u/JFon101231

Getting an intermittent FL-2 error. Main board was replaced under warranty years ago due to arcing (think they didn't tighten a lug). Opened it up and looks fine rn. Twice in the last month or so have noticed red light on. I opened the main front panel and dont see the little T thing with wires sticking out which seems what I should be replacing. Any help? Thanks!

Edit - once red light comes on, heater doesnt work but everything else is fine. If i cycle the breaker (with 3 mins off), when it comes back on it wont do ANYTHING. Last time it seemed to self-cure after a few hours but right now hasnt yet. At least its warm enough dont have to worry about freezing