Pentair Intelliflow VF re-primes itself every few hours?

[susa]

new Pentair Intelliflow VF variable speed pump, running 24 hr/day at 15 GPM, about 128-135 watts, 900-1250 RPM.

every few hours, perhaps 4 to 6, the pump switches into Priming Mode from Running Cycles mode (pump programming is set to Start Cycle 00:00 and End Cycle 23:59, thus it is on 24 hours day)

there are no visible air bubbles but of course the basket is not full to the top of the clear top as the water flow is automatically so slow.

when it re-primes, it revs up to 450 watts and 1350 RPM for a couple minutes and then automatically throttles back down to speeds above.

normal behavior?

 

[mas985]

there are no visible air bubbles but of course the basket is not full to the top of the clear top as the water flow is automatically so slow.

There should be very little air in the pump basket at low speed so it may be that you have an air leak and the Intelliflo detects this and kicks into prime mode.

 

[susa]

have opened the clean&clear air release and it spouts water immediately so no air there and the 2 returns have no visible air bubbles.

go figure ?

 

[mas985]

But you did say there was air in the pump basket, correct? If there is too much air in the pump basket, it could trigger a prime.

Also, have you had the opportunity to view the filter pressure right before it goes into prime mode?

Note too that everytime the flow rate is changed in the Intelliflo, it is supposed to go through a priming sequence. So the obvious question is this happening at a scheduled change in flow rate?

 

[susa]

> But you did say there was air in the pump basket, correct?

the flow at 15 GPM and 125-130 watts power is so slow, there is always a small area of airspace at the top of the basket. even after initial prime.

> view the filter pressure right before it goes into prime mode?

filter PSI needle is always at 0. even when priming. if I increase manually flow to 35 GPM or higher, then I can see about 3 psi. once I resume scheduled cycle, psi is back to zero.

> obvious question is this happening at a scheduled change in flow rate?

since schedule is from 00:00 to 23:59 with no letup and only 1 schedule is programmed, the system is literally running 24 hours daily. the 15 GPM exceeds 1 turnover per day but the pump won't run any slower.

( 15 * 60 ) * 24 = 21600 gallons pumped, pool 15000

 

[mas985]

You mentioned in the first post that for 15 GPM, the RPM is between 900 and 1250 which is a 30% swing and would seem to indicate that something is changing during the run period. The RPM should be fairly constant with a GPM setting unless something is forcing the pump to run at higher RPM.

Also, you might try running at 30 GPM for a full 24 hrs and see if it still goes through the priming mode.

 

[susa]

1250 RPM is for initial priming, then it slows down

 

[cadillac]

sounds like it feels that it has lost prime at some point, so it re-primes itself. There could still be water there, but not enough for it to feel primed. I agree with the higher flow to see what happens. On average, 30gpm has been found to be the best overall flow anyhow.