ccarmock
26-07-2013, 08:05 PM
I have a Daikin multisplit inverter installed at home. The external unit is a 3MX unit with connections 1 & 2 only in use and 2 x FTXS35G2V1B internal units. It is a heating & cooling system
All was working well after installation.
I had a need for the pipework to be disconnected about a year ago so the maintenance enginner did that and reconnected for me. Again all seemed well though unit number 2 seemed less powerful in cooling.
Then unit number 2 stopped cooling altogether and tripped out flashing a UX error. A power cycle reset it and it worked again.
This repeated. The engineer visited again and found that the re conenction of the pipes had one crossed with the other so corrected that.
No 2 indoor unit seemed more powerful now. But has started to have intermittent cooling failures again.
When the system works correctly all seems very normal. BUT in failure mode when number 2 unit only is on I find that the pipes that feed no 1 unti get cold and indeed the coil inside no 1 indoor unit gets very cold.
So refrigerant is going to the non operating internal unit.
I have checked cabling which matches the units correctly.
A power cycle sometimes makes them work again, but I have tried no 1 only no. 2 only and both running and often no 2 will not cool.
What I also notice on the external unit in failure conditions - the upper two pipes for no 1 unit both get cold and the THINNER of the second set of pipes gets cold but not the thicker.
I have an engineer calling next week, but wondered what people felt might be the issue here. Could there be a valve failed that means no 2 gets no refrigerant and when that happens it's forced into no 1?
When no 2 works the fan coil in no 1 does not cool so it is a weird fault.
Any advice much appreciated
All was working well after installation.
I had a need for the pipework to be disconnected about a year ago so the maintenance enginner did that and reconnected for me. Again all seemed well though unit number 2 seemed less powerful in cooling.
Then unit number 2 stopped cooling altogether and tripped out flashing a UX error. A power cycle reset it and it worked again.
This repeated. The engineer visited again and found that the re conenction of the pipes had one crossed with the other so corrected that.
No 2 indoor unit seemed more powerful now. But has started to have intermittent cooling failures again.
When the system works correctly all seems very normal. BUT in failure mode when number 2 unit only is on I find that the pipes that feed no 1 unti get cold and indeed the coil inside no 1 indoor unit gets very cold.
So refrigerant is going to the non operating internal unit.
I have checked cabling which matches the units correctly.
A power cycle sometimes makes them work again, but I have tried no 1 only no. 2 only and both running and often no 2 will not cool.
What I also notice on the external unit in failure conditions - the upper two pipes for no 1 unit both get cold and the THINNER of the second set of pipes gets cold but not the thicker.
I have an engineer calling next week, but wondered what people felt might be the issue here. Could there be a valve failed that means no 2 gets no refrigerant and when that happens it's forced into no 1?
When no 2 works the fan coil in no 1 does not cool so it is a weird fault.
Any advice much appreciated