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View Full Version : H9 Error - Daikin RY45EV1A



cisgw
07-01-2012, 07:43 AM
Hi All,
Just have a bit of a problem with my Daikin aircon, i have FDY90FV1 indoor unit connected to 2 Daikin RY45EV1. When i switch it on the remote indicates H9, which as i understand is a outdoor themistor error. I have checked the thermistors on both units and they are measuring the correct resistor value for the temp. I have also checked the LEDs on both outdoor units. WHen they are first switched on the Green LED flashes on both for around 15 seconds. then on one unit the green goes off. On the other unit, the green LED continues to flash and 15 seconds later the 2 red LEDS come on. I believe this indicates a sensor problem. My question is should the green LEDs on both units stay flashing and would it be advisable to replace the PCB? i live in a remote area so getting a tech out is difficult.

Any help would be appreciated.

Thanks
Grant

The Viking
07-01-2012, 12:41 PM
The H9 is, as you say, a problem with the ambient air temperature sensor.
The possible causes according to Daikin are:
-Faulty sensor
-Poor electrical connection to the sensor
-Faulty PCB

As you got 2 identical units there, the simple answer is to swap the outdoor thermistors between the 2 units. By doing that you will dis- and re-connect the plugs so any poor connection should be fixed, you also got a perfect opportunity to inspect the cables for damage. Afterwards if the fault still is there, you know that if it is on the same unit it is the PCB and if it is on the other unit it is the sensor.

Good luck


(Just remember to turn the power to the units OFF before you start swapping sensors)