Total Alkalinity and Pentair Pool Heater

[PoolGate]

Looks like only 1 of your exchanger core tubes is corroded and the rest are fine which is odd. The replacement is not hard, but involved. My heater is like $3500 new and I paid around $1200 total for the parts I needed.

Here is my build thread.

Jandy JXI400N - Trouble Air

My Jandy JXI 400N will not fire. Watching it when it tries after 5 seconds the fenwall goes to a single flash of the red led which is listed as the air pressure check. Is it likely that this is the air pressure sensor or some sort of fan? I can hear the fan running when I call for heat. I am...

www.troublefreepool.com

 

[Ahultin]

Pentair Tube Sheet Coil Assembly Kit for Models 400NA 400LP | 474061

Pool Supply Unlimited has some of the best prices when shopping for Pentair Tube Sheet Coil Assembly Kit for Models 400NA 400LP | 474061

www.poolsupplyunlimited.com

 

[dustindclark]

Thanks all for the info. Replacing the heat exchanger seems like the way to go considering that my warranty is toast, I'm going to be maintaining myself going forward, I won't need the heater for at least a couple of months, the unit is relatively new, and it actually sounds like an interesting weekend project. Will pull the old one off to see what I'm getting myself into.

 

[JoyfulNoise]

Thanks all for the info. Replacing the heat exchanger seems like the way to go considering that my warranty is toast, I'm going to be maintaining myself going forward, I won't need the heater for at least a couple of months, the unit is relatively new, and it actually sounds like an interesting weekend project. Will pull the old one off to see what I'm getting myself into.

You’re probably going to want rebuild the header manifold as well so make sure you inspect the internal parts for corrosion and replace as needed. The thermal regulator will likely be shot as well. Make sure you get all new o-rings and gaskets. I’d also have a tube of the high temperature RTV sealant (the orange stuff) on hand. Be careful with the hot surface igniter on the top plate as they get brittle from use. Make sure to check all ground wiring to the control box as the flame sensor circuitry looks at the current to ground to make sure there is a flame check. Poor or corroded ground contacts inhibit that current flow.

Also make sure you have all new fire insulation too. If what you have got soaked or is damaged, replace it.

 

[JoyfulNoise]

There are also YouTube videos for replacing the MasterTemp heat exchangers. I believe @JamesW has those links handy.

 

[Ahultin]

 

[Ahultin]

You’re probably going to want rebuild the header manifold as well so make sure you inspect the internal parts for corrosion and replace as needed. The thermal regulator will likely be shot as well. Make sure you get all new o-rings and gaskets. I’d also have a tube of the high temperature RTV sealant (the orange stuff) on hand. Be careful with the hot surface igniter on the top plate as they get brittle from use. Make sure to check all ground wiring to the control box as the flame sensor circuitry looks at the current to ground to make sure there is a flame check. Poor or corroded ground contacts inhibit that current flow.

Also make sure you have all new fire insulation too. If what you have got soaked or is damaged, replace it.

The link I posted appears pretty complete, including the gaskets, insulation, hot surface ignitor , rtv and the actual heat exchanger

 

[JamesR]

Being a guy who likes to repair everything myself, that’s would I would do as well considering the thing is less than 2 years old. Take plenty of pictures from multiple angles before tearing into it and also during the process. That helps immensely when putting it back together. You can see which way wire harnesses were run, where different screws and bolts went, brackets and so on.
Just curious, does that model heater have the option for a copper/nickel HX upgrade? Adds a bit of corrosion protection.
Regardless….. ditch the tablet feeder.

 

[dustindclark]

Happy to report that the new exchanger is installed and working...just in time for the cold front that's about to blow through. The drum that it sits in was a complete mess, so that was a pain to clean up...but otherwise, it really wasn't all that complicated. I even have a spare igniter.

That said, the heater doesn't seem to perform as well as it used to. I don't have any real data to back this up yet, but the water doesn't feel as hot as it did before on a given pump setting. Maybe I don't have the insulation aligned perfectly? Or maybe the combustion chamber sat in water for too long and rusted...it was almost 3 weeks before a technician looked at it for the warranty claim. I did clean the screen up as best I could with a wire brush. I have not replaced the manifold bypass valve yet...that was going to be the next thing I checked.