Hayward Heater Issue - Lo error only when in Spa Mode

caseyjones382

Member
Jul 30, 2021
9
new jersey
Hi everyone. I am a new pool owner (came with the house). It is an inground saltwater gunite pool with an attached spa and it is approximately 10 years old.

Last year we had a brand new Hayward H400 heater installed and during the offseason we replaced our filter and salt generator. The new heater worked amazingly well last season and for the start of this season. It mysteriously has started giving us the Lo error but ONLY when we are in Spa mode. When we are in Pool mode it works the way it is supposed to. Our pool guy has flushed the filter a couple times (and it is brand new), so that does not seem to be the issue. Any other things to check?

This may or may not be related (I have no idea but I feel like it might be). But this year our spa also started losing water and it seems to happen (or at least be much more pronounced) when we are running Spa mode. Our check valve was replaced 2 years ago and the pool guy is convinced it is still working fine.

Is it possible these things are related? Either way, any tips on what to check or what to do? Thank you so much for the help!
 
Our check valve was replaced 2 years ago and the pool guy is convinced it is still working fine.

Both symptoms point to the check valve on your spa return line being wonky. Just replace it.

What type of CV is it?

Show us pics of your equipment pad and the CV.
 
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Both symptoms point to the check valve on your spa return line being wonky. Just replace it.

What type of CV is it?

Show us pics of your equipment pad and the CV.

Thank you very much for the reply. Here are 2 pics of the pool pad from both sides (it is screened by some evergreens so it is tough to get it all) and a pic of the check valve.
 

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You can remove the 8 screws in the CV cover and remove the flapper assembly, close it up, and see if your heater works. Your spa will leak down without the flapper. chances are when you examine the flapper you will see it is not moving properly.
 
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You can remove the 8 screws in the CV cover and remove the flapper assembly, close it up, and see if your heater works. Your spa will leak down without the flapper. chances are when you examine the flapper you will see it is not moving properly.
Okay, thank you again for the prompt reply. I apologize in advance but I need to ask you some really dumb questions:

1) Should I turn all the equipment off (either at the breaker or from my jandy remote) before unscrewing the top?

2) Safe to assume the spa will leak down back to where the water level is equal to the pool level and then the remaining small amount of water will heat properly if your CV flapper guess is correct?

3) If it does turn out that the CV is actually okay, are there any other obvious problems? Could some of the jandy valves be allowing water through or anything else?

Thanks so much, really appreciate this. I really like my pool guy but like all pool guys right now he is so unbelievably swamped and understaffed that it is hard to get his attention on this.
 
  • Put your Aqualink in SERVICE mode so the pump is not running.
  • If you loosen the CV screws with the spa filled you will be working with water pouring out of the open top so...
  • Press the VALVES button to SPA DRAIN on the right hand side and lower the water in your spa
Jandy_RS8_Panel.png

  • I forget if the pump will turn on automatically or you need to turn it on
  • When the spa water level is below the returns then turn off the pump
  • Now you can unscrew the top of the CV
  • Remove the flapper and examine it
  • Screw back on the top
  • Press the VALVES button to SPA FILL and turn on the pump if it does not go on
  • Check the CV top for any leaking
  • When the spa is full turn off the PUMP
  • Press the VALVES button to POOL MODE
  • Put the panel in AUTO
  • Turn on your SPA
  • Turn on your HEATER
  • See if it works
  • Check the CV top for any leaking
Report back how it goes and post pics of what you find.
 
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Again, thank you very much. This is really amazing. I just spent some time outside with the junior pool cleaner employee and got some help doing this and some basic troubleshooting.

We opened up the CV and he said it really looks very good. He re-lubricated the flapper and checked the functionality and reinstalled and is convinced that is not the problem with the water loss. I suppose there is a chance it looks okay when uninstalled and from the top after reinstallation but is still letting water through somehow underneath. But the flapper itself looked brand new.

