Have you ever seen a VRF fan coil piped backwards???

[Brandon3131]

That's right...I believe the installer on this job took a few Daikin fan coils and piped the liquid lines to the suction and vice-versa.
:confused:
Question is - has anyone seen this happen before? What will happen on the low side pressure? What kind of temperatures do you see on the saturation and super-heat?

We have a total of (5) fan coils on an RXYQ96MTJU (R-410a) condenser. Basically we are seeing an additional 50 psi of pressure on the low side as soon as one of these (3) suspect fan coils opens the expansion valve. The thermistors within the fan coil read around 59 F or 60F.

Has anyone seen anything like this before??? Cheers

[multisync]

I assume you can access the indoor units and BS boxes? if so it's pretty easy to work out which is which.

I suspect it's possibly a mix up problem of the piping at the refnets rather than the actual units. (hot gas line crossed with the suction??)

[acnerd]

.... on top of which the fan coils have thermistors in them to monitor the entering and leaving temperatures of the refrigerant, which assists in superheat control, defrost, coil reheat in heating mode, etc.

I would change the pipes around!!