Zodiac Jandy JXI400N Problem

[Thegatorvault]

Hey gang.....
Well, I have had my heater for about 2-1/2 years and has been working flawlessly. Last weekend, used it for the first time this season for the kids, and noticed it was making a noise every so often. Sounded like it was shuttering/shaking a bit and then it would go away. This would happen about every 5-10 minutes or so. Weird.

Last weekend, after yardwork and a dip in the pool, I decided to run the spa (and heater) for myself since the water was a little cool. Started up fine and was running. Nice warm water was coming out of the jets for quite a while and then the water went cool. After a little bit, the water turned warm again and I could hear the heater noise when this happened. It would do this cycle about every 5 minutes or so.

I checked the manual and it indicated the temperature regulator valve (TRV) might need to be replaced. Before plopping down $80 to replace this, or calling Jandy and succumbing to frustration, I wanted to get some guidance on this from the board.

Also, with regard to the heater function, is it normal for the heater to cycle on and off? To be honest, I mainly use the heater for the kids so I couldn't tell if it has always done this. I thought maybe if it reached the desired water temp it would do this, but wasn't entirely sure on its function and variability. Maybe if the faulty TRV is causing the shuttering, it is also causing this cycling of warm/cold water?

Thanks in advance for your replies!

 

[ajw22]

The clattering and cycling you describe may be caused by low water flow though the heater.

When did you last backwash your DE filter? What is your clean filter pressure and what is the filter pressure now?

What speed are you running your VS pump? Did you try increasing the speed of your pump and see if the heater works better?

 

[Thegatorvault]

The clattering and cycling you describe may be caused by low water flow though the heater.

When did you last backwash your DE filter? What is your clean filter pressure and what is the filter pressure now?

What speed are you running your VS pump? Did you try increasing the speed of your pump and see if the heater works better?

Thanks for the reply.....

Low flow rate was the other 'root cause' Jandy listed in the manual. I don't believe this is applicable to me since my water features and return flow appear normal. Answers to your questions:

1. Last DE filter backwash was done in August. Generally speaking, because of my screen enclosure, the filter doesn't work too hard (thankfully). Typical backpressure is about 16-19psi.
2. My pump speed is right at 3000rpm. Again, my pump speed hasn't changed since the pool was built and I never had this issue before.

 

[PoolGate]

I have that same heater and the water coming out of it is always hot when it's running. How are you controlling it? The panel on the heater or Aqualink?