Spa pump 1 issue -- doesn't complete the prime

[chef_m]

2 speed 240v pump, Balboa control pack

Hi. Inherited this spa from Aunt; has been working fine for 18 mos (after I finally figured out that the motor speeds had been wired backwards).

So today, I go to heat it up and change into "St" Standard mode. The main pump cuts on for a few seconds just like it does when it's checking the temp or priming. 20 mins later, still doing the same thing -- cycle on for 5 secs, off for about 60 secs. Press the control panel for Jets 1, and all I get is the "click" on the control board or solenoid with no pump action.

Ah, I actually have seen this behavior once before. Threw the breaker and waited. Reset the spa. Priming starts, control panel shows "Pr", get the same results after 10 mins.

So here's the question: when the board tells the motor to start, is their some sort of relay or solenoid on the motor itself that starts the pump? (I'm thinking about a starter on a car -- there's a solenoid that spins up to engage the motor.) I don't understand why the pump *does* produce water flow during part of the cycle but will not energize into low or high speeds and normal flows.

Can anyone please explain that?

And of course, this is birthday weekend and planning on having folks over.

 

[JasonLion]

Pumps often have an internal start switch, which turns off start mode as soon as the shaft is turning.

Electronic control systems also often have a startup mode (priming). Most of them just have a delay to allow the pump to prime, but a few have a flow sensor and wait until they detect water flow before going to run mode.