Troubleshooting a Furrion Thermostat Giving an E3 Error Code

Updated 05/13/2025 | Published 03/31/2025

Products Featured in This Question

Replacement Wall Thermostat for Furrion Chill HE RV Air Conditioner - Single Zone - Black - R32

(10)

$72.33

Replacement Single Zone Controller for Furrion Chill HE RV Air Conditioner Setup

(33)

$106.90

Question:

I replaced my furrion thermostat and it gives me E 3 code I turned of the power and my solar panel along with the battery the ac comes on for few minuites and shuts off flashing the E3 code again i installed my old thermo stat and ac works . the reason i changed the thermo was my old thermo is off is reads 80 in the trailer and the thermo is set at 73 my unit will not come on so i figured my thermo is bad and i bought a new one and keep getting the E3 code . what should be my next step to take

asked by: Randall M

Expert Reply:

Hey Randall, sorry to hear about that! So an E3 error is a loss of communication between the thermostat and the control box. Since you already power cycled the wires, the next thing I'd do is try connecting the wires from the thermostat directly to the controller. If you're still not getting a resolution after that, then you can try flipping the A & B wires as well to see if that fixes it.

If you're still having issues even after all that, then I'd start with a new thermostat to see if it was an issue with the thermostat itself # FR88TD. If that does not fix it still, then the issue has to be with the controller, in which you'd need the Replacement Single Zone Controller for Furrion Chill HE RV # FR43PR.

If you have any other questions, please feel free to drop a comment and let me know!

expert reply by: Bryce D

Douglas N.

5/4/2025

Getting a code of LO on the fusion thermostat disconnected power disconnected battery waited 24 hours install new battery installed power 250 A. Everything in the unit is working on 12 V and 110 voltage air conditioning was working then stopped before it’s went to LO code blinking blue. I have no control of the thermostat voltage is all good at 13 three voltage.

Jon G.

5/13/2025

@DouglasN The manual for the Furrion thermostat says that the LO code means " Insufficient low level of +12V power supply. System will shut down." Since you've already done some troubleshooting on your own and everything seems like it's okay, I recommend getting a fresh set of eyes on the situation by either having a friend come look at it or having a trailer shop check it out. If everything still looks okay, then you'll need to either replace the thermostat or see if it can still be replaced under warranty.