Thanks a lot for all your help and troubleshooting suggestions!