New pumps, new circuit board - surging jets?

[fflattliner]

I just bought a house that had a broken Cal Spa in a Garden room, so I had the local Cal Spa guy come to fix it...he put in 2 new pumps and a new circuit board. All has been great for a month, now the jets seem to 'surge'. It's hard to explain, but while Im in it, the jets are just blasting away, and all of a sudden they just turn off for only a second...the pumps dont shut off, just the water that blasts out of the jets... its been happening more often over the past week, like maybe once every minute or two while Im in the tub. I thought maybe it would be water level or something, but my sister, a hot tub owner, said that the water is sucked in at the bottom of the tub, so its not like air can get in the lines....any ideas?

[Dr. Spa™ Ret.]

Needs more water.

[sorebikr]

Needs more water.

Positive?  Based on his description of intermittent power to the jets (with not detectable drop in the motors' humm) I'd think something is trapped in the lines.  Either a clogged filter blocking the water flow, or a large amount of air (which could occur is the tub wasn't filled properly after the repair)

[d00nut]

Check your filter.  Dirty filters could cause your pump to starve

[Dr. Spa™ Ret.]

"All has been great for a month, now the jets seem to 'surge'"

"or a large amount of air (which could occur is the tub wasn't filled properly after the repair)"

Positive it ain't that.

"the jets are just blasting away, and all of a sudden they just turn off for only a second...maybe once every minute or two"

Doubt it's a clog or dirty filter.

[fflattliner]

The filter is new too...the Cal Spa guy changed that and he stuck the hose down in a hole to fill it... he told me to do that if I need to fill it. Last night I went in, and not one surge and i havent had time to put any more water in it.

I'll see what it does tonight! Hopefully I will have some time this weekend to add some water...it looks like it needs it.

[d00nut]

It is on a dedicated line I assume?  That could make a world of difference. 

[clover]

Could be a 2" check valve with a broken "flapper" that gets into different positions, at different times, causing the surge to occur, while the motor continues.  Just a thought, but I have replace a lot of check valves within the plumbing arrangement on both suction or return to jets.

Are there any "harmonics", vibration noises, or "motor boating" sounds?

[fflattliner]

Surged like crazy tonight... there is a dedicated line. The 2" check valve sounds interesting if I had a clue at all what anything is on this thing... but I still need to add water. The garden room has no lighting, and by the time I get home from work, cook dinner, and all that crap, its dark...so Saturday will have to be the day I put water in it to see if thats it. 

I appreciate all the help! Im also going to text the hot tub guy that came. I know my new pumps are under warranty!