daikin vrv rsx10ktal

[johnnie]

any advice for u4 code in daikin vrv? the model is rsx10ktal

TYVM

[stufus]

Hey TYVM
U4 is a communication fault,press and hold reset on outdoor pcb then power down and back up .If all is ok should sort it out for you.:)
If you search previous threads there's plenty of answers to this with more info should you need it..

[brunstar]

you may want to check the comms cable between the indoor unit and outdoor unit. Do you have any LEDS on the outdoor unit? If the main fuse on the outdoor control board is blown then this can cause a communication fault.

[troymedhurst]

not sure of exact unit but I had this the other day. if the interconnecting cable is label 1,2 & 3 check that the voltage between 2 & 3 floats between 15 - 45v dc if not replace outdoor board