He also noticed the pressure on the filter moving a lot when it switches over to spa mode so he switched the pentair valve to "recirculate" and there was no "Lo" issue with the heater in spa mode when he did that. So he speculates the filter needs to be opened and cleaned properly instead of simply backwashed, but will double check with his boss and have the boss come here to check that out if need be. He thinks it works in Pool mode because the pool can pull through more water than the spa (though that seems strange to me since they both use the same pump and the pipes are the same size).

Unfortunately, when the equipment is in Spa mode I am still losing some water out of the spa. The junior pool guy said there is a chance one of the jandy valves that appears closed might need a new o-ring or something. But he would guess these 2 things just happened to coincidentally appear at the same time and (1) the Lo issue in Spa mode is related to the filter and (2) I need a pressure test / leak detection company because there might be a leak in an underground line from the spa. Given the timing (and my hope not to spend a ton of money diagnosing/fixing it) I am still hoping it is not a mysterious underground leak that showed up mid-season....any thoughts?
 
I doubt you have a pipe leak.

Water cannot get to your Jandy valves to leak if your CV is operating correctly.

Does your spa spillover run when you are in POOL mode?
 
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Yes, spa spillover runs when I am in POOL mode.

Then you have another line to your spa that bypasses that spa return CV that feeds the spa when in POOL mode. That line should also have a CV and maybe a valve to turn it off. That could be where your spa is losing its water to the pool.

To assist you I need to see some better pics of your return side plumbing so I can understand the water flow from the heatr output into the pool and spa.
 
Then you have another line to your spa that bypasses that spa return CV that feeds the spa when in POOL mode. That line should also have a CV and maybe a valve to turn it off. That could be where your spa is losing its water to the pool.

To assist you I need to see some better pics of your return side plumbing so I can understand the water flow from the heatr output into the pool and spa.
Here you go. We have an automatic pool cover, so the the actuator valve at bottom functions to keep the spillover off when the cover is closed but POOL mode is running. Maybe that valve is letting water flow back into the pool when we run spa mode?

On the other side of the equipment pad we have a second jet pump and air blower that are connected to the Spa jets. I included a picture here just in case it is needed, but I would assume not relevant since the water loss happens even with all this off and the water will drop below the spa jets if I leave the keep the spillover off long enough. Thank you again.
 

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Your CV should have been placed by the red circle so it protects both water paths.

The actuator circled in green should be to change POOL or SPA modes.

I think the actuator circled in yellow is for your spillover line. And it is protected by the CV.

If the green actuator is leaking your spa can be draining through it. I cannot not tell in the pic but it does not look like the handle is perfectly centered on the actuator to perfectly close it.

49E738EF-8198-4207-BBA6-A0252F3393BF.jpeg
 
Your CV should have been placed by the red circle so it protects both water paths.

The actuator circled in green should be to change POOL or SPA modes.

I think the actuator circled in yellow is for your spillover line. And it is protected by the CV.

If the green actuator is leaking your spa can be draining through it. I cannot not tell in the pic but it does not look like the handle is perfectly centered on the actuator to perfectly close it.

View attachment 360105
got it - thank you! i will ask my pool guy to check the green circled actuator and let you know what we discover.
 
Your CV should have been placed by the red circle so it protects both water paths.

The actuator circled in green should be to change POOL or SPA modes.

I think the actuator circled in yellow is for your spillover line. And it is protected by the CV.

If the green actuator is leaking your spa can be draining through it. I cannot not tell in the pic but it does not look like the handle is perfectly centered on the actuator to perfectly close it.

View attachment 360105
For what it's worth, here is a picture of the green circled actuator when it is in Spa mode. I don't think there is anything conclusive from the picture, please let me know what you think. Thank you!
 

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For what it's worth, here is a picture of the green circled actuator when it is in Spa mode. I don't think there is anything conclusive from the picture, please let me know what you think. Thank you!

I think that handle is slightly off center and not fully closing the pipe. The cam needs to be adjusted to close the valve 100% to prevent water leakage through it since you don;t have a check valve before it.

 
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