Hello!!
Hoping some pool experts here may have some ideas on this head scratcher. I have done a considerable amount of research via Google searches (and read this post: https://www.inyopools.com/blog/pentair-minimax-nt-heater-error-codes/) – good blog, BTW. I saw this exact behavior posted on this blog, but no replies (and I posted there today as well). I also got a few clues from justanswer.com, but nothing definitive except perform step 4 below).
I have the Pentair Minimax heater mentioned in post title. I went to run the Spa, turning on via the Intellitouch App on phone. All started, spa pump, blowers/bubbles. Went to go in about 30 mins later and water temp was same as pool (~68 degrees).
I went over to the minimax heater and 1) did not hear the expected heater blower running (I set temp 90 and would expect it to get there in about 40 mins), and 2) looking at the control panel, it was cycling every 4 or 5 seconds with 88.8 (and all LEDs on left and right illuminated), then to --.- (and power, sw pressure, remote and spa LEDS lit. The sequence of 1) and 2) repeat.
Here is the troubleshooting I have done thus far.
1. Power cycled the minimax via power switch inside door. No change, same symptoms and control panel behavior.
2. Removed Power on minimax. Removed control wires from Intellitouch. Power ON to minimax, no change same symptoms.
3. Checked for 24VAC at jumper J4 on control board. Confirmed 24VAC present.
4. Removed power, Replaced control board (pn 274100), same symptoms still…
I have replaced all sensors 3 years ago, have the parts for igniter and flame sensor but have not replaced them yet.
I do see the Red LED briefly illuminate on the ignition control module and then turns OFF after power is applied to heater (I assume this is good, based on info printed on front of module, i.e.appears an LED illuminated means a problem). Not sure, but I think this logic is correct.
As there is 24VAC at the control board (J4), I assume the transformer is good.
I am not getting any ERR0x messages. And, when the entire system is off, I see the expected OFF message on the control board (when control line is from the Intellitouch panel).
The system has worked as expected in past, used about 3 months ago (heat and run spa).
Any ideas? I assume I will need to call Pentair support.
Thx in advance!!