Jandy LXi - Fault High Limit

[Easto]

Ok, so I turned the pool on.
Removed the sensor from the right. Held it in my hand and the heater fired up.


One is in (red dot) , one is out (no dot)

when I reinstalled it, I got the High Limit Fault

In the attached picture, the heater fired up. When I put the sensor back in, the heater shut off and gave me a fault

 

[Easto]

Lastly.

I removed both sensors from the heater. I flipped flopped them.

the sensor with the red dot worked when in either port.

the sensor without the red dot trigger a fault as soon as I installed it into the left or the right port.

if the leave the sensor (without dot) out the heater turns on. As soon as it’s installed it triggers a fault

I am not sure, but I am going to assume this is very telling. Either the sensor is bad, or the heater is.

do these last two posts clarify what’s going on?

 

[setsailsoon]

As I suspected the sensor has failed. Replace it and put them in the correct position. Should solve the problem.

Just to clarify a safety concern. If the heater is firing for a while and shutting down never "jump" the high level limit switches with the unit running. If this is happening remove the connectors with the unit OFF. Check each one for continuity. If off and cold they should be closed circuit. If not the switch is bad. If the unit doesn't fire it can't be overheating. In that case you can short one at a time briefly. But best way is to check for "open/closed" switch without unit running.

I hope this helps.

Chris

 

[Easto]

I turned on the heater and immediately got a Fault High Limit. Heater didn’t even try to fire up.

What I did was remove the sensor from the port. When I did so, the heater started.

The 135 was in the port and I held the 155 in my hand. Upon reinstalling the 155 the heater Faulted.

I removed both sensors from the port and switched the 135 over to the 155 port. Held the 155 in my hand and the heater fired up.

plugged the 155 into the 135 port and immediately got the fault.

I should have a new sensor + harness here tomorrow, thanks Amazon.

I hope that works

 

[Easto]

Installed the new harness with sensors.

heater fired up right away

Let’s hope it stays on!

 

[Rossterman]

We are all crossing our fingers for you!

 

[Easto]

Still going!

 

[Rossterman]

Now wasn’t that better than $3500 for a new heater?

 

[Easto]

Yep!