spa jet issue

[vegas-doug]

Having some trouble with my spa jets. I have 2 pentair vs pumps, one pump runs water thru the filter and heater and controls 4 spa jets while the other pump handles only 8 spa jets (this pump is run only at one speed thru the Intellicom II). Both lines are hooked up to the same 2 hp blower. The trouble I'm having is that when I turn the spa on it seems to have low flow out of the jets on all 12 jets. Once I turn the blower on for a few seconds and then back off the jets are much more like you would expect from 2500 rpm 3hp pump.

Any thoughts on why I would need to turn the blower on for a few seconds to allow the pumps to power the jets properly?

Also, last night it seemed to happen while using the spa. After an hour or so the jets got weak even though both pumps were running at 2500 rpm. Was fixed by turning on and off the blower.

 

[kadavis]

Are all 12 Jets connected to the 1 airline? It's all dependent on how your builder set up the Jets, what kind of Jets were installed, and if the blower was even necessary. If the blower can be removed try running the Jets without it. You could also play with the rpms to see if that doesn't improve them. Sometimes the spa is specd with a Blower and sometimes the Builder uses them to make up for inadequate action

 

[vegas-doug]

Thank you.

The jets are on two different air lines but they were t'd into one another to connect into one blower. I can shut off either side by using the ball valves. The jets are just standard eyeball type. I have tried with only the pumps and that is when the issue happens, until I start up the blower. Then I can shut the blower off and the jets are all much better than before I turned the blower on. The rpm's seem fine as they are over 2500.

I'm starting to wonder if the 8 jet pump is not priming since it is connected to the intellicom II and not the easytouch panel.

 

[mas985]

The air lines are filled with water and the blower helps to clear them out so you get both air and water together which looks more like a normal spa. On most spas, blowers are meant to be run most of the time. Had the PB designed the spa correctly, a blower might not have been needed at all. But few PBs understand hydraulics so their designs are usually lacking.

However, if there is an obstruction in the lines, that can also cause some issues.

Does the filter pressure change at all when the flow rate decreases?

Also, are you sure the flow rate is decreasing and not just the air bubbles?

 

[vegas-doug]

Will have to check the psi on the filter.

Sometimes my wife wants the blower off as it is more calm and only uses the pumps to power the jets but other times I like to get the blower going for extra power.

Yes, it is definitely not just the air bubbles.

 

[vegas-doug]

Think I figured this out. It seems the 8 jet pump that is run thru the intellicom 2 unit does not run the startup prime, it just goes directly to the 2500 rpm that it was programmed to. I set it to 3000 rpm and now I don't have this issue as it is basically almost priming speed.

The 4 jet main pump that runs thru the filter also seems to be working better now, no idea why.

I guess my main takeaway would be that controlling a pump with the intellicom 2 does not seem to allow the pump to prime unless the speed is set to a high enough speed.