Jandy JXI260K Check Flo

[Barracudamuscle]

Hello,

I’m having new trouble with a 2 year old new install. Pump is variable Jandy 1.65hp with 2” pipes I believe.

I used to be able to run the heater on pool or spa 3450rpm without issues. I’ve found the only way the heater will work is lower rpm like 2400.

History: Pool is 2 years old, one pool store told me to drain it for CY at 110(dam test strips lead me astray), and water hardness 900.

Leslie’s said let it ride, add nophos for high phosphates 900. I did, cleaned the filters, phosphates down to zero life was good.

A week later I had the tiles bead blasted which involved lowering the water level down 6” below the tile line. They had a big pump so I asked them after they vacuumed all the debris to drain it 75%. I finished the drain to empty over the next 2 days as the sealer set for 48 hours.

Refilled pool with the pvc fill(not auto) and another garden hose. Put brand new filters in. Leslie’s said phosphates were 1787 so I added 110 oz of no phos and ran it 48 hours straight and then cleaned the new filters.

Last sample was good, go easy on me I’m done with pool stores and I’m a believer in DIY, just awaiting my test kit and won’t be using anyone else but myself, pool math, and this forum.

Pools been looking great. I went to use the hot tub and discovered the heater never kicked on. I have automation so I disabled that from the equation. The last fault recorded said check gas valve. After clearing that (before I ever got it running today), never saw it again and only get check flow now.

Messing around with pump settings the heater kicked on at 2400 rpm. Anything high I get a check flow fault no matter if it’s set on spa, pool, or pool with waterfalls. For reference all these used to function without issue.

I heard the Versaflow valve opening and closing and can hear the water going in and out of the heater.

At 2400rpm set to pool/waterfall it comes out of the waterfall but about 70% less. Not trickling, not gushing, but enough to clear the raised wall versus running down the wall.

What are your thoughts? Attached are the pressures with the heater on or off with no change from the 3450 rpm. Essentially 8psi off, 12psi heater on.

I appreciate your time and any suggestions!
Pat

 

[Barracudamuscle]

Today I removed the Versoflow valve and didn’t see any obstructions. The valve moved without issues.

While I was in there I removed the thermostat and saw some crud on the face. I cleaned it up, placed it in a pot of water and watched as it heated up and opened. I removed it from the lot and let it close and then placed it back in the hot water to watch it open. No issues there, and the crud that was on it shouldn’t have impacted how it operated.

I used a digital borescope to view up inside the heater core a bit. I couldn’t get in there much, but I didn’t see any obstructions either.

Right now I’m still not sure why the heater kicks off saying check flow anytime the pump is faster than 2400RPM when in the past it’d run at 3400 without issues.

I’m adjusting my salt(from 3800 to 3400) and draining some water out so I can’t ops check the heater yet. I don’t anticipate it to work being there was no smoking gun.

 

[Barracudamuscle]

Follow up:

As expected the heater still won’t turn on with the high pump setting that it used to work on. I’ve emailed Jandy support to see what their thoughts are. Only thing I can think of now is a water pressure switch possibly?

It’s odd that the heater says check flow at high rpm settings but lower settings it is ok. The heater only likes to turn on if it’s on standard pool mode and even low 2400 rpm’s on the Jandy 1.65hp motor state check flow if set to spa and 2400rpms.

It seems as if the pressure switch has a open when pressurized at high rpm, kind of like a potentiometer with an open in a certain spot. I’ve yet to diagnose that being the case, but just brainstorming what’s going on.

 

[ajw22]

Given your CH of 900 I would check the heat exchanger for scale blockage.

 

[Barracudamuscle]

Given your CH of 900 I would check the heat exchanger for scale blockage.

I’m not entirely sure that was a solid value. I took a sample to Leslie’s and they said it’s fine in the 400’s I thought. Needless to say with such varying test results on in the TFT train now and testing my own water.

I’m all for ruling out any issues, what would be the best way of checking for scale blockage?

 

[ajw22]

I’m all for ruling out any issues, what would be the best way of checking for scale blockage?

You need to remove the header and look inside the heat exchanger tubes.

 

[Barracudamuscle]

You need to remove the header and look inside the heat exchanger tubes.

Thank you for taking the time to reply!

So I used my Amazon cheapo video borescope going in the from the straight inlet side of the header to view the header inlets. I didn’t see any blockages or buildups from what I could see.

I removed the side access panel to check the pressure switch and as I grasped the sensor to try and move the adjustment wheel the heater kicked on while set to 3450 and heat. I played around with the adjustment some but ultimately placed it back to where it was, maybe slightly more counterclockwise and verified the heater would shut off with the pump off, operated without issues at 2400RPM and 3450RPM.

I set the hot tub to 100 and it heated up pretty quickly and seemed to have good pressure.

I suspect the pressure sensor was partially stuck or had some issues that now don’t seem to be effecting the operation. I’ll continue to monitor and update with any changes.

 

[ajw22]

If it gets flaky again replace the Water Pressure Switch.