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View Full Version : Daikin vrv3 fault varying from ue c9 u5



Reardon963
03-10-2012, 07:59 PM
Hi all never had a problem like this turned up to site today had a vrv3 in fault showing u5 1 unit c9 5 units and other 5 not in fault. 11 indoors off a 10 and 8 condenser. Checked suction pipe thermistors on all units and others in building all showed fine. Noticed who ever commissioned system actually wired into p1 p2 for hard wired controller I guess before I touch was on site. So I disconnected all links of p1 and p2 , didn't touch f1 or f2 reset system and now have ue fault on all units. Now in my eyes this is how system should be and ready to run. I have yet to check all bs boxes for power so that's my first job tomorrow. Any ideas please?

install monkey
03-10-2012, 08:44 PM
ue faulty comms from outdoor to itouch-
c9- suction air thermistor - on the unit no 1
u5 comms error on indoor- remote controller- check 2 core 0.75mmsq flex is connected on n and p on the indoor and check the comms and controller cabling isnt crossed
check f1 f2 ind is ur comms from outdoors to each indoor , daisychained to the last unit.
i touch connects to the outdoor on the f1f2(may not be correct-vrvIII will correct me! haha)
the reset the ring main
go in settings mode to comfirm the outdoor can detect all indoors
power the system down when modifying comms wiring:rolleyes:

Reardon963
03-10-2012, 09:13 PM
Lovely thanks no its the same for a 3 . There's no way they require 5 thermistors but then why has system run for a 12 month which I'd say wiring is correct . Yes outdoor unit picked up all 11 units . Nightmare )

AbsoluteWDJ
04-10-2012, 09:16 PM
Was all the 11 indoor units displaying on Itouch before you reset? It can take a little patience but the UE will display on the Itouch control for a while if you've reset power to either Itouch or an outdoor unit. Once this has happened power down the indoor unit(s) that display U5 for around 20 seconds and then power back up. Also, check the return air sensors on the units with C9, there will definatley be something wrong with these. Whether it be disconnected on indoor PCB or extendable sensors that been wired incorrect. Double check these.

Reardon963
04-10-2012, 10:10 PM
Hi all was back on site today found took all p1 p2 connections out turned all indoor units and bs boxes off along with condenser done reset then went around 1 on at time and running it. Found 1 unit thermistor had gone and UE on 1 unit. No power out of p1 p2. Board powered but found cable been slit when side cover unit was put on id say. Obviously when then wired p1p2 in daisy chain it was confused and showing 2 dif faults on 6 units