Fujitsu Mini Split Error Code 35: Manual Auto Button Error (Meaning, Causes, Fixes)

What the code means

Fujitsu's service manuals list E:35 as "MANUAL AUTO button error (Indoor unit)" and say it's detected when the MANUAL AUTO button is on continuously for 60 seconds or more. The MANUAL AUTO button is the small button on the indoor unit used to run the system without the remote. On units without a wired remote, the indoor unit shows the error as 3 Operation light flashes and 5 Timer light flashes, with the Economy light flashing continuously. The Airstage ASEH07KJCAL service manual lists four possible causes: the button stays pressed, the button has failed, the indoor indicator PCB has failed, or the indoor main PCB has failed. Fujitsu's 410A mini-split troubleshooting guide describes the same 60-second condition and points technicians to a check of the button's on/off switching with a meter.

Likely causes

• The MANUAL AUTO button on the indoor unit is stuck in or is being held down, for example by a front panel or cover that isn't seated right.
• The MANUAL AUTO button itself has failed and reads as pressed even when it isn't.
• A short circuit or corrosion on the indoor unit indicator PCB, the small board the button and lights sit on.
• A failed indoor unit main PCB, which Fujitsu lists as the last cause once the button and indicator board check out.

Safe DIY checks

1. Turn the system off and look at the MANUAL AUTO button on the indoor unit. Make sure it isn't stuck in and that nothing (the front panel, a cover or an object) is pressing on it.
2. If the panel was recently removed for cleaning, reseat it so it sits evenly and doesn't touch the button.
3. Turn the system off at the breaker for a few minutes, then back on, and see whether the code returns. The error is set when the button reads as pressed for 60 seconds straight.
4. Check for moisture or signs of water around the button area, since Fujitsu's manuals call out corrosion on the indicator board.
5. If the button moves freely and the code comes back, call the installer or a licensed HVAC technician.

Parts that commonly fix it

Always match the part number to your exact model.

Related codes

• 11 Fujitsu Mini Split 11
• 22 Fujitsu Mini Split 22
• 53 Fujitsu Mini Split 53
• A1 Fujitsu Mini Split A1
• A3 Fujitsu Mini Split A3

All Fujitsu codes →

Sources

1. Fujitsu Airstage ASEH07KJCAL service manual, E: 35 MANUAL AUTO button error: on for over 60 seconds, possible causes and troubleshooting steps (button, indicator PCB, main PCB), via ManualsLib
2. Fujitsu RSG09KMCDN service manual, 2-8 E: 35 MANUAL AUTO button error (Indoor unit): Operation 3, Timer 5, Economy continuous, via ManualsLib
3. Fujitsu ASUG09LMAS service manual, E: 35 Manual auto button error (Indoor unit): check button and replace main PCB and indicator PCB, via ManualsLib
4. Fujitsu 410A mini-split troubleshooting guide (2019), error 35 Manual auto switch error: on for 60 or more consecutive seconds, meter check