Jetted Tub Issue

Hey Guys

Hoping someone can help me out. I don't know much about jetted tubs, except for what I've been recently reading up on.

I purchased a home 4 years ago that had a jetted tub in the master bathroom. I tried it a few times and always got a humming sound from the pump without any water flow from the jets. I have recently got it to work by plunging the water intake, however I'm looking to have it work without having to plunge it.

I was able to use a screwdriver to move the drive shaft. It moved easily. I'm assuming no corrosion.

Pump is a 3/4 HP Century Pool Pump Duty.

Tub includes 5 jets. 1 water intake, and 2 venturi air valves.

The water intake is a hydro air 10-6106 (suction cover). I have been unable to remove the cover. I don't see any screws. I'm contemplating using a strap wrench to see if I can remove it and if it needs cleaning.

The pump outtake splits and is hosed around the tub to the jets. Their is a secondary hose above labelled air which I'm assuming is connected to the venturi air valves. I can't see how it is connected to the water system, assuming at the jets.

The only on/off switch is a wall mounted timer.

With the tub full and the timer turned on the only thing that happens is the pump hums. I've researched that plunging the water intake can kickstart the suction. I have successfully tried this. Once the jets activate I can turn on/off the pump as many times as I like. However when I drain the tub, I must repeat the process to get the jets activated again.

Any idea how to prevent having to plunge the intake valve to get the jets working?

 

It would appear that the pump is getting airbound. Under normal circumstances the water should fill the lines and gravity should carry it into the pump.

As far as you know.... when you say the pump hums.... it is actually turning just not pumping ?

The pressurized water is forced thru a venturi at the jets and that allows air to enter from the air controls when they are opened.

 

Thanks PJ.

I'm going to try to get the cover off and see if the lines fills with the cover off. I'm wondering if the inlet holes are all gummed up.

I believe the pump is working correctly, just no water is flowing to the impeller unless you force it by plunging.

 

Update:

I removed the water intake. No clogging was observed.

With the tub filled I slowing released the outtake pump connection. I heard a audible hissing sound with air being released. Once water began dripping I tighten the connection back up.

The jets immediately start when I turned it on.

Unfortunately, once drained and refilled I have the same problem. The pump appears to be air locked every time I drain the jetted tub.

I'm thinking the problem is the pump has been installed too high. The outtake piping is at the same height as the overflow valve in the tub. If i remember my engineering fluid dynamics course that means the hydrostatic pressure isn't great enough to clear the air out of the top of pipe.

I don't think I'm motivated enough to lower the pump and piping with the limited access.

 

I was able to fill the tub past the overflow valve. Took some time to accumulate and the jets started working.

I might play around with it a little this weekend and see if I can work up the confidence to take this on.

 

A agree with the "pump mounted too high" diagnosis.